85 300TD blown headgasket? - Page 3 - PeachParts Mercedes-Benz Forum

PowerstrokeJoe · #31 04-23-2012, 06:43 PM

In theory you should remove them in the reverse order of how they came out. The cam towers are held in by the head bolts as well as one nut on each tower. Remember these are TTY bolts so check them for stretch. They really should be replaced but they are pricey. The IP doesn't need to be locked but if you move the engine over you may get to re time it. Before you remove the cam chain you will need to take a paint pen and mark the chain position on the cam sprocket.

macdoe · #32 04-23-2012, 06:46 PM

Thanks for the reply...I have purchased brand new headbolts for this job. So then once the cam tower bolts come out then that single bolt from each tower will hold the cam in place? In other words camshaft removal is not necessary?

macdoe · #33 04-23-2012, 06:49 PM

I have moved the engine to the correct place and zip tied the chain to the sprocket(again)...also marked it with paint marker (again). Does the timing chain tensioner need to come out? I got the top guide pin out and removed that top plastic guide. I have loosened the bolt that holds the sprocket in place but have not removed it yet.

ROLLGUY · #34 04-23-2012, 07:02 PM

As long as you don't turn the crank while the head is off, there is no need to mark anything. The cam gear is keyed, so it will only go on one way. If you are replacing valve seals, I would suggest that you remove the cam followers and cam & towers assembly. You need to remove the cam gear and the upper chain guide in order to get the head off. I usually tie a wire to the chain and have someone hold it up while the head is lifted, and then tie it off somewhere to hold if from falling inside. If the chain does fall inside, it is not that big of a deal. The lower chain guides prevent the chain from jumping the gear. I usually remove the entire manifolds/turbo as a unit, as the head is heavy enough! Yes the chain tensioner has to come out. The cap and spring come out first, and then the two bolts holding the tensioner body. For installation, the plunger only goes one direction, so it gets inserted after the chain and gears are installed.

macdoe · #35 04-24-2012, 12:37 PM

Does the big aluminum guide that the tensioner pushes against need to be removed as well?

We have the cap and spring out and the bolts loose on the body of the tensioner but it seems to be stuck. The spring looks very much worn on a couple of spots almost like it has been rubbing on one side. The lining on the big aluminum guide looks worn down quite a bit, and I wonder if that could account for the numerous timing chain replacements that this car has had according to the records it came with.

macdoe · #36 04-24-2012, 03:23 PM

I don't think that the large tensioner guide needs to come out....but just as you said above the rocker arms HAVE to come off to get a few headbolts unthreaded all the way on the pass side. Does that sound right?

ROLLGUY · #37 04-24-2012, 04:38 PM

The chain guide on the left side (facing the engine) does NOT have to come out. The entire tensioner needs to be removed (cap and spring first, body second).

whunter · #38 04-24-2012, 04:57 PM

Quote:

Originally Posted by macdoe

I don't think that the large tensioner guide needs to come out....but just as you said above the rocker arms HAVE to come off to get a few headbolts unthreaded all the way on the pass side. Does that sound right?

Diesel cylinder head issues thread

om615, 616, and 617 head bolt torque sequence

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macdoe · #39 04-25-2012, 01:41 AM

We got it out. I think that something is wrong with the #2 cylinder...the prechamber looks encrusted with carbon built up on top of a light rust colored substance. I have scraped it off somewhat now but have taken some pictures right after the removal of the head.

The head gasket seems brittle and looks like it may have been leaking in several spots but I am not sure.

macdoe · #40 04-25-2012, 01:46 AM

some more pictures...

macdoe · #41 04-25-2012, 01:58 AM

here are some more pictures...we got it out with the manifolds and turbo in place. Was there supposed to be any special instructions for the sls drive sprocket inside the head...I took it out....not sure if I had to but it seemed like it was necessary.

macdoe · #42 04-25-2012, 02:04 AM

Here are some of the ports intake and exhaust.

macdoe · #43 04-25-2012, 02:10 AM

some of the exhaust manifold.... The pod in the last picture...is this the wastegate actuator, and it looks like it has been leaking alot of oil out where it is clean...it came off this way....there is a slot and it appears that is where the oil is leaking from.

macdoe · #44 04-25-2012, 02:21 AM

Some pictures of the cylinders. they look great to me. These are not very good pictures and we will get some better ones tomorrow. #2 is the one with streaks of oil .....they wiped off very clean and virtually no ridge at the top. I wonder if some sort of oil would be good to let soak in those bores.

macdoe · #45 04-25-2012, 03:10 AM

What size of tap is required to clean the threads for the head bolts and what should be used to clean the surfaces on the block and head. Wire brush on a drill...or is that too abrasive? Thanks