r&r intake and exhaust manifolds. 85 300SD

[blackestate]

When replacing the glow plugs I noticed oil at the side of the engine, after looking further it appears that the intake manifold is loose.
I have a gasket but how do I get them off? any special tools, or tips.

Looks like they are bolted in the center? and how many bolts

Thanks

[kerry]

Loose intake or exhaust manifolds are not going to cause oil leaks. Have you looked for other sources for the oil?

[Brian Carlton]

If you must remove the manifolds, you're going to need to address the turbo first. Either the bracket below the turbo to the block has to come off (a real PITA) or the turbo must come off the exhaust manifold (a real PITA).

So, pick your poison on that deal. Both manifolds come off and are installed together on the same gasket.

As Kerry mentioned, the manifold is not causing your oil leak. The valve cover is usually the culprit.

[vwbuge]

Not an absolutely horrific job, I've done worse. It is time consuming. There are quite a few bolts hidden under there. I think they are 17mm. Just feel around in there and try to snug them up.

17mm, 13mm, and 10mm sockets and wrenches and a flatblade screwdriver are about all you need to do it. Only takes about an hour to R&R once you have done it a few times.

[charmalu]

Be careful of the turbo oil supply pipe you don`t bend it. One end hooks to the back side of oil filter, might need to loosen it.
There are 7 nuts that hold the manifolds on, I think it is recommended to replace them with new ones.
Removing the manifolds with the turbo attached is heavy and awkard, but you can do it. but easier than trying to remove the turbo first. tried that once and gave up.

About 2/3 way through the project you will ask your self, "Now why am I taking this thing off?"

Charlie

[blackestate]

ok, never having done much work on this car, and it is my 1st MB. Where could the oil be coming from?
I read the post about the oil drain from the turbo? the supply pipe? the oil is all over the engine area. And appears to be pushing up from below the valve cover.
I was assuming that it was the blow by that is pushed back into the intake. The car does not use much oil, Just what it leaks is all over the place. I even have a film on the inside of the windows from the air coming through the heater.

Thanks

[Brian Carlton]

Originally Posted by blackestate

ok, never having done much work on this car, and it is my 1st MB. Where could the oil be coming from?
I read the post about the oil drain from the turbo? the supply pipe? the oil is all over the engine area. And appears to be pushing up from below the valve cover.
I was assuming that it was the blow by that is pushed back into the intake. The car does not use much oil, Just what it leaks is all over the place. I even have a film on the inside of the windows from the air coming through the heater.

Thanks

When was the last time you had the valve cover off..........and adjusted the valves?

If it's not a favorable answer, that's the first thing you should do.........and replace the gasket in the process. There are four nuts and they should be tightened with a torque wrench to 11 ft.-lbs. It tends to leak when you guess............

[t walgamuth]

that manifold gasket is metal surfaced both sides, so I would try just tightening it first. removing it all on a turbo engine is a lot of work.

Tom W

[blackestate]

What should the manifold be tightened to? I will tighten the manifold, do the valves, replace the gasket and tighten that to 11ft-lb and see what happens.

[bulletproofair]

Is the manifold loose to the point of you being able to physically move it? Or do you THINK its loose because you see oil? As others have stated, the oil is from the valve cover gasket it seems. In this case, unless you can physically move the intake manifold, your manifold probably isn't loose.

You can reach a few nuts to tighten down the manifolds without removing anything, but unless you know for a fact that the manifold is loose, it most likely isn't and they probably don't need addressing....unless the previous owner installed a new gasket there and didn't tighten everything up, in which case, I don't think the car would run very good. If they weren't too loose to the point of affecting engine operation or showing obvious leaks (which may not be possible), there could be small air leaks from the manifolds you could hear or feel. These are my opinions, and only you know if your manifold is loose. Just don't assume it's loose because of an oil leak.

Go ahead and replace the valve cover gasket. Do the valves while you're under there. It won't take long and its easy to do. Make sure to clean it up well. After you take care of this, you will definitely know where the oil was coming from.

Good Luck!

[blackestate]

The manifold seems to move. Also when revving the engine and letting it go to idle quickly, I get a shot of smoke out of the front. EGR, or manifold? it is coming from down in that area somewhere.

[blackestate]

This was a bigger job than I thought. I started this morning, and did the valve adjustment. Then I put the cover back on and decided that I would tighten the manifold as it was loose.
After all of this I now have the manifolds off, and the trap oxidizer. What a pain in the.....

Anyway, When I assemble this, what is the proper way, and what can I do about removing the trap oxidizer.

Thanks
Doug

[Brian Carlton]

Originally Posted by blackestate

and what can I do about removing the trap oxidizer.

Return to dealer and get a brand new exhaust and possibly a new turbo as well..........depending on condition.........all free, of course.

[Jeremy5848]

Originally Posted by Brian Carlton

Return to dealer and get a brand new exhaust and possibly a new turbo as well..........depending on condition.........all free, of course.

If the '85 300SD has a 617 engine, the recall does not apply -- you're thinking of your 603, Brian. And if it is a 603, why is he doing a valve adjust?

Jeremy