M272 V6 engine durability

[clk208]

Daydreaming about car replacements for myself in the next year or so and a nice petrol CLS may be on the cards if prices keep falling. I would probably be looking at the earlier cars but perhaps up to 2006/7.

I've had the CLK for getting on for 6 years and would probably keep the replacement for a similar time.

Scary stories on t'internet about dodgy balancer shafts and timing gear that seem to point towards inevitable failure of all of these engines on pre-2008 models, big repair bills and not great hopes for goodwill repairs for out of warranty used purchasers.
Here's an example of some:
http://www.mbclub.co.uk/forums/engine/124888-272-engine-balance-shaft-problems.html
Class Action suit over M272 M273 - MBWorld.org Forums

Do any of these engines do big mileages without crumbling to pieces? A search on autotrader for E-classes from 2005 with the 350 petrol engine I was expecting to see some huge mileage examples but the highest on the market seem to be 100K ish

Anyone ideas of what mileage one could expect to run these to before expensive engine problems? What would a typical repair cost be? The US sites where the failures are more common (more of these on the roads) talk about $6000 repairs at main dealers. What would a UK indie charge?

 

[oldmerc]

I also posted a similar thread about a month ago regarding Shafts and Sprockets wearing quickly and saw zero replies :-( Hope you have more luck as im very interested in owning 3.5l petrol Merc.

 

[clk208]

Indeed. We must have some high mileage 2005-on petrol V6 owners on here!

I found this bulletin interesting:
http://www.motor-talk.de/forum/aktion/Attachment.html?attachmentId=681441

You can clearly see the wear on the gear on page 3. How easy is it to access this part to view? If I could see it on a potential purchase before buying to establish how worn or otherwise it was it might put my mind at ease!

 

[bobmedley]

I have a 2005 W164 ML350 with the M272 engine & it's now done 126k miles. Unfortunately, it is throwing the codes that point towards the balance shaft issues, the engine is also leaking oil from the back (as is the rear differential and the steering), COMAND has stopped receiving satellite signals, the driver's seat has split, recently the thermostat blew (£200), rear SAM blew (£600) and Xenon levelling unit blew (£250) - all this despite a Merc dealer history with all services as per the display.

I've been offered around £6k as a trade-in (they don't know about the CEL light and other problems yet - local dealer quoted £800 to replace the rear diff seal and £200 just to investigate the engine leak), so if the repair is c£3-4k as per the US forums, then the car is effectively scrap.

I paid £40k for it in March 2006.

Sorry about the rant - in answer to your original question avoid any pre 2008 350 petrol engine.

 

[clk208]

I have a 2005 W164 ML350 with the M272 engine & it's now done 126k miles. Unfortunately, it is throwing the codes that point towards the balance shaft issues, the engine is also leaking oil from the back (as is the rear differential and the steering), COMAND has stopped receiving satellite signals, the driver's seat has split, recently the thermostat blew (£200), rear SAM blew (£600) and Xenon levelling unit blew (£250) - all this despite a Merc dealer history with all services as per the display.

I've been offered around £6k as a trade-in (they don't know about the CEL light and other problems yet - local dealer quoted £800 to replace the rear diff seal and £200 just to investigate the engine leak), so if the repair is c£3-4k as per the US forums, then the car is effectively scrap.

I paid £40k for it in March 2006.

Sorry about the rant - in answer to your original question avoid any pre 2008 350 petrol engine.

Sounds like a really disappointing experience you've had with your MB, sorry to hear.

I saw a rerun episode of top gear a couple of months ago with a W219 CLS when they were just being launched and they were on about it being a huge turning point in build quality and reliability.

Alright, you might not get the rust bubbling on the arches any more but I think I would prefer this (which can be satisfactorily fixed for several hundred pounds) and a cabin that perhaps doesn't have as high quality materials as you'd expect on the 2000ish models over the potential issues on the newer cars. I mean effectively it seems to be just a ticking time bomb waiting for it to eat the timing gear and be rendered unusable.

Then I look at the diesel engines fitted to the CLS and see hefty bills for engine bearings, inlet port shut off motors and manifolds and they seem to be just as bad.

Might have to rethink my next car move which is disappointing as I am a fan of the brand in general and my CLK has been a pleasure to own.

In your case with a FSH and presumably only 1 former owner it may be worth pursuing a goodwill repair from MB though?

 

[bobmedley]

Thanks for the reply - it has been a huge disappointment (I have owned three ML's), so I am now looking to trade this one in and jump brands.

Merc UK's attitude to goodwill as relayed to me is 'nothing over 100k miles or 5 years', although I've no doubt there are exceptions. The Americans appear to be getting some contribution, it looks to average around 50% so still leaves you with a £2k bill on a car worth £6k - not worth the risk when the diffs are leaking (apparently another £4k each) and the gearbox is getting clonky.

 

[st4]

That is a scary read that thread on Benz world...

 

[Dieselman]

Indeed. We must have some high mileage 2005-on petrol V6 owners on here!

I don't think anyone has reported going past 200k in a V6 petrol, yet.

It looks like timing belts may be the way to go here. They need replacing at about 70k, but if chains and sprockets are only lasting twice that, it's a lot less hassle in the long run.

 

[Bellow]

Why does a V6 need a balancer shaft? Is it a 90 degree bank angle V?

 

[Dieselman]

Why does a V6 need a balancer shaft? Is it a 90 degree bank angle V?

Yes, which is why it needs the balancer.

 

[Bellow]

Yes, which is why it needs the balancer.

Then what MB have to do is make a 60 degree V6 and ditch the balancer shafts and retain the chains. Anything less is a fudge.
What happened to ''The best or nothing''? So far nothing seems to be all that's offered with this engine.

PS.
Anyone seen Diesotto? Been looking everywhere... still no sign...Too complex for production you say?

 

[Dieselman]

Then what MB have to do is make a 60 degree V6 and ditch the balancer shafts and retain the chains. Anything less is a fudge.

They already had the tooling for V8 engines, so have used that to make the V6. Not ideal.

 

[Bellow]

They already had the tooling for V8 engines, so have used that to make the V6. Not ideal.

This is the kind of thing the Yanks were doing decades past and boy do they have a reputation for cracking motors....

MB need to get it together. When Ford Pinto engines were wiping out cams, W123s were clocking 200-300,000 trouble free miles. What has happened in between?

 

[clk208]

This is the kind of thing the Yanks were doing decades past and boy do they have a reputation for cracking motors....

MB need to get it together. When Ford Pinto engines were wiping out cams, W123s were clocking 200-300,000 trouble free miles. What has happened in between?

It's not ideal to have these defects on pretty fundamental bits of drivetrain. You'd think it would have shown up during testing really. Plus these engines will generally be so understressed, cruising at rapid motorway speeds using only a few % throttle. Compare this to a W123 engine which would have been working a lot harder to make reasonable progress on the road and it shows the durability must have gone down hill somewhat.

All these issues for a few extra horses/less CO2s. The M112 would probably have been a more satisfactory engine by all accounts.

Anyway, perhaps not as catastrophic as I first thought. Read somewhere (can't find the link now) that it should be a 16 hour job tops to remedy this and should be doable at an indie for under £1500 all in parts+labour. Which is a lot, but not enough to write off a 100k car with these troubles.

Presumably though as the wear starts on this timing gear the engine isn't running optimum timing for potentially a few 10,000s of miles before it finally gets bad enough to trigger the CEL so you are going to be running at sub-optimal efficiency for performance/MPG for a while potentially.

 

[Bellow]

It's not ideal to have these defects on pretty fundamental bits of drivetrain. You'd think it would have shown up during testing really.

I think they rush them into production too soon. With so much of the early development being done via computer simulations, they must be losing out on 'miles under the wheels'.

Presumably though as the wear starts on this timing gear the engine isn't running optimum timing for potentially a few 10,000s of miles before it finally gets bad enough to trigger the CEL so you are going to be running at sub-optimal efficiency for performance/MPG for a while potentially.

Good that you've found a solution.
With something wearing in the manner of those photos, I'd be thinking of sooner rather than later for the repair. A broken tooth from a sprocket can do quite a bit of damage if it gets caught up in something else. That, and you get the benefit of the repair sooner, read: peace of mind.

 

[clk208]

I think they rush them into production too soon. With so much of the early development being done via computer simulations, they must be losing out on 'miles under the wheels'.

Certainly seems to be the case with the engine issues reported on pretty much the entire range of recent MB engines from 4-cyl diesels to V8 petrols.

I guess as time goes on the computer simulations will get better at identifying failures. Or maybe it's a cynical exercise to encourage people to switch their cars sooner.

Good that you've found a solution.
With something wearing in the manner of those photos, I'd be thinking of sooner rather than later for the repair. A broken tooth from a sprocket can do quite a bit of damage if it gets caught up in something else. That, and you get the benefit of the repair sooner, read: peace of mind.

It would certainly be worth thinking about as a pre-emptive fix. As it's a known issue and cropping up on cars barely 5 years old, MB should really be issuing a recall for this but they must have calculated that it's not in their interests overall.

 

[Dieselman]

The engineers know how long the components will last, but are constrained by cost.

Years ago Ford used to build their diesel engines with a 100,000 mile expected life, Peugeot with 300,000 mile expected life. It wasn't hard to understand why Ford engines fell apart.

 

[clk208]

The engineers know how long the components will last, but are constrained by cost.

Years ago Ford used to build their diesel engines with a 100,000 mile expected life, Peugeot with 300,000 mile expected life. It wasn't hard to understand why Ford engines fell apart.

Yeah I guess this sort of built in obsolescence is engineered into all sorts of consumer goods.

However, this doesn't really explain MB repordedly fitting uprated balance shaft/timing gear on the later M272 engines. Seems to point towards the failures in pre-2008 cars being somewhat unexpected - that's why the lack of a recall seems a little harsh to me.

 

[Bellow]

It would certainly be worth thinking about as a pre-emptive fix. As it's a known issue and cropping up on cars barely 5 years old, MB should really be issuing a recall for this but they must have calculated that it's not in their interests overall.

Apologies. I confused you with the guy already experiencing this problem on his ML.
I see your point - just fix it at the first sign of failing. Has this become a regular enough occurence to alter secondhand prices re had remedial work done vs not had remedial work done? That's how it has gotten to be with the eralier smart fortwos - advertising the car with a rebuilt engine commands a higher price than one without a rebuild which is assumed will fail. Oh happy days!

 

[clk208]

Apologies. I confused you with the guy already experiencing this problem on his ML.
I see your point - just fix it at the first sign of failing. Has this become a regular enough occurence to alter secondhand prices re had remedial work done vs not had remedial work done? That's how it has gotten to be with the eralier smart fortwos - advertising the car with a rebuilt engine commands a higher price than one without a rebuild which is assumed will fail. Oh happy days!

No worries. I haven't seen any mention of this remedial engine work in any of the ads for the CLS I have read. The petrols for sale are mostly under 100k miles and I could see people being wary of mentioning it in an ad when it isn't a particularly well known problem in the UK at the moment - if yours is the only ad for a car with major engine remedial work it could have the effect of putting buyers off.

Agree as more of these failures happen though it may eventually be mentioned in ads and affect the used values accordingly based on whether the car has yet been repaired. Joy!

I will probably defer my purchase for a while anyway - I don't have any real need to change other than fancying something different and loving that CLS shape.