I acquired this car with 200,000 miles on the odometer; it's generally in
great shape and has been well cared for. However, the previous owner sold it
because it was losing coolant internally (as opposed to a radiator leak).
The other day, it started smoke/steaming out the tail pipe, and losing
coolant very rapidly - I'd have to add a quart or two every time I took it
out. My understanding is that it is either a cracked block, or a blown head
gasket. If it is the latter, I am told I could probably do the disassembly
and reassembly myself - I'd send the head off to be machined at a shop. Any
suggestions or warnings as to which it might be (gasket or block) and the
advisability of doing everything but the machining myself? Also, anybody
know where I might get a good (English language) shop manual? Thanks.
With that engine it's very unlikely that it's a head gasket. It almost
certainly a cracked head. I have a friend with two '87 300SDL's. They have
the same engine as your car. I've helped replace heads on both of those cars.
Thankfully, the new heads have been redesigned and are more resistant to
thermal stress. By the way, the new bare head is $1,500 with valve guides but
no valves. If you can do the work yourself, you're looking at a $2,000 repair.
I can recommend a good machinist which you will need to lapp your old valves
to your new nead and switch over the other parts. Welding these old cracked
heads is a pointless exercise as they never last very long after they are
The problem is either the head gasket and / or the aluminum cylinder
head. The block is very unlikely. These engines are known to break head
gaskets and / or crack their aluminum heads when overheated.
I can e-mail you directly a couple of pictures of a cracked head if you
Thanks for all your help and suggestions. I am prepared to replace the head
(and gasket), and won't drive the car until I do so. Anybody know where I
can get the best deal on a head, and an English language shop manual?
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