TheRook

I just switched my oil from castrol high mileage 10w30 to 10w40, and when I started my car there was this clacking/rattling noise. It's most apparent on cold start up, after it warms it goes away but i can still hear it slightly. My car is an 03 with 96k on it. I'm getting worried about driving it.

I've got some vids but the quality isn't great, all I have is my phone.

This is after a cold start, the noise is most noticeable at 26secs, after I rev it up you can hear it slightly when it drop back to idle.
http://youtu.be/H2X34-1DtIw

This is after i went for a 10-15min drive, it sounds more or less normal, I think
http://youtu.be/wzZCcX2DGlA

Kenshyn

I'm no expert here, but from what I've deduced after lurking for a while, I'm guessing it's the Timing Chain Tensioner.

FISH22

Yeah, thought I heard some TCT noise in there.

MR.T

Tensioner pulley on the drive belt.
Get a mech scope to verify. Place the end of the scope on the nut holding the pulley on and repeat you throttle blip.
You could momentarily run without the drivebelt to pinpoint that region, but i'm almost positive it's your pulley, so I'd just start there first.

You can buy that pulley separate from the tensioner and save some money. Also consider replacing your drive belt if its cracked, split or worn in any manner.

TheRook

Thanks a lot for the replies guys. I went ahead and sent a message to Billman for one of his TCTs. I'll go ahead and buy a mech scope to check out the tensioner pulley. Now if it is the tensioner pulley, would I have to buy just the pulley, or only the tensioner?

My mechanic also said that the loud valve train could be a sign of low oil pressure, what do you guys think of that? I was thinking of getting an oil pressure tester but not too sure how to use it.

Billman250

TCT noise is best recorded 6 feet away from car, hood closed.

I cant hear any there.

MR.T

you can just buy the pulley. i have an 03 and had the exact same sound at idle decent, after blipping the throttle. scared the hell out of me until i diagnosed it as just a pulley and not valvetrain.

be careful on sticking the scope in there while the motor's running. you can find a scope for cheap at harbor freight.

TheRook

Thanks Billman. Unfortunately I don't think the recorder on my phone would be able to capture anything from 6ft away with good quality, but I can try. I may still get a TCT later for assurance, piece of mind is always valuable.

MR.T, I'm going to get one tomorrow and check out the pulley, I'm hoping it's just that.

I'll keep everyone updated, thanks again.

TheRook

I bought a stethoscope from Harbor Freight today, and it seems like it is the tensioner pulley. The pulley sounded like something was loose and rolling around inside roughly. The tensioner also moved around very slightly while the car was on, but the pulley seemed off balance like it was oscillating, I had to put pressure onto the scope to keep it from tapping/bouncing against it. I checked out the idler pulley (smooth surface one?) to compare, and it sounded nothing like the tensioner pulley. I might try and start the car without the belt on too
Since I'm not a mechanic, I'm going to bring it to one so he can confirm the noise, and check the valve clearances (My valve train is still pretty loud around 2500-3200rpm).
I also scoped the TCT, it was pretty quiet. Injectors 1 and 4 were a little loud compared to 2 and 3, so I'm going to buy a cleaner for those.
I'm sure now it is the pulley, but I'm afraid to get my hopes up lol I'll update after the problem is solved.

TheRook

I'm at a loss now, I changed the tensioner pulley and the noise is still there. I ran the car without the belt and the noise was still there. I'm starting to think it's something internal. When I took it to my mechanic two weeks ago he checked the oil pressure and said everything is fine. The noise is getting louder on cold starts now. Can changing to a higher viscosity oil cause this??? I was thinking of changing back to 10w30 this weekend to see if it helps, any advice you guys can give me?