help on pulling head to replace a head gasket - PeachParts Mercedes-Benz Forum

blount1966 · #1 12-30-2009, 10:06 AM

any suggestion on pulling a head to replace a head gasket? just bought a 1987 300sdl with head gasket blown. thanks for any info.

JEBalles · #2 12-30-2009, 10:15 AM

Head's probably cracked/warped. It'd be cheaper/easier to just replace the whole engine probably.

If you want to pull and possibly replace the head, are you looking for the whole procedure?

Junkman · #3 12-30-2009, 11:02 AM

Quote:

Originally Posted by JEBalles

Head's probably cracked/warped. It'd be cheaper/easier to just replace the whole engine probably.

If you want to pull and possibly replace the head, are you looking for the whole procedure?

Why is replacing the head more work than an engine swap? Why do you suggest an engine without more diagnosis? I haven't done either on these cars and am needing more information leading to your conclusion.

Crazy_Nate · #4 12-30-2009, 12:27 PM

Two questions:

1. Was the engine overheated?
2. What head casting do you have?

Quote:

Originally Posted by Jeremy5848

The head number is cast in the aluminum. It is on the left (driver's) side of the head and almost exactly under the air pipe that crosses over the valve cover. You don't need a mirror but a bright flashlight will help and hope that there's not too much oil and dirt. You have to look between the injector hard lines and see a little bit of the number, then shift your view and see a little bit more. The number should be 603 016 xx 01 where xx is the head revision number. AFAIK, the choices for "xx" are 14, 17, 20, and 22. The "603" means it was first used in the 603 engine; the "016" means it is part of the air intake system, and the "xx" means the revision number. I forget what the final 01 is and it could be some other number too.

Jeremy

The #14 heads are susceptible to cracking if overheated - if this is the case, it's not simply a question of replacing the head gasket. If the previous owner hasn't divulged all of the information, and you were just told it 'needs a headgasket' - it might need a bit more work than you were expecting. If you plan on doing the job, it should be checked for flatness and pressure tested at a machine shop.

mplafleur · #5 12-30-2009, 01:02 PM

I just did this last month. It's not bad to just pull the head.

First and most important:

Hand turn engine to TDC (leave it there and NEVER move it!)

Let's see, remove these...

Fan and cowling (no need to remove radiator)
Fan belt and belt tensioner
Vacuum pump
Crossover intake pipe
EGR valve body and related stuff
Injector lines (leave injection pump in place!)
Intake manifold
Glow plug wires, sensor wires
Timing chain tensioner (the whole thing, not just the center!)
Fuel line to and from the injection pump
Bracket holding the spin-on filter (pull the whole thing off to the side)
Aluminum heat shield between turbo and coolant expansion tank
Unbolt the turbo bracket from the head (I left the turbo in place)
Valve cover

Mark the cam sprocket and chain. (you don't have to, but it's easier if you do)
Unbolt cam sprocket and gently tap it off the cam. Once it is off, you can remove the sprocket and then what I did is tie-wrap the chain to the banana shaped chain tensioner rail to the left of the chain. If the chain falls in, it can be pulled back up, it's not going to loose it's timing.

There is a timing chain guide in the head that needs to be removed by removing two pins in the head. A bolt threaded in to the pins with some washers/bolts (with a hole larger than the pin). I used to use the bolt method, but now use a pin puller tool.

Like one of these:

http://cgi.ebay.com/ebaymotors/Mercedes-Benz-Chain-Guide-Rail-Pin-Puller-Remover-Tool_W0QQcmdZViewItemQQhashZitem56385c4f0cQQitemZ370312761100QQptZMotorsQ5fAutomotiveQ5fTools

You will have to untie the chain to get the guide rail out of the head.

Now the camshaft can be removed. Unscrew bearing cap bolts 1, 5 and 6. Now loosen bearing cap bolts 2, 3, 4, and 7 one turn each until counterpreassure is reduced. Remove cam and now the head bolts can be removed in the opposite order of tightening. So loosen them from the two ends moving inward to the center of the head. Don't forget to remove the two allen head cap bolts inside the head next to the timing chain.

Use two intake manifold bolts and bolt the bracket that was on the manifold for lifting the engine back onto the head.

I hope I didn't forget anything, but the head can now be removed.

GregMN · #6 12-30-2009, 01:40 PM

If you know what you are doing: one day off, one day on.

Get a factory service manual.

http://www.peachparts.com/shopforum/showthread.php?t=259773 some photos in that thread may be useful

The previous post suggested removing a few things that I do not think need to be removed:
Vacuum pump
fuel lines to and from the IP

I zip tied the chain to the cam sprocket and it passed through the head just fine.

If you drop anything down the timing chain passage to the oil pan, you have to get it back out, which may mean removing the oil pan. If not, this may happen to you: http://www.peachparts.com/shopforum/showthread.php?t=265948

mplafleur · #7 12-30-2009, 07:30 PM

I removed the vacuum pump so that the timing chain would not move as the roller bearing is pressing against the timing device. I don't know why they didn't design it so that at TDC, the roller would be at a valley so that it wouldn't disturb the timing.

I would take no chance that the timing chain move. Once it does, you're screwed. Removing the vacuum pump is easy.

Keeping the sprocket on the chain only gets in my way, it's up to the DIYer to determine what's comfortable for them.

I didn't mark the chain/sprocket or tie the sprocket to the chain. I just tried the sprocket a few times in different positions until it matched up with the cam at TDC.

babyjames · #8 12-30-2009, 11:44 PM

Totally agree. Don't mess with the radiator or the turbocharger. The procedure outlined in the WIS makes this job MUCH more difficult than it needs to be.

You'll have to remove the windshield washer reservoir, too.

Jay

blount1966 · #9 01-07-2010, 11:19 AM

Quote:

Originally Posted by mplafleur

I just did this last month. It's not bad to just pull the head.

First and most important:

Hand turn engine to TDC (leave it there and NEVER move it!)

Let's see, remove these...

Fan and cowling (no need to remove radiator)
Fan belt and belt tensioner
Vacuum pump
Crossover intake pipe
EGR valve body and related stuff
Injector lines (leave injection pump in place!)
Intake manifold
Glow plug wires, sensor wires
Timing chain tensioner (the whole thing, not just the center!)
Fuel line to and from the injection pump
Bracket holding the spin-on filter (pull the whole thing off to the side)
Aluminum heat shield between turbo and coolant expansion tank
Unbolt the turbo bracket from the head (I left the turbo in place)
Valve cover

Mark the cam sprocket and chain. (you don't have to, but it's easier if you do)
Unbolt cam sprocket and gently tap it off the cam. Once it is off, you can remove the sprocket and then what I did is tie-wrap the chain to the banana shaped chain tensioner rail to the left of the chain. If the chain falls in, it can be pulled back up, it's not going to loose it's timing.

There is a timing chain guide in the head that needs to be removed by removing two pins in the head. A bolt threaded in to the pins with some washers/bolts (with a hole larger than the pin). I used to use the bolt method, but now use a pin puller tool.

Like one of these:

http://cgi.ebay.com/ebaymotors/Mercedes-Benz-Chain-Guide-Rail-Pin-Puller-Remover-Tool_W0QQcmdZViewItemQQhashZitem56385c4f0cQQitemZ370312761100QQptZMotorsQ5fAutomotiveQ5fTools

You will have to untie the chain to get the guide rail out of the head.

Now the camshaft can be removed. Unscrew bearing cap bolts 1, 5 and 6. Now loosen bearing cap bolts 2, 3, 4, and 7 one turn each until counterpreassure is reduced. Remove cam and now the head bolts can be removed in the opposite order of tightening. So loosen them from the two ends moving inward to the center of the head. Don't forget to remove the two allen head cap bolts inside the head next to the timing chain.

Use two intake manifold bolts and bolt the bracket that was on the manifold for lifting the engine back onto the head.

I hope I didn't forget anything, but the head can now be removed.

thank you for all the info pulled the hed last night and all went fine. your info was better then alldata.

blount1966 · #10 01-07-2010, 11:24 AM

Quote:

Originally Posted by Crazy_Nate

Two questions:

1. Was the engine overheated?
2. What head casting do you have?

The #14 heads are susceptible to cracking if overheated - if this is the case, it's not simply a question of replacing the head gasket. If the previous owner hasn't divulged all of the information, and you were just told it 'needs a headgasket' - it might need a bit more work than you were expecting. If you plan on doing the job, it should be checked for flatness and pressure tested at a machine shop.

ok got the head pulled and it was very visible, three crackes

. any body no what all heads will fit on this? or have a good head for sale ?
Thanks

mplafleur · #11 01-07-2010, 12:12 PM

Quote:

Originally Posted by blount1966

thank you for all the info pulled the hed last night and all went fine. your info was better then alldata.

You are welcome. I'm glad I was able to help.

I don't remember what head casting number you have, #14, 17, or 22. But if it is anything other than a number 14, you might be able to get it fixed.

My #22 has a small leak, but I don't want to take it off yet.

blount1966 · #12 01-07-2010, 08:58 PM

Quote:

Originally Posted by mplafleur

You are welcome. I'm glad I was able to help.

I don't remember what head casting number you have, #14, 17, or 22. But if it is anything other than a number 14, you might be able to get it fixed.

My #22 has a small leak, but I don't want to take it off yet.

unfortunatly i have the #14 head. are the others interchangeable? and are the other heads cast or aluimiumn. I am new to these cars but i am learning alot fast.

barry123400 · #13 01-07-2010, 10:00 PM

There is no cast iron version of your head. I have to wonder myself if one could have been manufactured and made to work if mercedes tried. Usually a number 17 0r 22 head is located if possible for a replacement.

They can be cracked too just less likely. The cheapest source might be a pick and pull if you have any. Or advertise in our parts wanted forum. Ocassionally available on ebay used as well.

You will have to check in the archives but above a certain casting number there is machine work involved I think. Plus you have to have the newer style hard injection lines. The number fouteen head has gone a tremendous distance on some cars. I think it is just more fragile than the later head numbers.

These engines do not want even one good overheating. So make sure all components in the cooling system are in really good shape after you install a replacement head. It would be a shame to lose another head to an old radiator hose for example.

C Sean Watts · #14 01-08-2010, 10:11 AM

Quote:

Originally Posted by JEBalles

Head's probably cracked/warped.

Not entirely true, the gasket was redesigned both independently of and along with the head in order to fix an oil leak failure in front of #1 cylinder. It's relatively quick to rule out a cracked head in these engines - once they are off.

Quote:

Originally Posted by JEBalles

It'd be cheaper/easier to just replace the whole engine probably.

For an OM603 the whole engine is MUCH more costly than even a new head, the exception being finding one in a junk yard where the owners don't quite know what they have. OM617s are 'cheap' and plentiful in comparison.

Factory procedure tends to be lengthy.