Help, rumbling vibration, thrust bearing?

[Matty104 0]

hey guys

Heres the scoop, (after searching and coming up with not enough info)

e30 , m20 325i, manual

i did my water pump, and cambelt last night, torqued everything back up to spec etc, so was all fine after that,

today after work I go for a little open road drive then head back home.pull into the drive way and the car starts vibrating slightly with the rev's between 1000 and 1500 rpm.

the clutch release bearing makes a clunking noise when released , so my theroy is it could be that.

BUT the clutch and p plate and bearing were brand new with oem parts in febuary, so could there any reason for it failing so early , could it just be "one of those things" or will it be something else?

cheers

Matt

[Matty104 0]

anyone have an idea?

drove 300km yesterday , its a little bit worse, ie rumbling from 1000 to 2000 rpm now, It couldnt be a misfire? as it only does it through that rev range.

[williams 0]

sounds like an air leak, what else did you strip off-rocker cover?

[Matty104 0]

No nothing around the rocker cover area, just waterpump , dizzy , cambelt and pullys etc, and did an oil service at the same time,

Would an air leak would cause the idle to be irratic (sp) on start up?

And if it was to be an air leak why would it be only doing it at a certian rpm?, i have sprayed "start ya bastard" around air hoses etc and cant seem to get any fluctuations out of it

[320guy 0]

The thrust / throwout bearing will only rumble / make noise when you have your foot on the clutch.

[Guest FrantiC]

driveshaft bearings / prop shaft coupling.

or diff has come loose.

[Carl 3]

driveshaft bearings / prop shaft coupling.

or diff has come loose.

Also check your engine/gbox mounts haven't given up

[Matty104 0]

I had a look at the engine and gearbox mounts and they appear to be fine,

the vibration hasnt come back today ( yet), went to see my mecanic mate, he said to change the plugs and leads and distributer cap as it could be a slight miss , leads appear to be fine, and have swaped my cap for my parts one which to my surprise looks brand spanking new,

tomorrow I will do plugs and injector cleaner and top up the tank with 98 octane, and clean the airflow meter and icv with airflow cleaner,

should add if i haven mentioned it already that it makes this vibration while the car is sitting still as well as moving , so shouldnt be the hanger bearing or guibo.

[Guest FrantiC]

98 octane sucks in an old engine..

Stick to 91, or 95. Even there, there is barely any difference. I think 95 gets a tad more k's per tank but not really any noticeble power increase. 98 just isn't worth it, doesn't do anything for a 20 year old motor.

[Matty104 0]

Ok so ive had a think and ive come up with a few ideas of whats different compaired to usual.

My oil pressure switch apears to be leaking oil, (could that be causing a vacuum leak?) the oil tin light stays on for about 20seconds on cold startup, and today when turning a corner the light flashed ,

could it be the oil i used i got recomended to use 25w/70 comp 50 plus could it be to thick or thin ( not to clued up on oil viscositys) causing oil starvation?

Sorry about all the random questions guys, i just have no idea where to go from here with trying to sort it out.

Matt

[BMWTouring 20]

oil pressure switch wont cause a vacuum leak, that oil sounds a tad thick to me for an e30..

not to ask stupid questions or anything but you have got your cam timing right?

and is there plenty of oil in there? because with thick oils they usually get higher oil pressure as opposed to thinner oils which provide less oil pressure, so your oil light coming on while driving is a bit concerning.

if you get time, feel free to drop into work im at Hamilton Automotive and i can have a quick look for you if you wish.

Cheers.

[Matty104 0]

oil pressure switch wont cause a vacuum leak, that oil sounds a tad thick to me for an e30..

not to ask stupid questions or anything but you have got your cam timing right?

and is there plenty of oil in there? because with thick oils they usually get higher oil pressure as opposed to thinner oils which provide less oil pressure, so your oil light coming on while driving is a bit concerning.

if you get time, feel free to drop into work im at Hamilton Automotive and i can have a quick look for you if you wish.

Cheers.

yes the cam timing is right , i cranked the crank and cam andund 10 or 15 times befor i put it back to togeather and the lined up perfect,

And yes pleanty of oil,,

hopfully i can get off work early a day this week and take it for a drive till it starts vibrating and then i will drop in and see you mate, what was your name again? ( im no good with names, in one ear and out the other)

on a side note, the battery is pretty screwed and will be getting replaced after payday , probly will not contribute it the problem , but its the thought that counts

[BMWTouring 20]

No worries, just come in and ask for Aidan.