New idler pulley - does this need to be worn in?

[serth]

Evening all,

Had a new idler pulley fitted to my car today, and I've noticed a lot more vibration through the wheel and seats, and since then I've noticed a rattling coming from the manifold region. Now I understand that the vibration may be due to fully polybushed front and rear suspension, and that the top engine mount has just been done up by air gun instead of by hand (which I used to have done until today).
It could also be worth noting that the engine was lifted from its top drivers side mount by jacking it up with a block of wood under the sump.

Is the pulley likely to vibrate for a while until it becomes bedded in?
Is a manifold gasket likely at fault for the tapping noise etc?

Cheers

 

[quest63]

I'm no expert but 100% sure a new idler should absolutely not be causing any noise or need bedding in. something is seriously amiss.

I'm assuming you mean the auxiliary belt idler? not the cam belt tensioner?

Rattling from the exhaust manifold region?

Is this while driving only or also when stationary?

 

[serth]

Yes, I mean the aux belt idler, not touched cambelt!

The rattle/tapping noise seems to be coming from top of the rear of the engine where my 4-2-1 manifold is attached.

The only things that have changed on my car since this morning when it was working OK are when it was jacked up at the garage (one jack under drivers side, one jack under engine sump), top engine mount fully removed and the engine was pumped up a couple of inches using the jack to aid access to the idler.

Old idler removed, new idler fitted, belt slipped back on, mount re-attached and car ready to use. Straight away i felt much more vibration through the wheel and assumed that the pulley would need bedding in, but obviously not.

My thinking is that, because the engine mount was always tightened with hand tools and not electrical/air tools, that once the engine mount had been re-fitted with the airgun, it was tighter, therefore there was less tollerance for absorbance of vibration?
Either that, or the act of lifting the engine without removing the manifold has pulled on the exhaust system and created/worsened an air leak, which is creating the tapping noise.

And maybe the engine movement had affected the lower torsion bar/mount as i know this stops vibrations quite a bit?

A little stumped until i get under the car tomorrow and have a look, but I don't really want to drive it until i get it fixed.

 

[quest63]

I think its definitely possible the exhaust could have got disturbed particularly where the manifold meets the exhaust under the car. I also agree some small exhaust leaks can sound like a tapping.

Possibly a drive shaft problem?

I suppose its possible its a prob with the lower gearbox torsion mount but I think the rubber in it would have had to have been falling apart.

Is the vibration when stationary or when driving or both?

 

[748]

I would go back to the garage that did the job and ask them to have a look :roll:

 

[serth]

I had a thought whilst trying to sleep last night, went out this morning and checked it out, and what I suspected was correct.

The fella that jacked up the car obviously didn't see the lower strut brace, and as a result, this is slightly bent and touching the bottom of the sump, causing the vibrations through the steering wheel and chassis.

This is annoying as it's already my 2nd strut brace, but at the same time, the garage was a mates and they only charged me £10 to change this pulley as i couldn't get any of my sockets down the side of the engine (so kind of as a favour to me). So I'd feel pretty rotten taking the car back and asking for them to repair the damage.

I guess it's one of those things - always mod and repair your own car, and if your paying not much, it could reflect a less careful job

Will have a feel for the exhaust gasket to see if it's leaking today and if so, will replace as necessary.

Cheers for the help

 

[748]

Yeah, looks like one of them to take on the chin and mark it down to experience :roll:
At least you know what the problem is.

 

[Ziggy]

mmm jacking up on the sump ? wtf ? Just take the lower strut brace off and bend it back into shape and refit.

 

[The Arch Bishop]

Reading the original past, the engine was jacked up on the sump to raise it on the mount and help access, not the whole car.