300SDL Head Gasket Tear
 

Hi everyone:
Just found the portion of the head gasket that seals the timing case top to the head protruding out about 1/2" . Would never have notice except the car was spitting oil all over the ground, front of engine , my foot etc....
Will be pulling the no. 14 head and replacing ... once again exhaust gasket as I had just done to repair the leak in the flex tube / pipe.
I guess now is a good time to do valves, guides and seals and check mating surface for flatness.
Anything I am missing that should be done while I have the darn thing off?
Perhaps discard the no.14 head and hunt for a no.17?
Anyone have thoughts on a shop other than Metric doing the work -- like a well known local diesel machine shop here ---- is some magic at Metric?
I have some concerns about the head not knowing how many times it has been off and some probably unfounded fear about re- torquing this well known poor casting and then having a crack show up .... after all the work is complete.
Thanks,
C..

Rebuilding heads isnt too hard just need the right tools which include valve spring compressor, vacuum tester, straight edge, feeler gauge.

Aluminum heads should .003 or less when a straight edge is applied to the head surface. Check for cracks in your head by cleaning it throughly and inspecting closely.

You should buy new head bolts and measure the lower block with a straight edge to check for any warping.

Now would be a good time to do the timing chain since you have half of the motor apart.

I hope my local machine shop can do a good job for me. Just did the timing chain about 600 miles back, might do the oil pump chain while I'm there.
I will be replacing the chain guides and tensioner. Yes, I will be getting all new bolts , buying the bolt set.
I 'll have to read up on the specs for the deck- block to see what kind of measurement I need to get there. I didn't think of that.

That's the fundamental problem with "local shops". You "hope" that they honestly know the tolerances on the M/B and you "hope" that they actually can measure them. It's quite a bit of an effort when compared to a Chevy.

Many of us have been very disappointed with the capability of local shops. In my specific case, I pulled the head from the shop after it sat six weeks and sent it to Metric. Others were not so fortunate and found that the valve guides were way oversized and the engine consumed significant quantities of oil.

Do not believe any posts on this thread referring to how easy it is to rebuild these heads...........unless that individual owns a machine shop and has done 50 of them successfully.

A further example of this advice is the gross misstatement about checking the head for cracks. The only confirmed way to ensure the head is not cracked is to have a proper rig to pressure check it. "Cleaning it thoroughly and inspecting it closely" is not going to cut it.

I have access to a very good machine shop that does really good work and knows what their doing so i trust them.

These heads on these cars are not easy like a chevy but still a lot of precise careful work. They arent that bad.

By pressure washing and applying a special powder that sticks to areas in the head that are cracked.

I don't need anymore grief and agree with you regarding Metric. I probably would not be able to sleep at night if I allowed someone else to do the work.
I am perhaps overly concerned though, that this no. 14 head is Not worth the investment after all I have read here and also what Marshall Booth had compiled regarding failures of these heads over time.
I priced a new head from the MB dealer (just the casting I think) in the sixth revision - a no.20 - the cost was about what I paid for the car.
Perhaps I should just buy the later casting.
Thanks for your reply.

If you intend to keep the car, find a #17 (or later) casting and put the money into that. I would not spend any $$ on a #14 unless you intend to sell the car. The sixth revision of the 603 head is a #22 casting, btw.

Remember that the casting number (stamped into the side of the head, 603-016-22-01) is not the same as the part number you would order from the dealership (603-010-96-20, current wholesale approx $1700, current MBNA list $2140).

If you are short on $$ and your current head is flat, straight, crack-free, and otherwise seems ok... replace the valve stem seals with new OE, re-assemble it, and forget about it. The #14 could last a long time. The valves, guides, and seats rarely need replacement unless something is damaged. These aren't flimsy M103 (300E) heads, lol...

:euro:

Naturally, if you can find a later head, it's preferable to do so. This requires some patience, but, they are available. I've got a #22 sitting in the basement...........fully reconditioned at Metric.

If time is not available and the #14 must be sent to a machine shop, it's preferable to spend the additional shipping cost and send it to Metric. The cost to do the head is approximately the same as most local shops that you'll find. If a local shop can do it significantly cheaper...........there's a reason for that.

Dave , thanks for the info.
A good friend in the Mercedes repair business explained a similar situation where I could just run the no. 14 head and at most have the head resurfaced
by our local machine shop and replace the stem seals. However , it seems to me that if the head is not flat then I might have more issues and perhaps should look for a later casting.

I did follow the progression of part numbers and recalled that I thought there was a number 22 head. Just didn't strike me that the casting numbers were different than the P/N , should have been obvious I guess with the same last 2 digits on each revision.

Thanks,
Chuck

Totally agree , I appreciate the response. Yes , you do get ... exactly ... what you pay for. Knowledge is value, and specialized knowledge is more valuable.

BTW , is your no.22 a spare for your fleet of SDL's or a pending project or just cluttering up your basement ?;)