Mercedes A-Class Forum banner
261 - 280 of 554 Posts
Hi, it's me again. I had my cylinder head replaced in my 2020 GLB 35 at 37000kms.
Its been driving wonderfully since, until Friday.I've now hit 47000kms and a connecting rod has exploded through the engine block. Parts of the piston are laying in the engine bay. Oil and coolant everywhere. Tonne of smoke. Unbelievable.

I genuinely want a new car out of this, not just a new engine. I was in the countryside (4 hours into a road trip); and at a minimum, MB will need to reimburse me for last minute accommodation and the rental car I hired to continue my trip and get home, along with a brand new engine.
 
Really sorry to hear about your ordeal. I agree MB should offer you another car. I cannot believe that the engine fix is just a sticking plaster until the next time. It’s highly short sighted of Mercedes.
 
MB will need to reimburse me for last minute accommodation and the rental car I hired to continue my trip and get home
In the UK, we get 3 years comprehensive cover for events such as this, breakdown recovery, and if stranded, up to 3 days complimentary car hire, and if unavoidable, MBUK will also cover overnight accommodation and taxis on a case by case basis.

Is there the same level of cover in Aus?
 
Will do, I am keen to get some recognition from the dealer that this is a common fault.
My A35 is a July 2019 car and has 25K on it so its been around a bit more than some of the folks that have experienced this. But 25K to me should not necessitate a new head or even top end rebuild.
 
Will do, I am keen to get some recognition from the dealer that this is a common fault.
My A35 is a July 2019 car and has 25K on it so its been around a bit more than some of the folks that have experienced this. But 25K to me should not necessitate a new head or even top end rebuild.
People in the UK, and other countries, have only had the engine repaired. With one member who was given the opportunity to give the car back. It's an MB fault so I would think that is where the additional compensation would need to be offered from. But please do let us know if you have any luck.
 
Used AMG cars here in the UK come with a 2 year warranty. E.g. I bought mine in January this year @ just over two years old. The original manufactures warranty didn’t expire until November 2022, but because I was buying it used. My warranty now lasts until January 2024.

I hope therefore that @C9311 ’s car is still under warranty. I still cannot understand why there hasn’t been a Mercedes’ recall on this as it really tarnishes ownership 😔
 
  • Like
Reactions: C9311
Don't know yet, I'd only had the car 7 weeks when the fault developed, its been off the road for a further 7 weeks whilst I've been arguing with where I bought it to get them to either repair it or refund me. I'll get a decision on Monday after a frustrated email invoking consumer protection which I sent last Friday.

Been a massive faff and I'd say if anyone had the balls and spare cash you could probably get an expert witness to say its a design flaw in court and have merc cover the full cost.
 
Don't know yet, I'd only had the car 7 weeks when the fault developed, its been off the road for a further 7 weeks whilst I've been arguing with where I bought it to get them to either repair it or refund me. I'll get a decision on Monday after a frustrated email invoking consumer protection which I sent last Friday.

Been a massive faff and I'd say if anyone had the balls and spare cash you could probably get an expert witness to say its a design flaw in court and have merc cover the full cost.
Sorry you’ve joined the forum in such circumstances.

The cylinder head issue is well known in the A35 and I am sure the garage and MB would have just gone ahead and repaired it. The garage has not been able to think outside the box because you have an A250. But it is the same engine as the A35 with FB reports of the same fault. I would contact the UK MB ceo. If you can’t find his email I will dig it up for you when I’m next at my laptop.
 
  • Like
Reactions: C9311 and srea064
Sorry you’ve joined the forum in such circumstances.

The cylinder head issue is well known in the A35 and I am sure the garage and MB would have just gone ahead and repaired it. The garage has not been able to think outside the box because you have an A250. But it is the same engine as the A35 with FB reports of the same fault. I would contact the UK MB ceo. If you can’t find his email I will dig it up for you when I’m next at my laptop.
I'll see what Monday brings!

I'm not a mechanic but I'm handy enough and this seems to be the issue they're suffering from.

The issue it seems is that engines used to inject fuel over the intake valve port which washed away any oil deposits on the valve (which leaks past the valve stem seal) before combustion, now they inject fuel straight into the cylinder not over the valve so any oil that leaks over the valve is involved in combustion which 4 stroke oil isn't meant to be burnt so it leaves residue/deposits, eventually these build up and the valve can't close fully anymore so you get low compression and a misfire. Design fault.

Same way the RX-8 rotary engines used 4 stroke oil from the sump to lubricate the rotar-tips which obviously left residue so some people converted them with a sohn adapter to use 2 stroke oil from a separate tank which is designed for combustion.

Edited to add, if you look at 3rd party warranties they all (that I've seen) exclude carbon build up on valves - as if they know its a problem (not just for MB)?
 
I've just had my 3.5yr old A250 with 32500 miles diagnosed with low compression by MB of Stevenage. The tech was pretty fast to diagnose it as such, I assume the theme is very common. Luckily I got the extended warranty, so didn't have to argue is all covered by them.

Currently car is back with me, until they can source the parts. They did mention this a big job and need 15h of labour approximately.

I have documented my story in another thread here.
 
I've just had my 3.5yr old A250 with 32500 miles diagnosed with low compression by MB of Stevenage. The tech was pretty fast to diagnose it as such, I assume the theme is very common. Luckily I got the extended warranty, so didn't have to argue is all covered by them.

Currently car is back with me, until they can source the parts. They did mention this a big job and need 15h of labour approximately.

I have documented my story in another thread here.
Interesting they gave you it back, I'm on a courtesy car (GLB200) because they said it would be dangerous to drive??

Good to know MB extended would cover it, might be worth paying the extra vs a 3rd party.
 
Interesting they gave you it back, I'm on a courtesy car (GLB200) because they said it would be dangerous to drive??

Good to know MB extended would cover it, might be worth paying the extra vs a 3rd party.
In any case this is the CEO's email. mbceooffice@daimler.com
 
In any case this is the CEO's email. mbceooffice@daimler.com
I guess they couldn't afford me being on the loaner for weeks until the parts get in. They did say, if it does misfire to call them and get it in.

When it does misfire, it works fine when you restart the engine. I suspect the ECU cuts fuel to the cylinder registering errors above a threshold, but it resets after you shut off.
 
I guess they couldn't afford me being on the loaner for weeks until the parts get in. They did say, if it does misfire to call them and get it in.

When it does misfire, it works fine when you restart the engine. I suspect the ECU cuts fuel to the cylinder registering errors above a threshold, but it resets after you shut off.
Yes same experience for me, stop start and it goes away. I'll report back in on my progress.
 
Got a phonecall from the service manager at MB of Stevenage. Parts are in, but they don't have service slots available until 2 weeks later... So have to wait a bit more.
They asked to keep the car for 4 days (of the 3 initially) to be able to do the job. I'm fine with it, just want them to do the job properly.
 
Got a phonecall from the service manager at MB of Stevenage. Parts are in, but they don't have service slots available until 2 weeks later... So have to wait a bit more.
They asked to keep the car for 4 days (of the 3 initially) to be able to do the job. I'm fine with it, just want them to do the job properly.
That's actually very quick for the parts. MB must have a batch shipment ready ready for this engine now.
 
That's actually very quick for the parts. MB must have a batch shipment ready ready for this engine now.
I hope that is the case and they are not cheating in any way with used parts. On the other hand, they must be monitoring parts availability and adjusting orders to suppliers accordingly. I suspect every M260 engine built prior to November 2021 is likely to be affected.
 
Update: the car finally gave in, misfires became more frequent so had it towed tot he dealership.

Road assistance needed like 6h to come due to lack of resources, so brought the car home (was just a couple of miles away) and had them come in first time in the morning. Still waiting for a loaner, no cars available!! Is just madness how everything is overbooked arm

Is it like this in the rest of the country or is it just London?
 
261 - 280 of 554 Posts