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Head Gasket Leak on MBZ 560SL

Our mechanic just told me that I have a head gasket leak on my 1988 Mercedes Benz. The car has 108,000 miles on it. I don’t
remember if I have ever had this problem before. Is this serious? Should I get it fixed right way or can it wait. They said that
it was a big job and the car would be in the shop for about a week. I was quoted $2000.

If correct, it is serious and should be fixed soon. This is the first time I’ve heard of an SL with head gasket problems, so I’m curious - how do they know? Oil or coolant leaking? Coolant in the oil? Bad compression?

How much do you trust this mechanic?

@Sadietoo I worked at a Benz dealer for many years and this was, though not common, not unheard of either.
I’ll assume someone performed a thorough diagnosis?
Since the intake manifold has to come off, I’d STRONGLY advise replacing both head gaskets at this time.
Have your mechanic replace the exhaust manifold gaskets while the head is on the bench.
Many guys replace headgaskets without bothering to remove the exhaust manifold.
I would also advise having someone VERY familiar with the 117 engine do it. There are MANY vacuum hoses, lines, wire looms, connectors, seals, holders, brackets, etc. that in all likelihood will NOT survive once they are disturbed and removed.
Do a COMPLETE reseal of the intake manifold. Replace the doughnuts that separate the upper and lower manifold.
Replace the thermostat. Inspect the water pump carefully.
If you’ve been using oil, now would be the time to replace valve stem seals.
After the repair, resist the temptation to mess with the on-off ratio, unless it’s absolutely necessary.

I hope your mechanic has good experience working on Benzes, because the 107 chassis isn’t a piece of cake to work on, and the 117 engine also isn’t a piece of cake to work on.

@db4690 - given all that, what do you think about the price? If anthing, $2,000 sounds low…

@texases IMO the mechanic might be quoting only one headgasket and a minimum of additional parts. These estimates need to be heavily “padded” to absorb unforeseen expenses (all the stuff I mentioned). If those things aren’t needed (although I can’t imagine they wouldn’t on a vintage car).

BTW here are my Chilton labor times. These are regular times, NOT severe.

Right side 16.3hrs
Left side 15hrs
Both sides 24.2hrs

@Sadietoo can you ask your mechanic what that estimate entails?
What parts are included?
How does it break down?
How much for labor?
How much for parts?

These were literally the top of the line, and deserve to be maintained accordingly.


@Sadietoo - note that you have what many consider the best SL of that body style, so it’s worth fixing it right.

Here’s a discussion of some of the issues with a 560SL head gasket job. As @db4690 said, that bid sounds light, I’d make sure your mechanic has done these before:

Thanks for all the information. I am contacting the mechanic to get more information from him and I am also taking it to the Dealer for a second opinion. I know the Dealer will quote much higher because of higher labor costs. I’m not sure how the problem was diagnosed. Last week I had it in for an oil change and this was a note on the invoice.

@Sadietoo I’m not badmouthing the dealer, but don’t be surprised if they’re not entirely eager to do the job. They’ll likely only have a few senior guys who would even be comfortable replacing the headgaskets and all that comes with it.

Until you find out the extent of the problem I’d avoid driving it, if possible. If coolant in getting in your oil it could ruin the engine, which then becomes BIG $.

@Sadietoo let me guess . . . the headgasket is leaking externally, trickling oil down the side of the block, correct?

Talked to the Mechanic and the head gasket leak (right side) was determined by a visual inspection, while they were doing the oil change. Talked to the Dealer and they said that it is not a very common problem, however, to bring it in and they will do a complete inspection for $230.00.
Most likely the Dealer thinks it is probably “the valve cover leaking down”. If it is a head gasket leak they always replace the two (as db4690 said), not one as the Mechanic indicated. So I won;t know for sure until sometime next week after the Dealer has looked at it.

@Sadietoo a leaking valve cover gasket is far more common on that engine.
Another possible fix, if it is indeed the headgasket leaking, is to retorque the head bolts.
Mind you, this isn’t really the proper repair.

I now wonder about your mechanic pushing cylinder head gaskets if it turns out just to be a valve cover gasket.

The Benz dealer…This could be one of those 100 post threads…

@texases while leaking valve cover gaskets are more common on that engine, leaking headgaskets do occasionally occur. Usually it’s not a fast leak, but more of a “seepage” issue.