I keep getting this vibration at about 1500rpm. It is only rpm dependent and I feel it around my exhaust side of my engine. I feel it best with my had on my turbo compressor housing. The turbine isn't even spinning at that speed (I can see that).

I looked at my open timing belt cover and noticed that right at that speed I can see the timing belt flap a bit. I just put it in a year ago. It only has like an inch of play at the front (long) side (thats with the crank turned counterclockwise to make it taught--if you turn the other way it makes the belt slack) which is supposed to be at spec. I am running an Unorthodox Racing cam pulley.

Anyone else ever have this? Can the vibration be transmitted from somewhere else? Worn main or rod bearings? What do they do when they wear? I get no such vibration at higher rpms.


thanks

 

Re-adjust the tension on your timing belt. You should notice more performance with a properly tensioned belt.

 

I seem to experience something similar. Same engine and I have the same vibration issue but at around 2500-3000rpm. I've asked a friend about it and he also told me it had to do with the tensioner of the timing belt. He said something about the timing belt flap.

I don't have the open timing belt cover so I can't see it. I'm wondering if the fix can just be an adjustment. Although I'm at the point where I should change my timing belt anyways. Let me know if you find a fix.


[Modified by ten_30, 4:14 PM 6/14/2002]

 

Rocket, I plan to.

Hey, is there a way to get in there and ajust the belt without taking all the accessory belts off? What a pain in the ***. I never tried to JUST adjust one, only replace them. There is that little window cover on the bottom timing belt cover that comes off to get to the adjust bolt but how the hell do you get in there with a socket to loosen it??

 

untighten the tighten a bit and then turn the crank pulley counterclockwise then tighten the tensioner to spec.

 

If you have power steering you'll need to take the power steering pump off to be able to get a ratchet with a socket on the tensioner bolt (14mm).

Be careful to have the socket fully on the bolt before loosening. It's is to strip the
tensioner bolt.

 

I get this same goddamned vibration from 1200 to 1500.. what tools are required to tension the timing belt correctly, and how will I know when it's properly tensioned?!

 

i adjusted my belt again today but the play still seems to be about the same (bout an inch deflection which is apparently normal). I removed my unorthodox pulley and replaced the stock one. I hope this helps. Now i have to replace everything!

 

ttt

 

i bet the uo crank pulley had something to do with it also.

 

well, I ajusted my belt and replaced to the stock crank pulley. I still get a strange vibration at about 1700rpm. gets better as car warms up. seems to be coming from my exhaust manifold/turbo connection but I can't for the life of me, pinpoint it.

I can still see that at that same rpm range my timing belt flutters a bit then runs straight again as the rpms increase. Has anyone looked at their timing belt to see if it makes a slight fluttering at low rpms. seems like some resonance freq. it hits at that point or something. anyone with their timing belt top covers off, please look and see what goes on when you rev the engine up a bit.

thanks