chattering noise from 2.9L

[86broncII]

have a chattering noise form a 2.9L engine while under load, i have no cel or oil pressure light that comes on. had oil pressure checked with mechanical gauge and was all good. this does not seem to effect performance or fuel mileage. I appreciate any 2 cents that comes my way.

 

[adsm08]

Kind of a hollow rattley sound under specific loads?

 

[86broncII]

yes, usually during moderate to heavy acceleration. BTW, i had the converters blown through and the transmission was recently rebuilt. this noise was heard before all this as well.

 

[adsm08]

Well the reason I asked if because I have an 88 5-speed with all new exhaust and I have what I think is the same noise.

Not a clue what it is, but now I can pretty safely rule out the tranny and the exhaust.

 

[Shran]

I am pretty sure you are hearing "pinging" if it's the same thing as adsm describes. I get the same noise in my '96 Ranger, my '86 F150, and it happened a lot in my old Nova and my previous '88 Ranger.

Try running a higher grade of gas on your next tank and report back. Doing that helped mine a LOT, almost to where it goes away completely.

 

[86broncII]

will do, thanks! i will report back!!!

 

[adsm08]

I am pretty sure you are hearing "pinging" if it's the same thing as adsm describes. I get the same noise in my '96 Ranger, my '86 F150, and it happened a lot in my old Nova and my previous '88 Ranger.

Try running a higher grade of gas on your next tank and report back. Doing that helped mine a LOT, almost to where it goes away completely.

The noise that I hear from mine isn't ping. My greatest fear is that it is actually piston slap.

 

[Shran]

The noise that I hear from mine isn't ping. My greatest fear is that it is actually piston slap.

Doubtful. Especially at operating temp under load. Piston slap generally occurs when the engine is cold and goes away gradually as the engine warms up. It's engineered into Gen III GM 60* V6's, the 3.1 in my old Malibu was pretty loud. I am pretty sure that an engine with any noticeable piston slap at operating temp would be so insanely worn out that it would have a serious lack of compression and a few other obvious issues.

 

[ldbill39]

Check your timing, especially since the weather is getting warmer. The noise under load should be pinging, and that can be caused by lower octane gas or the timing not done correctly. If you check the timing remember to pull the spout, the spout is located where the wiring goes through the intake it looks like a closed termination plug. Hope this helps.

 

[adsm08]

Doubtful.

Oh, I agree. That's just my worst case scenario.

 

[86broncII]

reporting back, the noise that I having, I believe is octane related. this vehicle has had same quality fuel (87 octane, same service station) for years, I went up to 89 octane with noticeable difference in the noise but it was still there. Over the weekend I switched to 91 octane and dont even hear the noise at all, so far (fingers crossed).