603 Head Gasket Replacement? - PeachParts Mercedes-Benz Forum

bikpedlr · #1 01-02-2011, 07:41 AM

I own an '86' 300SDL with a 603 engine (603 018 14 01). I have started getting a puff of steam (not smoke) as I pull away from stop light/signs in the last week (loss of coolant, and undo pressure in coolant system also). I'm an old school hotroder restorer out the 60's and reasonably knowledgeable, a good friend form the Houston MB community whom I trust says I've got a head gasket replacement in the near future. I need to know what I'm up against here both from a parts and materials standpoint, as well as time and labor allocation. There is about 225K on the car, and it has served me well for a couple of years now. Are there "kits" you can buy that have all the parts I need to do the project? Are there other things I should do/check while at it? Special tools that without which are make or break for this job? Manuals, video's, DVD's that walk me through the project? ANY insights are deeply appreciated, thank you

Stretch · #2 01-02-2011, 08:45 AM

I'm sure there will be many more of us here to give you some tips and help - but I'd first be thinking about a leak down test to make sure the problem you have is the one you think you have.

GregMN · #3 01-02-2011, 09:05 AM

When I first did the same job, the first, and best, advice I got was:

Get the Factory Service Manual first. Then you can check the advice you get against that. You will get very good advice from most forum members. You can find the FSM on CD for about $20.

layback40 · #4 01-02-2011, 09:43 AM

Quote:

Originally Posted by GregMN

When I first did the same job, the first, and best, advice I got was:

Get the Factory Service Manual first. Then you can check the advice you get against that. You will get very good advice from most forum members. You can find the FSM on CD for about $20.

I think there is even an online one you can access.
The head tensioning is an interesting procedure. The alloy makes some interesting noises as its squashed down.

R Leo · #5 01-02-2011, 09:51 AM

With residual cooling system pressure, on a 603 you are most likely looking at much more than a head gasket. Head castings with the number 014 are prone to cracking when overheated and the symptoms are just as you describe. Head replacement is usually reqd.

Another typical problem with 603 engines is failure of the head gasket between the timing chain gallery and #1 cylinder. In that failure, engine lube oil is pumped into the #1 cyl. Massive clouds of oil smoke and sometimes lube oil coming out of the tailpipe but no loss of coolant or residual cooling system pressure.

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Either way, you're pulling the head. And about the only special tool I can think of that you'd need (provided that you already have a decent compliment of metrics, etc) would be the special 'triple square' socket for the head bolts.

Definitely read the FSM's procedures before digging into or letting anyone else dig into that engine. If you need the specific procedures, PM me and I'll get them to you in PDF.

mplafleur · #6 01-02-2011, 07:29 PM

It's unlikely that it's just a head gasket.

To do this, the factory service manual is a must. You can get a DVD or maybe an online version, but the paper version is what I like best.

The triple square socket is needed for head bolts and if you replace the timing chain, you'll need a crimping tool.

04 Diesel · #7 01-02-2011, 09:43 PM

If you are lossing coolant, you have a bad headgasket or a cracked head.

R Leo · #8 01-03-2011, 09:51 AM

Quote:

Originally Posted by mplafleur

if you replace the timing chain, you'll need a crimping tool.

Not essential as the ends of the pins can be peened over.

W124 E300D · #9 01-03-2011, 01:29 PM

Quote:

Originally Posted by R Leo

With residual cooling system pressure, on a 603 you are most likely looking at much more than a head gasket. Head castings with the number 014 are prone to cracking when overheated and the symptoms are just as you describe. Head replacement is usually reqd.

Another typical problem with 603 engines is failure of the head gasket between the timing chain gallery and #1 cylinder. In that failure, engine lube oil is pumped into the #1 cyl. Massive clouds of oil smoke and sometimes lube oil coming out of the tailpipe but no loss of coolant or residual cooling system pressure.

I run a "603 engine" it is one of the best and most reliable car engines anyone, including MB, have ever made.

I am talking about the venerable naturally aspirated 603.912 of course, but it is still a "603".

It is imperative that people get their facts right, which always means avoiding all abbreviations and short-cuts, of which this "603 engine" is a classic example.

mplafleur · #10 01-03-2011, 02:10 PM

Quote:

Originally Posted by R Leo

Not essential as the ends of the pins can be peened over.

Not "essential", but recommended. Especially for peace of mind.

babymog · #11 01-03-2011, 08:09 PM

Quote:

Originally Posted by W124 E300D

I run a "603 engine" it is one of the best and most reliable car engines anyone, including MB, have ever made.

I am talking about the venerable naturally aspirated 603.912 of course, but it is still a "603".

It is imperative that people get their facts right, which always means avoiding all abbreviations and short-cuts, of which this "603 engine" is a classic example.

Unless of course your 603na has the #10 casting or earlier head, ... then it has a high potential for cracks / failure.