P030085 & P030485 - MBWorld.org Forums

Mar 3, 2025 | 02:40 AM

Odd Piggy

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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320

P030085 & P030485

2021 GLA 250 FWD, 50,000 miles.

P030085 (misfiring) & P030485 (misfiring cylinder 4) DTCs appeared suddenly. About 10,000 miles ago the cylinder head was replaced because of the exhaust valve problem seen on the M260/264 engines through 2022 model year.

The problem does not appear when the GLA is first started. After about 2 minutes of either driving or idling, the very rough running starts. Although these 2 codes are associated with an exhaust valve failure, the 2 mixture codes are not present. Since the cylinder head was replaced fairly recently, a repeat of that wasn’t expected. Also, when the exhaust valve failed, the engine did not run this rough and did it immediately on start up.

Has anyone seen this misfiring without the cylinder head/exhaust valve failure? If so where was the problem? Spark plugs? Ignition coils? Injectors?

Mar 7, 2025 | 11:33 AM

190Efan

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1991 190E 2.3

I don't own a GLA but I would suggest taking your car back to the MB deler since the issue was reported when the car was still in warranty and the issue hasn't yet been solved.

Mar 8, 2025 | 01:58 AM

Odd Piggy

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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320

Quote:

Originally Posted by 190Efan

I don't own a GLA but I would suggest taking your car back to the MB deler since the issue was reported when the car was still in warranty and the issue hasn't yet been solved.

Brought GLA to dealer. They fixed it without question. Apparently there are some actuators that mechanically shift the camshaft itself or the lifters to vary valve lift depending on power demands. I did not have time to talk to the service tech for a detailed explanation. Actuator failed and damaged the cam. They replaced the camshaft, actuators, and associated components. Service advisor said this was not a common failure.

I test drove it before returning it to our driver. It felt like the GLA I drive. She says it feels better than before which may be an indication that something had been going wrong for a while.