Jump to content

Bizarre Noise at mid RPM


statikuz
 Share

Recommended Posts

I was driving around tonight and noticed AGAIN a funny noise my engine makes from 1000 to about 3000 RPM, it sounds almost like sticking a piece of paper in a fan, a whirring noise, but slow enough to make out individual "click click click click", but pretty darn fast. It goes faster as RPM goes up and disappears around 3000. Any ideas? I know the description's pretty vague. =)

Link to comment
Share on other sites

Well the problem is that it doesn't make the noise at idle, there has to be power to the engine for it to happen, which makes me think a clutch problem [which could be entirely off-base]. so yeah, the stethoscope method won't work I don't think. =) It does almost seem like its coming from the transmission or at least from the near side of the engine, but I'm not really sure.

Link to comment
Share on other sites

*clears throat*

Could it be detination? :takebow: Higher octane gas should clear this up. There's a thread on this exact sound, I know cuz I had the same noise. Thanks NPORA guys :clap:

Link to comment
Share on other sites

Y'kno, that could be it... I used to get the middle-grade gas but since the latest ripoff as far as gas prices go I went down to regular... that might be it. =) Thanks, we'll see next time I fill up.

Link to comment
Share on other sites

If its detonation, it'll be a dull pinging sound, particularly under load such as accelaration and climbing hills. Kinda odd that you would have it, but maybe it could be a tuning-related situation. I've always used 87 octane cheapie gas, and have had none of those issues. Another idea: with the price of fuel lately, you may consider picking up a case of cheap octane booster rather than actually buying the mid or up-grade gas. I've seen it at Walmart and such for under $2.00 a bottle.

Link to comment
Share on other sites

another thought along the pinging line is ignition timing, since one is the result of the other

 

ie the further advanced your timing is the easier an engine will ping under load, try knocking your timing back 5 degress. you get less mpg and less power but if you dont control pinging you will end up with big holes in your pistons :blink:

 

as stated above higher octane fuel helps HEAPs, my pathy has a carby motor and i run premium fuel to help stop pinging, dont get any other benefits like more power or mpg but the pinging is minimalised

Link to comment
Share on other sites

the further advanced your timing is the easier an engine will ping under load, try knocking your timing back 5 degress. you get less mpg and less power but if you dont control pinging you will end up with big holes in your pistons.

 

More like 2 degrees at a time. 5 degrees is a LOT, considering 12 degrees BTDC is reccommended. :)

 

I second the exhaust shield notion, go shake all of your shielding and see if anything's slightly loose. Mine were. I removed them all. :P

Link to comment
Share on other sites

D'oh, I was gonna suggest the exhaust too. Mine did it only in a certain rpm band as well, I think it was around 1500 up to 3000 or so. Guess it depends on the speed of your engine to get the right vibration going. It was a high pitched tin sounding vibration, and did get faster up until it died out. Crawled under with some cutters and pliers and all was good.

Link to comment
Share on other sites

:furious: I'm having this EXACT same problem at the moment with my '96 Ti (Australian name for LE). I got 3.3 V6. I've only had car for 2 months so don't know how long this has been happening before I got it.

Sorry I don't have an answer but I do have some observations which might narrow things down a bit...

 

1) Mine 'rattle' is (irritatingly) audible from 1300-1500 (ish) RPM in all gears. Less noticable in Park or Neutral.

 

2) I originally thought it was heat shielding but me and my mechanic friend stripped or tightened the shields with no difference.

 

3) Fuel's not the issue. I have dual-fuel. A 65-litre tank for Premium AND a 65-litre tank for Liquified Petroleum Gas (LPG). The noise is there whichever one I'm running on at the time.

 

4) Not detonation. Timing on a dual-fuel car's always tricky but mine's just been done. Besides, I know what detonation feels/sounds like.

 

5) Because it happens at rev range where gear shift often happens, I'm getting spooked that it may be related to my tranny or T-C, but it's only noise. It 'feels' sweet. I'm 90% sure it's in the exhaust.

 

6) I even thought it may be the honeycomb inside the cats, broken and rattling at the right harmonic freq (1300-1500 RPM) but the cats were checked and are fine.

 

I'm tempted to go new exhaust (headers etc) but it's a big investment and I'd like to know before I spend if it will fix the problem. I hope my information is helpful and if anyone gets a good result, please post it.

 

:sniff:

Link to comment
Share on other sites

Guest russellgrace72

:clap: This is my first post!

 

I'm having the same problem, I'm curious that it might be a worn timing chain hitting the side of the engine or cover. I was going to replace it just to see if that was the problem. I also considered adjusting the valve clearance. I will be stating work soon and will post anything I find. I've ruled out the exhaust shield over the headers. :)

 

Russell

Link to comment
Share on other sites

hydraulic lifters are not adjstable, only replaceable, when they get plugged with junk they dont pump up correctly. if you donr need a timing belt dont waste your time and money unless its due for one or youre really bored... spend your money on a lift or searching for the prob

Link to comment
Share on other sites

I have the same problem and I was thinking it is because of the manifold gasket. I had the classic manifold problem when I bought the truck and I'm not sure how long it was going on before I got it. I had the bolts and the gasket replaced, however the guy who fixed it told me that the new gasket melted and had to be replaced again. I'm thinking that the manifold is to warped. Is that a possibility?

 

It would give me a good reason to go get those thorley headers!

 

Any thoughts, ideas, suggestions???

Link to comment
Share on other sites

I have the same problem and I was thinking it is because of the manifold gasket. I had the classic manifold problem when I bought the truck and I'm not sure how long it was going on before I got it. I had the bolts and the gasket replaced, however the guy who fixed it told me that the new gasket melted and had to be replaced again. I'm thinking that the manifold is to warped. Is that a possibility?

 

It would give me a good reason to go get those thorley headers!

 

Any thoughts, ideas, suggestions???

I'd say its a good possibility. People say you can have the manifolds machined back to OEM specs, but what's the point really. It would probably cost the same as getting the headers. Wish I had gone that route vs. OEM repairs and waiting around to see when it fails again.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...