E30 Zone

well after a good year of replacing nearly everything, i have two problems left.

1) the car vibrates over 80mph, was origionally at 65mph but after prop, centre bearing guibo etc replace its loads better, what else can it be? nothing is loose or nothing showed up on mot etc. and the tyres/wheels are balanced

2) the fuel pump has started to buzz/vibrate the rear seat gently massages you and as some say its really nice id rather fix it? i replaced the tank about 6 months ago, all was good, but just started to buzz now?

i am sure you guys will know exactly what it is thanks

I don't know about your vibration possibly the centring guide on the output shaft of the gearbox (if it wasn't replaced)
The fuel pumps can get noisy with age and sometimes even different quality fuel can cause this, but there is no fix short of adding more soundproofing. There is definitely something amiss if the seat is vibrating. I'd say your pump is on the way out.

get your wheels balanced the that is ruled out as it can cause vibration

On my wife's car there was a vibration at 75 / 80 , balanced wheels had tracking checked and it was still there . This was the first e30 we had owned and the vibration was from the middle to the back . The car was due an mot so I thought they would find if something was worn out , Passed with no advisories . Prop , gilbo and center bearing next , prop was OK with white dots in line , gilbo was a bit iffy and center bearing felt a bit rough so both were replaced and the bearing loaded and I still had the vibration . At this point I had enough and felt happy that she would keep below 70 and let it be . Another set of wheels and tyres another mot and another straight pass and it was now vibrating at 65 /70 . I was jacking the car up to adjust the handbrake and on the second side I noticed the rear beam drop a lot more than the first side . When I pulled the bush out the center was separate from the rubber , new bush fitted and no more vibration .

if i "pursuade" the pump round clockwise a little the noise/vibration stops, but after so long of driving it restarts

thanks sanitroc1 sounds possible its the rear bushes there not in a1 condition ill change them next then as with mine i have changed everything you have already

anyone?

It wouldn't surprise me if the rubber O-ring around the fuel pump has hardened over time. That will allow the pump to vibrate and rattle in it's hole, transferring a lot of noise up and into the seat. For the sake of a few pence, it's worth changing that to get a tighter seal around the pump, which might solve your issue. If it doesn't, it's time for a new pump.

As for the vibration, start simple. Swap the wheels front to rear, and see if the vibration persists or changes somehow. If it doesn't, you'll have to check each suspension component, starting with the bushes.

thanks strangely enough i filled the tank up today and the noise has gone, its only happened since i swapped the tank, ive never put more than £15 in now i have £60 in :O ill check the rubber O-ring and perhaps just remove the pump and replace it, i would have thought it would slowly get lounder if it was failing rather than be quiet then sound like a wasp in my ear suddenly.