vibration noise on cold start up

[jonny_g]

hi all

for the last month ive been having a vibration noise which can only be heard from inside the car and it only happens when it gets quite cold (less than 9deg). it happens after about 15-30sec after starting my car in 1st the morning. i can feel the vibration on the footrest next to the clutch pedal but it is definitely coming from the engine bay and not any loose trim. once the engine reaches operating temp or after bout 5-10 mins driving, the noise disappears.

when i give it a bit of throttle, the noise does change pitch. if i rotate the steering on full lock from 1 side to the other, this sometimes stops the noise or irnterrupts it until i reach full lock; then starts again.

something else that ive noticed is that before the vibration occurs, there is a sort of squealing noise - not familiar slipping belt kind, more like a badly oiled bearing squeal if you catch my drift. ive also noticed that when ive been havin this problem, the idle revs are a little erratic with the needle fluctating between about 750 and 900 roughly.

i had the same problem last year; once the weather warms up, it goes. just want to find out what it could be and sort it

cheers

jonny

 

[jonny_g]

any suggestions, fred edde etc?

 

[jonny_g]

?

 

[Fred@BTM]

hard to say but i would first check the dog bone and then the aux belt and its ancillaries

 

[jonny_g]

whats the dog bone? is it a mount?

 

[jonny_g]

was out at the car again and did a few random things to see if anything happens so here's what i did

- engaging and disengaging the clutch = no effect on noise
- engaging clutch and keeping it pushed in whilst selecting gears = no effect
- giving it a bit of throttle = changes pitch of noise. if i go up to 4k or so, it seems to
disappear, either that or th vibration frequency just becomes too dificult to
distinguish
- turning the steering wheel rapidly from left full lock to right and vice versa = this gets rid of the noise until i stop, at which point it then comes back

on the basis of this, could i rule out a mount and maybe be looking at a steering rack problem?

my PAS is electric btw so not entirely sure if it has an alternator driven pulley?

hopefully this info will help somebody of greater mechanical knowledge point me in the right direction

cheers

jonny

 

[jonny_g]

anyone?

 

[jonny_g]

up

 

[jonny_g]

ttt

 

[Josh@Renparts]

the electric steering isn't powered on the aux belt, its a manual rack with a powered column, sometimes the motors make a bit of noise but not known bad vibration, with it been a diesel the engine does tend to produce a lot of vibration so just check all the mounts are in good order.

 

[jonny_g]

ok

so what does run from the alternator then? it it just the single crankshaft pulley to recharge the battery?

 

[jonny_g]

ok

so what does run from the alternator then? it it just the single crankshaft pulley to recharge the battery?

.

 

[richy22]

Are you sure its coming from the engine?? My exhaust shield vibrates like f**k on start up. And disappears after a while. It also does it on full lock on mine.

 

[jonny_g]

dont think so

but out of interest, how far along the underside is the heat shield?

 

[jonny_g]

bump

 

[jonny_g]

still causing grief and am waiting to get it seen by mechanic but bit difficult with holidays etc. any sugestions (edde etc) would be great thanks

 

[bhall809]

my car got simular trouble except it vibrates like hell when over 60 any ideas

 

[jonny_g]

that could be wheels misalligned or wheel bearing amongst other things

 

[jonny_g]

bump
still having trouble

 

[edde]

I'd check the engine mount but more likly its an aux belt or tensioner though they do make this problem appear mines had it for ages and Its not caused any trouble

 

[jonny_g]

changed the coolant at the weekend and it hasnt done it since??

coincidental?

 

[edde]

changed the coolant at the weekend and it hasnt done it since??

coincidental?

Shouldn't be

 

[jonny_g]

whys that?

 

[jonny_g]

so noise is now gone completely. thankfully!

coolant chenge has definitely done the trick therefore can i assume that the noise was possibly a grumbling water pump?

if so, should i replace it or just get it done next tme the cambelt is due changing?
thanks

j