strange exhaust clearance problem on '92 240

[Jeff Olsen]

Basically, my exhaust pipe is bonking against the "cross member" of the
"frame" right near the catalytic converter. It first did it with the
engine under heavy load, when I took my foot off the gas going over a
mountain pass. Now it does it any time you take your foot off at any
speed over maybe 50 mph. When the tranny is in reverse, the engine of
course torques over a little and it (the exhaust) then is pushed
constantly against the cross member and there's a nasty vibration that you
can feel.

One of the motor mounts, and the tranny mount are new and just checked
out as "good". The exhaust hangers all seem to be there. I replaced the
header pipe a few months ago and at that time had to mess with the
"L" bracket up near the oil pan/header pipe area that bolts the
header to the engine block. However, everything has been fine for months
since then. So I guess the question is, what changed??

I have gotten under there and pried things around. I thought I could just
loosen the bolts on the "L" bracket, pry the exhaust pipe down, and
re-tighted the bolts to get more clearance, but the engine, tranny,
exhaust, and driveline are all "sprung" together and it does not appear
that that will work.

Anyway... any ideas?

-jeff

 

[volvowrench]

Basically, my exhaust pipe is bonking against the "cross member" of the
"frame" right near the catalytic converter. It first did it with the
engine under heavy load, when I took my foot off the gas going over a
mountain pass. Now it does it any time you take your foot off at any
speed over maybe 50 mph. When the tranny is in reverse, the engine of
course torques over a little and it (the exhaust) then is pushed
constantly against the cross member and there's a nasty vibration that you
can feel.

One of the motor mounts, and the tranny mount are new and just checked
out as "good". The exhaust hangers all seem to be there. I replaced the
header pipe a few months ago and at that time had to mess with the
"L" bracket up near the oil pan/header pipe area that bolts the
header to the engine block. However, everything has been fine for months
since then. So I guess the question is, what changed??

I have gotten under there and pried things around. I thought I could just
loosen the bolts on the "L" bracket, pry the exhaust pipe down, and
re-tighted the bolts to get more clearance, but the engine, tranny,
exhaust, and driveline are all "sprung" together and it does not appear
that that will work.

Anyway... any ideas?

-jeff

If the trans to headpipe bracket isn't broken, make sure you haven't
backed into something and bent the tailpipe section. If it's bent it
makes the noises you describe.

Bob

 

[Guest]

I have exactly the same problem you describe, but on my '89 240 wagon....
It's been off-and-on for the last few months, and I've fixed it twice (and
about to do it a 3rd time) by loostening the bracket, then levering the
'pipe away from the frame before tightening the bracket clamp again. Nothing
looks defective, just no clearance! Still, this is a quick/cheap fix, even
if temporary.....

m9876c at yahoo dot com

 

[Jeff Olsen]

Thanks for the reply!

Well, I tried that but I kind of gave up when I realized the whole thing,
engine, tranny, exhaust, driveline, etc was all sprung (IE, on
hangers) and when I levered the exhaust I was moving ALL of that stuff
too. So I was worried about preloading the motor mounts or something.

Maybe i'll get under there and pry harder.

-jeff

 

[Jon Dough]

I just re-read my message, and I may have mislead you... I loostened the
CLAMP, not the actual bracket! This gave me a little more leeway in prying
the pipe away from the frame. Then retightened the clamp before removing my
prybar. Initially I had tried just prying the pipe, but as you have noted,
it simply moves, then comes back!