OM603 Head removal related questions - PeachParts Mercedes-Benz Forum

87tdwagen · #1 12-05-2014, 10:51 AM

Dear all,
So I am embarking on a long delayed project to open up the OM603 to replace the head gasket due to the decade long oil leak by cyl #1. I will be doing more than just the gasket while at it, one of which is to replace a leaking corrugated union (the one above the turbo). Since this will require removal of the exhaust manifolds the question is:

Is this best done in the car (head attached) to gain any stability and or leverage on the manifold bolts or

Should I decouple the exhaust pipe connections and remove manifolds with head and then remove manifolds from head once outside of the engine bay?

Thoughts, experience?

ah-kay · #2 12-05-2014, 11:20 AM

I have done both. It is a pain to R&R the exhaust manifold flex connector (117-142-01-59 ) with the head on. The best is to lift the head together with the exhaust manifold. The head gasket set, if you are going to buy a set, comes with intake/exhaust manifolds gaskets. Have fun.

87tdwagen · #3 12-05-2014, 11:27 AM

Quote:

Originally Posted by ah-kay

I have done both. It is a pain to R&R the exhaust manifold flex connector (117-142-01-59 ) with the head on. The best is to lift the head together with the exhaust manifold. The head gasket set, if you are going to buy a set, comes with intake/exhaust manifolds gaskets. Have fun.

ah-kay,
Thanks for the advice, I'll try that out. According to the FSM I need to decouple the trans-exhaust mount, I assume this is to allow the exhaust pipe some wiggle room in order to detach the large flex connector from the turbo exhaust union. I have also read that the turbo oil drain pipe slips off.

Is there anything else that you would recommend removing from the exhaust side to facilitate the extraction with the head?

TIA

ah-kay · #4 12-05-2014, 12:25 PM

You need to remove 1 10mm bolt to loosen the turbo drain pipe from the mounting bracket. That is it. I did not remove the exhaust coupling. The bottom line is the area is tight, nuts may be seized, order of removal may make a difference. The 2 turbo brackets above the exhaust is a @#$%& to remove. You don't need to remove turbo either.

winmutt · #5 12-05-2014, 12:42 PM

I can definitely attest that drilling out the back manifold studs in situ is a PITA. The location of the failure indicates you possibly had an early 86 build?

87tdwagen · #6 12-05-2014, 01:15 PM

Quote:

Originally Posted by ah-kay

You need to remove 1 10mm bolt to loosen the turbo drain pipe from the mounting bracket. That is it. I did not remove the exhaust coupling.

ah-kay Thanks again,

So to clarify just that 10mm bolt and disconnecting the exhaust flange at the downpipe and the manifold assembly breaks free from the rest of the exhaust? to be pulled complete with head?

That is helpful rather than to break it down in car. Did you guys remove the (trap ox) replacement pipe (alum foil encased exhaust section) and if so are any gaskets involved that may need replacing?

winmutt, Still haven't started the project so no broken studs yet, and hoping to take my time with this effort to ensure as few headaches as possible, slow and steady.

Thanks for the advice, keep it coming the BTDT crowd, lessons learned, neat shortcuts. I've read the archives quite a bit, good advice there, but there is always more

ah-kay · #7 12-05-2014, 02:01 PM

I did not remove the exhaust flange. I don't think it is necessary. The 10mm bolt is to remove the right hand side turbo bracket. It is not rocket science. Just pain to get to or nuts, bolts seized after many many years.

sixto · #8 12-06-2014, 02:22 AM

I forget - if you leave the turbo in place when pulling the manifold with the head, does the oil supply have to come off? If so, mind the clamp holding the oil supply line either the bottom row of manifold studs or the water pump housing. Don't forget to detach the transmission dipstick from the head.

Sixto
MB-less

87tdwagen · #9 12-08-2014, 08:23 PM

I've read several opinions regarding whether or not to remove the Vacuum pump prior to removing the timing gear/chain. Something to do with the Vacuum pump driven cam lobe applying additional forces on the timing chain which would affect cam alignment at TDC.

What is your experience? Have you removed the Vacuum pump to remove the cylinder head or leave it in place? (BTW it is the update style already)

TIA

ah-kay · #10 12-08-2014, 09:34 PM

Quote:

Originally Posted by 87tdwagen

I've read several opinions regarding whether or not to remove the Vacuum pump prior to removing the timing gear/chain. ????
TIA

Why you need to remove the timing gear/chain? R&R head is not for the faint of heart.

It is better in general to remove the VP. I removed it to give better access to guide pins removal. Also strap the cam sprocket to the chain.

87tdwagen · #11 12-08-2014, 09:58 PM

Quote:

Originally Posted by ah-kay

Why you need to remove the timing gear/chain? R&R head is not for the faint of heart.

It is better in general to remove the VP. I removed it to give better access to guide pins removal. Also strap the cam sprocket to the chain.

Ah-kay,
Sorry I was not more specific. I intend to zip tie the chain to the sproket, but was curious as to whether removal of the vac pump would be beneficial, you mentioned that removing the vac pump allows for easier guide pin removal so I'll take the advice, thanks.

What are your thoughts on replacing the water pump as preventative maintenance? Or leave the original untouched, spins freely and shows no leaks, no pulley play?

ah-kay · #12 12-08-2014, 10:11 PM

Quote:

Originally Posted by 87tdwagen

What are your thoughts on replacing the water pump as preventative maintenance? Or leave the original untouched, spins freely and shows no leaks, no pulley play?

If it ain't broke, don't touch it! Unless the part is inside the engine or a pain to get to. However, it is only me as I use the cheapest parts to maintain my fleet. Any new parts, probably would out last a 25+ years old car.

It is your call at the end of the day.

sixto · #13 12-08-2014, 10:35 PM

I'd leave the vacuum pump and water pump in place while working on the head. If you're doing this for the first time, you don't need more variables. I don't know what pin removal method benefits from having the vacuum pump out of the way. I strongly recommend this kind of pin tool -

Sixto
MB-less

87tdwagen · #14 12-09-2014, 10:25 AM

Thanks guys
I also believe in the old if it ain't broke don't break it trying to fix it

so the water pump and vac pump will stay in place.

sixto, I have that same pin removal tool so hopefully no issue.
Regarding pin removal/installation, I think the removal part is clear, but cannot find any info on installation, do you just tap them back in? How do you know when you have reached the right depth?

TIA

ah-kay · #15 12-09-2014, 11:45 AM

You will be removing the radiator, pulley tensioner, shroud, fan anyway, so the VP is just another piece of 'in-the-way' $hit. Almost everything in front of the engine is coming out. You have the pin extractor which makes life a bit easier. I do not think you would like to hammer the lower pin back in with the VP 1/2" away. You can measure the upper pin and hammer it back to the same length. The lower pin just hammer it flush and a little more.

It is your car after all.