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Oh great, a conflicting opinion from a reliable source!

Would any other videos help? I still haven't put the valve covers back on.

If I did a seafoam treatment would create enough smoke to have it come out of a leak if there was one? How does a mechanic do a smoke test?

harofreak00 wrote:Oh great, a conflicting opinion from a reliable source!

Would any other videos help? I still haven't put the valve covers back on.

If I did a seafoam treatment would create enough smoke to have it come out of a leak if there was one? How does a mechanic do a smoke test?

I was thinking the same thing. Brake clean makes smoke too and you wont need much. Is it louder in the back or the front? I would like a video like the first on posted but holding at a higher rpm like say 2500rpm.



Edit: another option would be to start tightening all exhaust bolts.

why would an exhaust leak get quieter as the car warms up? unless the idle is just lowering.

bonnevillain wrote:why would an exhaust leak get quieter as the car warms up? unless the idle is just lowering.

Due to expansion and contraction of the metal. The heat makes it expand and therefore seal up.

that is no exhaust leak to my ears

See if you can follow along with this video... its quite the trip!

I can't do much more running of the car without the valve covers, the manifolds are just covered in oil.

Wow! It is so hard to tell. It sure seems like its around that EGR or crossover, but it still does have that metal like tap in there.



Edit: Andrew have you played back the videos yourself? Does it sound more tickey (crisp) in the video compared to real life? It seems like it is to me?

Sounds like an exhaust leak to me. Now u have a video of it running. put the covers back on and do the same video. See if the volume changes. It would stand to reason if it is the engine it would be louder with the covers off and a least a little quieter with them on. Take it to Monro or Midas and have them do a free inspection of the exhaust system.

I still hear an exhaust leak... I could be wrong.. I wish I was closer Andrew..

This is Lifter Tick... Andrew does it sound like this?

Blownville wrote:Edit: Andrew have you played back the videos yourself? Does it sound more tickey (crisp) in the video compared to real life? It seems like it is to me?

Yes, MANY times. In real life, it sounds pretty darn close to how the video sounds. To me it sounds more like a PUFF rather than a metallic ting. I have searched high and low for an exhaust leak, but I can't find anything. I maybe tomorrow I'll take off the crossover and cut off the surround and see if there is a leak. There definately isn't a leak at the donut gasket.

Jrs3800 wrote:I still hear an exhaust leak... I could be wrong.. I wish I was closer Andrew..

This is Lifter Tick... Andrew does it sound like this?

Kinda? I'm really not sure. I just don't know why I can't narrow down what cylinder it is, if it is indeed a lifter.

seafoam should be able to tell you, i have a slight leak and i get a little smoke in the engine compartment from seafoam

Just for good measure I would wrench all exhaust bolts and use a mirror to try your best to see if those manifolds have any cracks. One thing to keep in mind with an exhaust leak is that a single cylinder will not have a constant tick it would be uneven. So your leak would be somewhere other than at the tube extending out of the head unless it's the whole mani loosened. Check your EGR and tube also cause we all know those things crack all too often.

Just brainstorming here...
Clean up all the oil from the manifolds(run for a while till smoke clears or burns-off) get some oil or hydro fluid down the inlet (vacuum line maybe?) while it's running and look for smoke coming from the exhaust seals? Disconnecting the fan too would help so it's not blowing air everywhere.

I just talked to my dad, showed him the video. He says 100% exhaust leak. He told me to go get a piece of 3' rubber tube to use as a stethoscope and try and track down the leak. I'll see what I can do tomorrow.

Does that EGR tube look cracked to anyone else?

Another thing to check, is there oil coming up to all the rockers? Is any one getting less oil volume than the others?

Sounds just like my 89 did when it was leaking at the crossover. I just tightened it and it went away. Check all the exhaust fittings and make sure they are tight, including the connection under the car by the firewall.

This sounds very familiar to me, Andrew, and not in a good way. When I bought my '95, I was so sure I had a lifter tick that I replaced all my lifters with a new set - no fix. My pushrods showed some scuffing on the top ends but nothing too bad. Could find nothing wrong with the rockers. Then, I removed the exhaust manifolds and sure enough, one was cracked and neither had gaskets. I replaced the manifold and the gaskets and - no fix. I have a mechanic's stethoscope but I was unable to isolate the tick to any one cylinder. That is a bad sign. It implies that the sound may be from deep inside - in my case, probably a loose piston pin. Mine was running (badly) with up to 20 degrees of timing retarded by the PCM attempting to stop the "detonation" reported by the knock sensors. I was able to work around the problem by replacing the knock sensors with a calibrated resistance load and running premium fuel, but with an L67, that approach would be likely to result in a perforated piston. You are gonna' need to find the source and fix it. I hope it turns out to be an exhaust leak. I had one on a Chevy 350 that sounded exactly like a lifter. Would not have believed it if I hadn't heard it myself.

bill buttermore wrote: I had one on a Chevy 350 that sounded exactly like a lifter. Would not have believed it if I hadn't heard it myself.

Bill: Do we agree that the noise sounds like it's in the valve train?

Question, Andrew: have you pulled the plugs for all cylinders? I'm kinda wondering now that since you haven't found anything in the valve train, a spark plug electrode might have broken off and dropped into a cylinder, and is rattling around inside there. This would also obviously account for the rough running you're experiencing.

This goes against my oft-stated principle of "simple things first," but weirder things have happened.

Yes, plugs were pulled yesterday (Bosch platinums) and replaced with Autolite 605's.