Exhaust manifold leak REALLY annoying me... - PeachParts Mercedes-Benz Forum

Tomguy · #1 03-08-2004, 02:13 PM

I want to know what the easiest way to fix my problem is:

My left (driver's) manifold is attatched with 6 studs/bolts instead of 8 - two of the studs snapped off and are inside the head, so I can't tighten them. The front port (not the rear, at least to my knowledge) leaks at the bottom (where the stud is missing)

Is there an EASY way to fix this (Shy of removing/drilling/tapping the head)? I've tried tightening the remaining 6 in different ways/patterns to (theoretically) get more pressure on the bottom of the front port, but I can still hear a ticking sound from the left side of the engine whenever I drive (and louder so when the hood is opened). I also think my manifold has a hairline fracture in it but I dont see carbon outside of it that would indicate a leak.

Should I grab the left head off the wreck in the junkyard? If I do, does the 450 from say '74 have lower compression than the '72 4.5, and, if so, is this due to a different head?

Tomguy · #2 03-08-2004, 02:24 PM

FYI: A quick drawing showing which 2 studs are snapped off inside the head

psfred · #3 03-08-2004, 03:21 PM

Probably no way to keep that from ticking, but I'd check the seal at the bottom of the header first -- they are also notorious for leaking a bit.

To repair you are going to have to get the studs out and new ones in. That manifold is way to flexible to seal without a stud on the bottom. Probably requires removal of the head, drilling the old studs out, and either putting in oversized thread/standard thread studs (any machine shop can make them for you) or helicoils and standard studs.

Peter

Tomguy · #4 03-08-2004, 03:44 PM

Peter: Seal at the bottom of the header is fine, no leaks. There is carbon around the bottom of the front port, signs of a leak.

I was afraid of that answer, which is why I want to know if heads from a '74 450SE are lower-compression than those from a '72 4.5