[Psychobiker]

Hi,

Firing up my 1990 3.9 V8. I suspect that noise is the cats...as is coming from under the car. What do you think?

 

[1st rover]

well u have some tapping in the motor... i did not hear the cats that well.
but just hang on till some one else replies..

 

[John C]

Hi,

Firing up my 1990 3.9 V8. I suspect that noise is the cats...as is coming from under the car. What do you think?


click!

L

Please reply ASAP

That's a UK spec Rangie, I don't think you have cats. Even if you did that does not sound like the cats, more like a tapping sound.

 

[Psychobiker]

exhaust leak? not coming from the engine, anyway

 

[CoachDitka]

Edit: After listening about 20 times to that video, I would have to hear another one from under the car that pans from side to side. Hard to tell if that noise is a tic-tic-tic like an exhaust leak, or a tap-tap-tap like a worn bearing. Connecting or main bear noise will seem to come from under the car, but not be associated with a particular side, like an exhaust leak. Not sure about the exhaust from that MY, but I would check the donuts.

-Coach

 

[OkieRover]

This is a fun and very cool way to diagnose!
Props to you on that.

Doesn't sound like my cat noise. If my camera ever comes back from the shop I'll post the same.
Sounds like it's from engine or maybe the exhaust.
And you checked the exhaust pipes? All of the pipe from the head back?
Any holes in there? Are they buttoned up good to the heads?
Replace the gasket between the head and the pipe. My buddies 91 has a high pitched tapping that is his failed exhaust gasket between the head and exhaust pipes. Wish I could record those sounds for you....

 

[Psychobiker]

Cool. Just put some more oil in, and there now seems to be a definite mechanical tapping from the driver's side cylinder bank....UGH!

 

[CoachDitka]

Tapping from one side is definitely better than tapping from underneath. Good possibility it is simply a stuck or partially collapsed lifter, which was what I was leaning toward before I noticed you said there was no noise from the top end. You MIGHT get lucky with some additive for unsticking hydraulic lifters. They contain solvents, so don't leave in there too long without changing oil. I would get a mechanics stethoscope, or just use some vacuum hose, and try and locate the exact area of the sound. Easy enough to pop off the valve cover and see what is what. Pray for a lifter or bent/broken rocker arm, as those are both first cheap and easy to replace!

-Coach

 

[Psychobiker]

or the whole thing may be a phut exhaust flange gasket!

L

 

[yieldsign2]

That sounds like my truck, I have a leaky flange gasket that is at the lower portion of the Y pipe where it joins the muffler pipe. It will sound the same if you have a manifold gasket leak. When the truck is cold, turn it on and put y our hand around each exhaust port on the engine and see if you feel puffing.

 

[Psychobiker]

I gathered as much. it is DEFINITELY coming from the join - time to have my friend make me a new set of manifolds and a 4" catless system to two Janspeed boxes - sound good?