Bad vibration from under car when accelerating

[Marshy]

Let's be clear first off... this is not thrust arms.

I had to load the car up pretty fully with band gear this weekend, and encountered a problem that hasn't gone away when unloading the car again. Could be co-incidence with the heavy load, or not. I dunno.

Anyway, when I pull away or accelerate once on the move, I get a pretty bad vibration from under the car, sometimes accompanied by a knocking/ticking sound that rises with road speed, not revs. At constant speed it's absent, and it worst around the 50-60mph speed range.

So I'm thinking it's something driveshaft related, which may have been exacerbated by the heavy load on the rear of the car. What are the possible causes do you all think? Is my wallet going to regret this? Can I trust a local mechanic to do the right thing with driveshaft stuff, or should I take it to a stealer?

Thanks... (dreading the answers...)

[new540iowner]

I had the same problem about a year ago. When I pulled the drivehaft, I found the center support bearing material was torn and allowing the driveshaft to hit the outer bearing support. What caused this though was the staked U-joint. The driveshaft shop that replaced the U-joint said there was a slight snag in the U-joint's range of motion. Cost was about $220 for them to disassemble, replace the center support bearing (part supplied by me for about $30), replace the staked U-joint with a circlip held U-joint, reassemble, balance and paint.

[Unregistered]

I had a harsh vibration turned out to be the waterpump starting to go and the rad fan was wobiling, its an outside chance but very easy to cheque, just see if there is any play on the fan and water pump area, mine could move in and out almost half an inch.

[Chad535]

A bad engine fan can cause ugly vibrations too, I replaced it with a BMW original and that concluded a 1 year's episode.

[Marshy]

Thanks guys. Finally got to unload the car this morning, and the problem is now much less severe, though still present. That probably rules out water pump & fan, and the pump was replaced quite recently anyway.

[632 Regal]

guibo?

[Marshy]

Well I do wonder about the guibo too, given the pasting the autobox must have been giving it over the last year with my harsh 3rd into 4th shift issues. It'll be back to the shop this week, so we'll see what transpires.

May some higher entity have mercy on my wallet.

[Marshy]

Well, I guess I'm lucky on this one. Just had it looked at with a local specialist, and it's an obvious problem that I could have spotted myself: broken engine mount.

Could have been worse...

[tdgard]

I noticed a little quicker though--when the blade came off it made a nasty dent in the hood

[uk525isport]

I noticed a little quicker though--when the blade came off it made a nasty dent in the hood

that will explain why i have a dent on my hood from the inside and a new fan fitted!!!!!