Update - Dealer
 

So the car came back from the dealer today. The tech who diagnosed the car is someone I know and I trust him, he's a solid guy.

They had the car for quite a while and went over the engine. Total bill was $600, which included 16 new plugs (at my request since they pulled them anyway for testing and my car is due to replace them). What they found was that it appears to be the valve guides leaking. They did compression tests and leak test. Also checked the PCV system and it was fine.

Here are the readings -

Cyl 1 - 150
Cyl 2 - 150
Cyl 3 - 140
Cyl 4 - 150
Cyl 5 - 140
Cyl 6 - 150
Cyl 7 - 160
Cyl 8 - 160

He also mentioned that there was some oil fouling on the plugs and that it appeared to be from one direction only.

So...appears to be valves (guides/seals).

My option now is to have the heads redone ($2500) and dealer says there may be potential for MB Canada help if the heads are sludged when they pull the valve covers. I'm not counting on it though, and I don't think the dealer is either, though they were optimistic about it.

If it is just the valves (guides/seals) then I can live with that. Given what I paid, I'm comfortable having the heads done if this fixes the problem.

Any other opinions?

TIA.

Well if your trust them, and it sounds like they did a lot of diagnostic work to arrive at that conclusion.

You shouldn't have replaced the spark plugs, now your new ones are just going to foul out.

They may get a bit fouled, but I plan on having the work done soon and I would think any oil will burn off once the heads are fixed? Good point though. :o

$2500? Get that in writing as that sounds like a VERY reasonable price for a two-head V-8 job, especially from a dealer. It's what my indie charges, and he's usually about $1K below the local dealers.

If the dealer thinks MB Canada might pitch in if they find sludge, I bet there really is a good chance they will. They deal with these problems all the time and have a good idea of what is going on with regards to goodwill. It's my experience with many MB out of warranty goodwill that MB Canada offers to split the bill with the customer. One exception seems to be the spring perches, as anyone I've known with the issue has had 100% of it covered. Seeing as you have a W210, you might want to dove into that as well as it looks like you're keeping her...

(Oh, and if you're going to have the heads done, don't delay, as the oil is going to destroy the cats, and then you're going to be out several thou more..)

$2,500 isn't bad at all, its not cheap but IMHO reasonable considering the job.

John - I should have been clearer, the service guy got me one quote from MB and one from a local indie shop they use for machine work. The $2500 is for the dealer to R&R the heads and the local indie shop to machine them. They've used the shop frequently and they stand behind their ability. The quote from MB's machine shop was significantly higher! :eek:

Yes, I do plan on moving forward on this quickly as I agree re: the cats fouling. O2 sensors as well.

The consumption has slowed considerably now that I am doing city driving. It really increases on highway trips, when I'm staying in the 3-4000 RPM range.

The perches were inspected at the dealer by the previous owner as per a tech bulletin of some sort (don't have the number handy). They were fine then. Probably not a bad idea to have them looked at again though...

Save your $2,500 bucks.

Get your upper valve cover gaskets replaced as their leaking oil can find it's way into the spark plugs.

Stop using ELF oil!

Move to something along the lines of a thicker Maxlife viscosity and drive the crap outta it.

www.bobistheoilguy.com

300B - I had a couple of techs check the valve cover gaskets. Both thought that the amount of oil present didn't account for the amount lost, or for the smoke in the exhaust (occasional puff of blue smoke when starting).

It's an interesting theory though. If it leaks and seeps into the spark plug area/well overnight, you'd see a puff at startup until it burns off and then nothing else.

Perhaps at highway speed, the leak increases under load and the oil drips off the engine onto the highway. Then when stopped/parked, the leaking essentially stops as well and you don't see any on the driveway. :confused:

Seems too good to be true.

You may have already grilled them on this - but WHY - does a 113 motor need a valve job at 144k km, under 100k miles. The predecessor 119 motor doesn't seem to ever need top end work.

The M112 series of motors don't have many if any top end problems and are a far more durable than it's predecessor.

deanyel - Yeah, I am worried about that as well. It seems far too early to have normal wear on this engine.

I can only guess that since this car went 17,000 Km between oil changes on conventional oil up to 90,000Km, the oil likely lost its ability to protect and lubricate properly towards the end of that interval - thus causing premature wear. Or causing sludge to buildup, causing the valves to leak.

Either way, I'm guessing a head job will cure either situation. Expensive though. All the techs I've spoken with say the same thing you guys are, M112/M113 have zero valve issues.

It's incredibly frustrating as there is apparently no easy answer, other than throwing a lot of money into it. :(

I am tempted to try a few runs of something like Auto RX to try and clean the engine out and see if that frees anything up/cleans sticking valves. Doing so would void any help from MB, but I think that is a long shot at best.

Then again, if I futz around with cleaners, oil changes, etc. and my cats end up getting fouled, I'll be out $2000 for a new set of cats.

Fun, fun, fun.

Going to sleep on it tonight and try and come up with a plan over the next few days. Any more suggestions are welcome.

If oil leaks into the spark plug hole nothing will happen, maybe a miss fire eventualy. That does not account for the amount of oil you are losing, the engine is burning it. A leak of that size would leave a puddle everywhere you parked.

My old Camry 2.2 had that problem, very similer set up to the M104 actualy, the spark plugs were at the bottom of a deep tube. I was always changing the gaskets to keep them from filling up with oil. Once the well filled up with oil and it sat and cooked for a few months it would skip, and you would have to change the wire. But we are not talking about a lot of oil, maybe a few OZ's.

IMHO you have two real options at this point. Get the work done, or trade the car in. Pretty much with the PO did and dumped the problem on you.

I'm sure the 112 series has a lot of fine features, and I agree that it doesn't seem to have many top end problems, but calling it more durable than the 104s/119s is a genuine knee slapper. This is the engine that has had thousands of botton end re-rings, or maybe it's tens of thousands, no way of knowing for sure. It is even now only 10 years old and it's been in more trouble than Mike Tyson. It was in court in a class action lawsuit for premature wear, oil sludging, oil consumption and "other internal defects" by 2001 - when it had been out for LESS THAN 4 YEARS. And MB didn't really contest the suit, couldn't, too much evidence against them, so they settled quickly. 104/119s are now 18 years old, top end work is rare, and bottom end work virtually non-existant. There is good reason for the premature death of the 112 series. You might want a do-over on this one.