Engine noise when cold?
Engine noise when cold?
Author
Discussion

_AJ_

Original Poster:

405 posts

227 months

Tuesday 11th December 2007
quotequote all
From a cold start, I've always had a bit of a knocking noise from the engine, that gradually dissapears once it's up to normal operating temps. It's mainly heard at lower revs when accelerating gently (as one does with a cold engine). I can't hear anything odd at idle at all. It may just be my imagination, or the cold mornings, but it seems to be getting more noticeable. Is this a 'feature' of the engine, or is something wrong? confused

Thankyou!

S600VXR

5,877 posts

223 months

Tuesday 11th December 2007
quotequote all
A knocking at low revs when accelerating is not good!!! Get your mains and most likely big end bearings checked ASAP. Others may be able to say if its a known week point as I read somewhere on here that others have had bearing failure. What ever you do dont drive it! or you will score the crank!

ads_green

838 posts

255 months

Tuesday 11th December 2007
quotequote all
Hows the oil condition and level?

C8PPO

20,464 posts

226 months

Tuesday 11th December 2007
quotequote all
Mine definitely sounds "harsher" when it's cold, the engine has a very different tone, but I'd never call it "knocking". Be interested to hear what you find out.

sarthek

42 posts

220 months

Tuesday 11th December 2007
quotequote all
On cold mornings mine has a noticeable rattle. It worried me somewhat when I first got the car but a brief spell on Google seemed to suggest that the noises I was hearing were all normal, especially as they disappear by the time I've made it to the end of the road.

I think the key thing here is whether it's a "deep" knocking sound you're getting or just the usual, run-of-the-mill clatter that these engines seem to make when first started.

Ston

635 posts

292 months

Tuesday 11th December 2007
quotequote all
Could just be piston slap, although I thought a lot of that was supposed to be eliminated in the LS2. But also could be severe as also stated. I would try and get to listen to one on start up so you can compare, or get it to a garage.

monkfish1

12,206 posts

247 months

Tuesday 11th December 2007
quotequote all
Really depends on the noise. LS1's are invariably noisier than LS2. You don't say which? Impossible to say without hearing it

C8PPO

20,464 posts

226 months

Tuesday 11th December 2007
quotequote all
Mine's the LS2, and as I say, it just sounds "harsh" when it's stone cold. I know what a knocking end would sound like and it's definitely not that - if I had to guess I'd say it was more top-end noise. After 2 or 3 miles when it's properly warmed up, the noise disappears completely anyway.

powermat

35 posts

246 months

Tuesday 11th December 2007
quotequote all
Piston slap! Bearing noise generally gets worse once the oil warms up and gets thinner. As with the LS1 the you occasionally get an LS2 with quite noticeable piston slap that generally disappears after a few miles.
Although I'm sure it will never be a problem if it worries you I'd get it to the dealer to get it fixed while under warranty.

S600VXR

5,877 posts

223 months

Tuesday 11th December 2007
quotequote all
What oil are you using and has it got noticeable since the colder weather set in... maybe need a thinner oil for the cold spell has come about.

BigNige

2,584 posts

247 months

Tuesday 11th December 2007
quotequote all
Could be the rockers with air in them?

ads_green

838 posts

255 months

Wednesday 12th December 2007
quotequote all
Given that the noise is completely gone when the engine is warmeded up I really would say the first point of call would be a full oil change just to eliminate the obvious from the equation.

C8PPO

20,464 posts

226 months

Wednesday 12th December 2007
quotequote all
As far as I can recall it's done it since I had it, which includes before and after a full Main Dealer service with oil change.....

_AJ_

Original Poster:

405 posts

227 months

Wednesday 12th December 2007
quotequote all
Thanks for all the replies people. To fill in the blanks, it's a VXR 500, so LS2, and has done it since I've had it. Only when the engine is cold is this noise noticeable. It gradually gets quieter as engine temp rises, so that by the time it's at normal running temps, it's not audible at all. Oil is in good condition, and has been changed at least twice since I've had it, from 1000 miles, to the 9000 it's on now. It's one of those things that you notice at the time, and then forget about because everything seems to return to normal after a short while.

It's definately your 'deeper' sounding knock, and not top end noisy.

Oil as supplied by Lookers in Warrington appears to be Shell Helix Ultra AG, which is 5W-30 it seems.

marcevo1

524 posts

259 months

Wednesday 12th December 2007
quotequote all
doesnt sound good :-( my gts has done 100k miles with no knocks - so sounds suspect to me.

Black VXR

750 posts

286 months

Thursday 13th December 2007
quotequote all
Does the ls2 engine have hydraulic tappets? I have assumed the tapping I get when cold is down to these building up to full pressure? I had this noise when I used to run an old Rover V8 and assumed that noise when the engine is cold is coming from the same source. Once warm it is fine

ringram

14,701 posts

271 months

Thursday 13th December 2007
quotequote all
Yes all lsx engines have hydraulic roller lifters

Edited by ringram on Thursday 13th December 00:49