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Discussion Starter · #1 ·
I'm starting to run out of ideas here on my girlfriend's 2000 GT 5-speed.

It's got a rattle that sort of corresponds with the engine speed, but is most noticeable at lower RPMs in higher gears (from around 1800-3000). Idle is quiet and you can barely hear anything when you rev it.

Things I've done/checked so far:

Took to a good mechanic, he said it was piston slap and to try some thicker oil, but also said it wasn't anything to really worry about, these are just noisy engines.

Took it to a good transmission shop, they said transmission was fine and that the noise is coming from somewhere else in the engine bay, possibly the engine.

Removed upper exhaust manifold heat shield (was rusting and cracking)... no effect

Replaced Transmission Oil (Mobile 1 full synthetic)... no effect

Replaced Motor Oil (Quaker State 10W-40)... no effect

Took head cover off and checked valve clearances... all were in spec (higher end of the specs though)

Also, when I had the cover off, on the underside of it I noticed where a plate of metal was bent right under the oil cap and looked like it could be hitting the intake cam. Looks like somebody pushed the funnel in to hard and bent it down. It's pretty flimsy as it is. I was convinced that was the problem since she said she first noticed it after I changed her oil 1.5 weeks ago. But the noise was still there after I put it all back together.

I also bled the coolant 1.5 weeks ago when I changed her oil since her heater wasn't working while idling (it did fix the heater problem). I read on here where a guy was getting a rattle due to air trapped in his coolant, so I bled it again and got quite a bit more air out of it by massaging the hoses. I'm pretty sure I got it all out this time, but it didn't change the noise any. Gonna keep an eye on the level though and see how that goes.

While I was bleeding it I found a small vacuum hose with a check valve on it that was disconnected from the air box, I hooked it back up but that didn't help any either.

I'm running out of ideas. It might be the timing chain tensioner, but from everything I've read it makes most of it's noise at idle and this is quiet at idle.
 

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Sounds like my problem, i changed everything in the engine, before i finally was getting ready to change the block, and took the intake manifold off, turned it upside down to lay it on the workbench and noticed a rattle coming from it, there is some sort of divider plate in the manifold that goes right above the ports on the engine side inside of it, it had broken loose and was rattling inside of the intake, i took the throttle body off, and had to break the plastic peice out peice by peice, the noise is gone, i had had several mechanics and engine builders look at it because it had me confused, i had everything diagnosed from a broken valve spring to piston slap (which is what everyone said) mine had gotten progressively worse and i had given up and was replacing the block when i found this, check it out it could be the same on yours. Toyota even said it was a rod bearing and wanted to do a full teardown, check it out.
 

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bailcel said:
Sounds like my problem, i changed everything in the engine, before i finally was getting ready to change the block, and took the intake manifold off, turned it upside down to lay it on the workbench and noticed a rattle coming from it, there is some sort of divider plate in the manifold that goes right above the ports on the engine side inside of it, it had broken loose and was rattling inside of the intake, i took the throttle body off, and had to break the plastic peice out peice by peice, the noise is gone, i had had several mechanics and engine builders look at it because it had me confused, i had everything diagnosed from a broken valve spring to piston slap (which is what everyone said) mine had gotten progressively worse and i had given up and was replacing the block when i found this, check it out it could be the same on yours. Toyota even said it was a rod bearing and wanted to do a full teardown, check it out.

Can you describe the location of this a little better? How hard is it to get to? I haven't looked to see how to go about taking the intake manifold off.

Also, did yours rattle at idle or not? Describe the rattle a little more too if you could.

Thanks man
 

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Mine would rattle from about 2000 -3500 at first then started from 2000 till redline, when driving it sounded like marbles bouncing around in the engine, it made the same noises a knocking rod would have, when the engine was warm it would go away for a few minutes and then come right back, i have had a lot of experience with engines, i thought it was a rod/wristpin/or piston slap, and the experts did too, it sounds like a knock or "tick".

Location: if you look inside the throttle body it would be on the top right of the intake manifold, there is a chamber in that area, and the plate separates it, i think it is there as a baffle to limit noise inside the plastic manifold. It is completely inside the mainfold, if it is already fallen off, you may be able to see it laying in the bottom of the intake manifold, if it is loose and you took the intake off, you could tap it with a screwdriver and see if it rattles.
 

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XtCamZ said:
Also, when I had the cover off, on the underside of it I noticed where a plate of metal was bent right under the oil cap and looked like it could be hitting the intake cam. Looks like somebody pushed the funnel in to hard and bent it down. It's pretty flimsy as it is. I was convinced that was the problem since she said she first noticed it after I changed her oil 1.5 weeks ago.
Ho my god I had this trouble too 2 years ago... and you know what? it appear just after a visit a the toyota dealership for an oil change...

After that further oil change have been done by.... me!

:laugh:
 

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if you have the engine running. remove power to the sparkplugs one by one. while its removed try reving the engine a little. if the rattle goes away, you probably spun a rod bearing.

i know this, because i just recently spun bearings one and four.
 
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