2020 Mercedes-Benz GLE-Class Complaint Log

My vehicle was in for a normal service to have the spark plugs replaced. However I was told that the engine wiring harness had become brittle (apparently a common and reoccurring problem with my vehicle) and would likely cause misfiring after changing spark plugs. This did indeed happen and if I didn’t elect to have the harness replaced, it would have put myself and my son in danger. It was a very costly repair (over $4000) for something that the vehicle manufacturer is at fault for.

The glass between windshield and panoramic sunroof has 2 cracks starting on the drivers side and continuing all the way across to the passenger side. we dont recall an objects hitting the glass.

The contact owns a 2020 Mercedes-Benz GLE350. The contact stated that while driving at an undisclosed speed, there was an abnormal sound coming from the sunroof. The sunroof cover was not opened. The contact pulled over to the side of the road and exited the vehicle. Upon inspection, the contact became aware that the sunroof glass had shattered. The vehicle was taken to the dealer, but was not repaired due to the cost. The vehicle remained at the dealer unrepaired. The manufacturer was notified of the failure but denied assistance in covering the cost of the repair. The failure mileage was approximately 90,000.

Engine compartment heat causes wiring harness insulation to melt and Electrical shorting while driving. Engine has lack of power and acceleration due to heat damage to the engine harness. Check Engine light came on. This is a potential fire risk and should be address by MBUSA. This is a know issue with this model. Car has only 36,000 miles

Cooling system failure due to cracked coolant line beneath intake manifold at 57,000 miles. Part # 264-200-42-01. Sudden coolant loss can cause engine overheating and potential engine stall while driving, posing safety risks. The original part was plastic and has been superseded by manufacturer to metal, suggesting design inadequacy. This was confirmed by Mercedes Benz dealership and also by MB USA. There have been multiple reports by other owners online, indicating this has been a common problem on a 2020 GLE 350. There was also an article in Jan 2022 stating that Mercedes had sent a letter to 800,000 owners informing them of a defect, but no there was no recall due to part shortage. https://www.insurancejournal.com/news/international/2022/01/05/648140.htm Yes, dealership has diagnosed it and confirmed this is the problem. There was a warning lamp/message stating low coolant level, which prompted me to take the vehicle to the dealership. Car has been serviced regularly at the Mercedes dealership. Strong risk of overheating.

My 2020 GLE 350 first displayed a problem with left indicator on front left hand head lamp. I took an appointment with my Mercedes dealer for repair. Then it started showing all kinds of safety problems on the screen -like blind spot monitoring, collision warning etc not working. I parked it in my garage, shut off the engine, locked it and in a couple minutes, it started a blower like sound. I called Mercedes service center and described the problem. They sent a tow truck. While waiting for tow truck, the blower would automatically start every 3 to 4 minutes in a standing, switched off car which can be very dangerous. After diagnostics the authorized service center found the root cause to be a worn out seal which let condensation in the lamp assembly and the water entered in the electrical module. I have taken up the issue with Mercedes corporate. While they are investigating, I wanted to file this complaint so that if there are similar complaints in this model, it may be a manufacturing defect that needs a recall to fix the bad sealing

Cylinder head is defective and needs replacing. It is at the dealer for service at the tune of $7700. The car will not accelerate and sounds like it is in the wrong gear. Upon searching the Internet it seems like there are tons as in 1000’s of 2020, 2021 and 2023 Mercedes GLE 350s all having the same problem. There should be a recall as most cars are seeing this problem at 20,000 to 30,000 miles and at times when it is replaced, it turns around and happens again. Starting misfiring in October and continued to get worse.

After starting my vehicle and placing it into drive, a warning message appeared on the dashboard stating, “Vehicle warning Do not continue to drive,” indicating that the vehicle would be unable to move forward or in reverse. Immediately following the warning, the vehicle lost all ability to move in either direction while other vehicles were approaching, creating a hazardous situation placing my safety at risk. I was required to keep my foot on the brake and ultimately place the vehicle in the park position. The vehicle was subsequently towed to the dealership. Following diagnostic testing, the dealership confirmed a transmission solenoid valve fault in the control unit and recommended replacement of the transmission valve body and park pawl solenoid, along with a transmission service. The condition was confirmed by the dealership, and there were no warning messages, indicator lights, or symptoms prior to the sudden failure.

The contact owns a 2020 Mercedes-Benz GLE350. The contact stated that while driving at various speeds, the vehicle failed to accelerate as intended while the accelerator pedal was depressed. The check engine warning light was illuminated. In addition, the contact stated that while the vehicle was stopped, the vehicle was idling low. The vehicle was taken to a local dealer, where it was diagnosed with a misfire in cylinder #4. The vehicle was not repaired. Upon further investigation, the contact related the failure to a NHTSA recall; however, the VIN was not included. The manufacturer was made aware of the failure. The failure mileage was approximately 100,000.

Wire harness need to be replaces car is under 100k miles and the same issue has been recalled cla250 gla models with the same engine. Current model GLE is not under recall but has the same issue with the electrical issue “oil pump vavle connector fault” which cause engine light .

I am writing to express serious concern regarding a potentially dangerous mechanical issue with my Mercedes GLE 350. The vehicle has experienced a complete cylinder head failure, requiring an estimated $7,000 repair. Both an independent service center and an authorized Mercedes service center have confirmed this diagnosis. During the inspection process, Mercedes conducted two diagnostic tests—one costing $250 and a second costing $700—before determining that the cylinder head must be replaced. I was informed by the Mercedes service advisor that the company is aware this issue has affected other GLE 350 vehicles; however, no recall has been issued to date. This failure presents a significant safety risk. The vehicle suddenly loses power without warning, and acceleration becomes severely limited, often not exceeding 20–40 mph even when pressing the accelerator fully. The check engine light illuminates at the time of power loss, leaving the driver unable to maintain safe highway speeds or merge with traffic—posing a serious hazard to both the driver and others on the road. Given that this appears to be a known issue, I am requesting immediate review and investigation by Mercedes-Benz. A recall or formal service campaign should be considered to address this potentially dangerous defect and to ensure the safety of all affected drivers. Thank you for your prompt attention to this matter.

The contact owns a 2020 Mercedes-Benz GLE350. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the fuel pump. The vehicle was repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 23V445000 (Fuel System, Gasoline), but the VIN was not included. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 79,000.

Engine Cylinder Head Failure on CPO Mercedes-Benz GLE 350 Vehicle Information: •Make: Mercedes-Benz •Model: GLE 350 •Year: 2020 •Mileage at time of issue: 90,000 Summary of Complaint: The vehicle experienced a premature cylinder head failure, resulting in significant engine damage and repair costs. There were no prior warning lights or diagnostic codes indicating a problem before the failure occurred. The malfunction caused sudden performance issues, including rough idling, misfiring, and loss of power. Details of the Incident: While operating the vehicle under normal driving conditions, the engine began to run roughly and lost power unexpectedly. Diagnostic testing revealed that the cylinder head had failed, which appears to be a mechanical or manufacturing defect rather than wear and tear. The repair estimate from the dealership was approximately $8,900, which is disproportionately high for a vehicle of this age and mileage. Safety Concerns: This type of failure could lead to sudden engine shutdown or loss of power while driving, posing a safety risk to occupants and other drivers on the road. Manufacturer Case Reference: This issue has also been reported to Mercedes-Benz under case number 18281587. Additional Information: After research, it appears that other Mercedes-Benz GLE owners have reported similar issues related to engine component failures, suggesting this may be a broader quality or manufacturing issue that warrants investigation. Requested Action: Requesting that NHTSA investigate potential defects in the engine or cylinder head assembly for the 2020 Mercedes-Benz GLE 350 and determine whether a recall or service bulletin is appropriate.

Air bag warning light

Check engine light came on September 2025 and the initial diagnosis was for mixture formation (cylinder 3) is irregular. Issue with the GLE 350 years 2020 to 2022 (from what I saw online) is the engine has an issue with a faulty cylinder head. This issue while driving causes the car to shake. This faulty cylinder has been confirmed by the Mercedes Benz service shop.

The main multimedia screen in the car has failed and is malfunctioning. Rear view parking camera only works some of the time. No access to temperature control. No access to navigation. No access to multimedia. The lack of functioning camera system has put myself and others at risk during parking and driving. This has been reported as a recall in the past (NHTSA 21V354, MBUSA Campaign 2021080009) and has been reportedly completed. My concern is that this repair/fix dis not sufficiently address the root of this issue and now the problem has returned.

Transmission Control Module / Valve Body failure occurred at 44,000 miles

The air conditioning in my 2020 Mercedes-Benz GLE SUV has failed due to a refrigerant (freon) leak, leaving the system unable to cool and properly defrost the windshield. This is not an isolated issue—many other GLE owners have reported the same failure on forums and blogs, suggesting a widespread defect. NHTSA has already issued Recall No. 23V177000 (March 2023) for improperly installed A/C drain hoses in 2020–2021 GLE/GLS models, which created water intrusion, electrical shorts, fire risk, and failures of critical systems (eCall, unlocking, limp mode). In addition, a Mercedes-Benz Technical Bulletin dated August 5, 2024 (NHTSA MC-11000597-0001) specifically identifies evaporator refrigerant leaks as a frequent cause of A/C failure. Safety Concerns Loss of cabin cooling in hot weather poses risk of driver fatigue or heat-related illness. Defogging/defrosting may fail in humid conditions, creating visibility hazards. Prior related A/C defects have been tied to short circuits and electrical risks. Consumer Impact This defect has created significant hardship. The A/C failure occurred far earlier than expected for a premium vehicle, leaving me with high out-of-pocket repair estimates. The lack of cooling makes the car unsafe and uncomfortable to drive in hot weather, and the inability to properly defog/defrost windows compromises visibility. I purchased a Mercedes-Benz with the expectation of reliability and safety, and this known defect has undermined that trust. Requested Action Mercedes-Benz should cover the repair costs for affected vehicles, and NHTSA should investigate whether an expanded recall is necessary to include A/C evaporator refrigerant leaks as part of the broader HVAC system defect.

The contact owns a 2020 Mercedes-Benz GLE350. The contact stated that while driving at low speeds, the vehicle entered LIMP Mode but continued to operate with reduced motive power. The contact was able to pull over to the shoulder of the roadway, where the failure persisted. The check engine warning light was illuminated. The vehicle was towed to an independent mechanic, who diagnosed the vehicle with engine control unit failure causing the engine to run lean, resulting in misfires in cylinders #1 and #2 and damage to the engine. The contact was informed that the engine had failed a pressure test and needed to be replaced. The contact was advised to take the vehicle to the dealer for assistance. The vehicle was towed to the dealer, who confirmed the diagnosis and determined that the failure could be resolved with a top end engine replacement of the cylinder head, valves, valve springs, rocker arms, camshaft, spark plugs, and valve cover. The vehicle was not repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 71,000.

My 2020 Mercedes-Benz GLE 350 experienced a complete engine seizure at approximately 60,000 miles without any warning signs. The vehicle shut down and would not restart. The engine is completely inoperable. I am aware of recalls involving engine stalling and fuel system issues in this model, and I believe this may be related to a broader defect. Mercedes-Benz has not offered support as of this writing.

My car shook while idling the last two weeks of June 2025. It felt like it was going to shut off at light/stop sign which it did on two occasions. On July 2, 2025, it stalled abruptly during a drive after which I took it to Mercedes for service. I never received a warning signal or fault message even after it stalled. Mercedes service indicated the engine cylinder head valves were burnt and not sealing properly - estimated cost of repair $10,023.00. I am the original owner of the car, had routine maintenance and only had it performed at Mercedes. My car stopped without warning- but luckily on a local road. Others who are driving with this defective engine may not be so lucky. It appears this is a known issue to Mercedes USA but they have not done anything to fix it. The engine is M264. Even if valves are replaced, this problem may continue to occur as the Mercedes serviceman does not know what caused the burnt cylinders - just that they needed to be replaced and that it was not wear and tear. Not sure if this is related, but there was a 2022 recall on this engine (my car was not part of batch that was recalled) regarding turbo charger oil feed and return lines. The issues included engine vibration at idle and loss of power.

The rear shock absorbers have failed on my vehicle. The vehicle makes sounds when going over bumps in the road. There is an active recall on other GLE 2020 450 models but not my specific VIN. The vehicle has less then 30,000 miles on it before the shock absorbers went out.

I purchased my 2020 Mercedes GLE 350 new with only 12 miles on it. I also purchased an extended warranty which gave me 100,012 miles. On a Friday evening while being driven, the engine light came on. I took the truck immediately to the dealership on Monday morning. Prior to that the engine would roar loud upon starting on some occasions then calm down. When I mentioned it to the service department on previous service visits they told me it was fine and they notice that, that particular model does that when it gets hot outside. The vehicle also quit on me in the middle of the road before starting back up in about 3 minutes but on a separate visit. ALL my maintenance and service have ALL been done at the Mercedes service department so I'm confused how this happened. So, the dealership needed an extra day to diagnose so after 2 days I was hit with the news that is was a cylinder head...$9,963. I had 108,152 (out of extended warranty) miles on my truck. I notice this is a common issue with this particular year and model GLE350. I also see that Mercedes has a recall on other models just not this one. A recall is needed immediately. I pray this complaint will help others that will experience this same issue in the near future because there's no help for me now.

The vehicle recently experienced a cylinder head failure, confirmed by a diagnotic code P0302 (Misfire in cylinder 2), resulting in rough idling, reduced power, and potential safety risks during opreration. This issue appears to be a known defect in the M264 engine, as evidenced by similar complains from owners of GLE 350, GLC 300, and other models on forums like [XXX] and [XXX] . The failure occurred just beyond the standard 4-year/50,000-mile warranty, and Mercedes-Benz USA denied my request for a goodwill repair despite acknowledging similar issues in related models under extended warranties. Repair costs are estimated $8,000 to $13,500. I believe this defect warrants investigation due to its prevalence and potential to cause sudden power loss, which could lead to hazardous driving conditions. I urge NHTSA to investigate the M264 engine in the 2020 GLE 350 for a possible recall to protect owners and ensure safety. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Hi! I just received word that my 2020 GLE350 will need a replacement cylinder head. I went to the dealership due to having a check engine light on (light came on this morning and I promptly brought to the dealership). It is an $8,000 repair. Upon doing a quick websearch for replacement cylinder heads for 2020 GLE350s, I am finding a lot of people in web groups reporting that they are having the exact same issues for the same model (2020-2022) right after the 50,000k mileage mark (out of warranty). I have always done my maintenance directly with the dealership. Links to the chat forums with similar issues - can pull up more if needed. [XXX] Let me know if you need additional information - thank you! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Strong raw gasoline odor in cabin, making passengers “light headed”. Called dealer about a fuel system recall on this model however they said my vin number didn’t fall under the recall.. no warning lights are on

Bought a 2020 Gle 350 used with 55000 miles on it. Within 3 weeks the check engine light comes on and the car goes into limp mode. Cannot drive it. Took it to Mercedes of Wilmington. They said it was a misfire on 4. They replaced all spark plugs and the coil to cylinder 4. Another month later the same thing happens. Took it back to Mercedes. Stated the car needs a new cylinder head at the cost of 12000$. This seems to be a common problem on these vehicles. A recall is needed immediately

The rear seat belts are faulty. I had to pay out of pocket for the rear middle seat belt repair and now the rear right side is faulty and does not budge or move pass a point. I am concerned that each time these do not work, I will be out another thousand dollars for repair. Seat belts on some of my oldest cars continue to work. This should not be happening especially to a newer vehicle. I need help and by that I want Mercedes to cover the cost. It's very stressful. Thank you for hearing my concern.

Both left and right headlamp/turn signal/marker light assemblies and control modules have been replaced. One under warranty in 2023, the second in 2025. Infotainment system displays error messages Messages may increase as assembly/control module becomes increasingly dysfunctional.

At 48,000 miles the cylinder head needed replaced. This was done under warranty. At 73,000 miles the engine started making a horrible noise and power was lost and acceleration very choppy. Had it towed to the dealer. Dealer diagnosed the issue as a Rod bearing failure and requires the engine to be fully replaced. This occured while driving, fortunately I had just gotten off the highway, otherwise the vehicle would have lost acceleration and speed and would have created and unsafe situation. The engine light never came on, neither before or after the noise and loss of acceleration.

Coolant pipe under intake manifold made of plastic leaking, could have caused engine overheating and failure in traffic conditions. New style pipe supplied by manufacturer is now made of steel, dealer had in stock indicating a repetitive problem.

Turbo oil separator blocked, causing internal pressure pushing oil out of the rear main crankshaft seal. Since the oil level is monitored electrically (no dipstick), the engine can run out of oil, resulting in catastrophic failure while driving, causing a dangerous condition or accident

Cylinder misfire at low mileage with very costly repair.. Vehicle needs cylinder head.

48V battery issue cause the car not able to drive.

My vehicle has developed problems related to the cylinder head, leading to persistent misfires, rough idling, and an illuminated check engine light. Upon diagnosis at an authorized Mercedes-Benz service center, it was determined that the cylinder head requires replacement

As many other GLE 350 owners reported on various forums, same thing happened to me. My car suddenly started shaking and some cylinders misfiring. My car is just 2020 and barely got 60,000 miles on it. Initial report shows that two cylinders misfires with no reason. It's failing the emission and car will not pass emission test anymore. Mercedes says it's out of warranty and asking 15k to replace cylinder head.

Water intrusion. It rained, water leaked into driver seat floor. The water then made it to the electrical parts underneath the driver seat. This seems identical to the recall I am seeing online with the number: 23V-177

Campaign No. 2022030003, April 2022 My vehicle is experiencing the exact same issues, but the VIN was not tagged as one of the affected.

There is a leaking valve seat in the cylinder head 3. This causes the cylinder to lose compression, the car to lose power, and the vehicle fails to move from a full stop.

The rear shock absorbers failed at approximately 33,000 miles. The issue presented with a rattle in the rear end of the car. A certified mechanic diagnosed the issue as the rear shock absorbers were leaking potentially due to improper sealing of the shock absorbers. The certified mechanic presented a document related to a Recall Campaign that is directly correlated to the rear shock absorber issue (please see attached file). The Recall Campaign specifically mentions the vehicle in question ( 2020 Mercedes GLE350) , but my vehicle VIN is not included in the recall campaign. Therefore, the dealership will not fix the issue under the recall campaign. I would like to investigate the remedies available under the current situation.

This is a known issue with GLE 450 48v batteries over heating and causing loss of power and all function to control the vehicle. , For an unknown reason my vehicle was not part of a recent recall and probably should have been. I experienced the issue today and escaped tragedy. My battery light came on, then off, then a bright red battery light came on across the dashboard…then all of a sudden, my car lost all power with no warning. All while driving on the freeway 394! Luckily traffic was light and I was able to coast halfway up an off ramp. Then I got an overheating message. Reports show all cars were recalled, however mine wasn’t part of the recall!! I would like an investigation to include all cars in the years and models not just some of them.

Watch this report: [XXX] There was less than 1/2 a pound of refridgerant in my vehicle. The dealership - Mercedes Benz of Boerne inspected it. They extracted the refridgerant from the vehicle and hooked up leak system and monitor the gas to see if there is a leak and picked up in the center vent and the hose that goes to the vehicle's AC evaporator. There is a leak from the evaporator. This is a recurring problem that has popped up due to a recall in 2019: "The issue stems from air-conditioner drain hoses that may have been incorrectly installed, causing water to drain into the passenger compartment. Water intrusion into the footwells may cause corrosion or short circuits to electrical components, increasing the risk of fire. Furthermore, the emergency call feature may be disabled and the doors may not unlock, increasing the risk of injury. And as a final consequence, the engine may not start or may enter a limp-home mode, increasing the risk of a crash. To fix this potentially long-reaching issue, dealers will inspect and reinstall the drain hoses, as necessary, for free. Owner notification letters will be sent May 16, but those with further questions can contact Mercedes at 800-367-6372, the National Highway Traffic Safety Administration’s vehicle-safety hotline at 888-327-4236, or visit its website to check their vehicle identification number and learn more." INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The air conditioner is constantly leaking refrigerant due to a potential damaged hose which is a known issue for Mercedez-Benz SUVs. I contacted the dealership who advised this is not an issue currently being addressed by the manufacturer and would be at the cost of the vehicle owner.

The contact owns a 2020 Mercedes-Benz GLE450. The contact stated while reversing, the rearview camera was inoperable. The message "Active parking Assist and Parktronic inoperative - See Operator's Manual" was displayed. The vehicle was taken to the dealer, where an unknown software update was performed; however, the failure persisted. The vehicle was taken back to the dealer, where it was diagnosed that an unknown wiring harness had experienced an electrical short due to water entry underneath the floorboard. The dealer informed the contact that the parts were not available for the repair. The vehicle was not repaired. The manufacturer was notified of the failure and confirmed that parts were not available. The failure mileage was 26,994.

This past week, I went to the dealer for an intermittent engine light issue. The problem was minor and was fixed (faulty charcoal sensor). I asked to have my spark plugs replaced as well. The service department called me, and said that the engine harness is brittle and if they accessed.. it could break. This was not considered an immediate issue. Quote was $7300 to replace it. This seemed like a defect rather than an standard wear issue (even though I drive a lot, @ 170K highway miles). My car drives like new, and has had no major issues whatsover. In fact, it is only now that I need to have my rotors replaced. Had I not mentioned that I wanted new spark plugs, the issue would not have came up during the service. I hope that you can look into this, as other Mercedes GLE 450 owners make have the same issue as I. Please do not hesitate to reach out to me. [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The cylinder head which lead to engine problems after the repair it lead to a failure of the positive crankcase valve.

The contact owns a 2020 Mercedes-Benz GLE350. The contact stated while driving at an undisclosed speed, the air conditioner failed to operate. No warning light was illuminated. The vehicle was taken to the dealer where it was diagnosed and determined that the A/C evaporator and A/C receiver drier needed to be replaced. The vehicle was not repaired. The contact stated that the issue was a known failure. The manufacturer was made aware of the failure and a case was opened. The failure mileage was approximately 62,000.

There were two incidents that had similar symptoms: one before the dealership said they fixed and one afterwards. The issue is that while driving I would get three warning, all at the same time: coolant too hot, 48v battery malfunction, shut the engine off. The first time it happened immediately after I turned on the vehicle and within 5 minutes of leaving a parking lot. The second time it happened after about 3 hours of driving at highway speeds. After the first time it happened dealership said they fixed the issue by upgrading the software (battery software?). Both times it happened on the highway. The first time on the uphill, and vehicle immediately shut off and could not make it up the ramp. The second time in the tunnel on the flat road, could not make it to the exit. Both times created extremely dangerous situation as I had no time to take the exit and vehicle shut off about 30 seconds after warning popped up. The second time in the tunnel was especially dangerous as there was no shoulder and i had to stop in the middle of the right lane as cars were going at 60 mph by me. I was really worried for myself and my family. I have to trust that Mercedes is capable of fixing the issue and providing a reliable vehicle I can depend on and trust for the safety of my family.

1)Wiper does run smoothly right from the time the car was purchased. 2) recently the glass window of passanger seat at the back opens very slowly when the button is pushed to pull the glass down.

Component or system failed: P030385 Combustion misfiring of cylinder 3 has been detected. There is a signal above permissible limit value. P030085 Combustion misfiring has been detected. There is a signal above permissible limit value. P1CEF85- Injector injection quantity adjustment for cylinder balancing has almost reached upper limit value at least one cylinder. There is a signal above permissible limit value. P1CE577- Injector injection quantity adjustment for uniform mixture formation has detected an excessively lean mixture in at least one cylinder. The command position cannot be reached. P219E77- Mixture formation (Cylinder 3) is irregular. The command position cannot be reached. I have taken the vehicle into an independent service provider to be evaluated, which is where I received the information for the codes above. The vehicle is now at the dealership being evaluated. A check engine light has been present. There has not been a complete mechanical failure or safety issue due to this specific concern; however, this is a growing concern with this engine, and there is already a similar complaint with these exhaust valve components in other Mercedes models.