2000 GT Engine Noise

[ConeKiller]

Have 2000 GT...

At around 3000-4500 rpm the engine picks up a (for lack of better word) knocking sound. But it does not sound like pre-ignition. Sound more like the the car needs another court of oil in the valve train.

Car sounds fine at idle. Compression is good. Valve clearance is good. Change plugs, no CEL, reset computer, same deal... Noise is only there under load.

Any ideas... My thoughts are A) Exhaust leak, B) Timing Chain tensioner (thus noisy timing chain)

Any help, I would appreciate it... Thanks!

[GTS LAID]

i get the same sound in my car too ... but mine is a GTS... it comes on most consistantly when i let go of the gas.. and some days it does it more than others... i thought it might have something to do with the drivetrain.. but you might be right about the oil thing.

[Griffin]

If its only under light to medium load I'd say carbon buildup / glowing carbon deposits. Try switching to premium and see if it goes away / gets better.

Griffin

[po9i]

i've never had that problem in my 00 auto GT

[Nightchild]

ConeKiler:
Read my post (http://www.newcelica.org/forums/showthread.php?s=&threadid=29309) from a few minutes ago, there's a good chance you have the same problem I did. If so they may have to replace your whole transmission. Good luck either way though.

[ConeKiller]

The diff problem you mentioned on your car is not the problem. This noise kicks in even at a stop in neutral, effectivly taking the whole drivetrain out of the loop...

This noise is coming from the top side of the head... Going to check valve clearances in the morning and see what's up there. I had my mechanic look at it, and he ruled out just about everything but that.

We'll see in the morning.

[GTS LAID]

oh then its definately not the same as my problem... i posted in the other thread that nightchild mentioned.. basically mine is much more similar to his problem.

[SiNisTeR 892]

I just replyed to someone who has the same incident. I have the exact same problem as you, it doesnt make a noise till bout 3-4 grand rpm, it rattles or knocks. It is from the drivetrain its one of your lifters/rockerarms, most likely one of them just got knocked outta place so it cant open up one of the valves it just rattles. i took my car in a couple days ago so ill post back to tell you more info.

[autxr]

Rick-

If it isn't a rod knock (not sure why you would have rod knock on your car...) then I vote for a loose bolt.

My GTS had an obvious vibration (about 2500 rpm) that was reproduced as you state. I finally tracked it down with a stethescope and found out one of the monting bolts for the AC compressor has worked loose.

The bolt was partially obscured by one of the AC lines, so it didn't fall out of the hole, it just rattled.

You might also want to check your motor mounts if you haven't already.

Scott

[DaksGT]

Its the belt tensioner I believe, it makes that kind of dieselish type noise

[SiNisTeR 892]

I went to the mechanic to check to see whats up with my car. He took off the valve cover and everything looked completely fine...so i guess it is not the lifters/rockerarms... get back to me if you find so more info thanks

[Phaseshift]

I think it's you have a hamster wheel stuck in your engine. Replace the hamster with a rat and it should solve the problem.
:thumbup:

[gavin]

same problem.. car at dealer, they told me they tested everything that could affect the problem, they are nuts.. they checked out the ECU and made sure that it worked.. and checked that the fuel ratios were good.. then said it was fine.. thanks for the info, im going to print some posts and get them to check the things you've said :)
-gavin
(i hear a lot about belt tensioners going bad... and this could cause a deiselish noise? (cause thats what it sounds like) most prominent at 2750 RPM :(

[gavin]

also, do yours get worse after 4000?? cause mine only exsists between 2500 and 3500 under light load not heavy