Rattle on cold start-up

HP Dude · 19-05-2006, 02:57 PM

Hi guys,

Have noticed in the last couple of weeks that when I start my XR8 after it has been standing for a few days, that just after the engine fires, there's momentary metallic sounding rattle coming from the engine. It goes away after a second, and doesn't return on additional start-ups when the car is warm. Also, if I start the car the two days in a row (i.e when it just sits overnight), the rattle is much more quiet, or not really noticeable.

Any thoughts? All comments/suggestions appreciated

HP Dude.

sbutler · 19-05-2006, 04:07 PM

There is a thread about this very thing. But I will anwser you anyway.
Give your XR an oil & filter change, use a 10/40 oil [non synthetic]
Helix plus 10/40 is what I use in my TE50 I sure that will fix the rattle at startup. Change your oil every 8 to 10,000Ks..

HP Dude · 19-05-2006, 04:44 PM

Quote:

Originally Posted by sbutler

There is a thread about this very thing. But I will anwser you anyway.
Give your XR an oil & filter change, use a 10/40 oil [non synthetic]
Helix plus 10/40 is what I use in my TE50 I sure that will fix the rattle at startup. Change your oil every 8 to 10,000Ks..

Thanks, I'll give it a try.

I did a search but couldn't find that thread. Sorry for the repost.

howesy · 19-05-2006, 05:44 PM

Quote:

Originally Posted by HP Dude

Hi guys,

Have noticed in the last couple of weeks that when I start my XR8 after it has been standing for a few days, that just after the engine fires, there's momentary metallic sounding rattle coming from the engine. It goes away after a second, and doesn't return on additional start-ups when the car is warm. Also, if I start the car the two days in a row (i.e when it just sits overnight), the rattle is much more quiet, or not really noticeable.

Any thoughts? All comments/suggestions appreciated

HP Dude.

Sounds silly I know but start it cold and while you hear the rattle spray or throw some water on the idler pulleys and belt, noise will go if culprit. If its a rattle more than a knock then this can sometimes be the culprit and new idlers are cheap as chips. Found that to be the problem also on sons EF XR8.

HP Dude · 19-05-2006, 06:13 PM

Quote:

Originally Posted by howesy

Sounds silly I know but start it cold and while you hear the rattle spray or throw some water on the idler pulleys and belt, noise will go if culprit. If its a rattle more than a knock then this can sometimes be the culprit and new idlers are cheap as chips. Found that to be the problem also on sons EF XR8.

Thanks! The XR8's due for a service so if the oil and filter change doesn't work, I'll look at the idler.

JC · 19-05-2006, 10:26 PM

Muzza had a rattle at startup - only when cold. Replaced his battery and no more noise/rattle. Turns out the old battery was probably not supplying enough power to the starter to retract the little cog from the flywheel, which was causing the rattle. At least that's our theory, anyway.

EBFalcs · 19-05-2006, 10:34 PM

what are all these strange answers, everyone knows that in cold weather the oil goes thick when cold and has drained to the sump and takes a while to get pumped up to the rockers. that's all there is to it

HP Dude · 20-05-2006, 01:08 AM

Thanks guys, appreciate all input. The battery is an interesting suggestion, as it was recently flat due to the car being under used. Might change the battery in the course of servicing.

EBFalc's suggestion also makes perfect sense as it occurs when the car stands for days on end without being started, although we have other cars that are rarely driven, and I don't recall them making the same rattle on start-up. Anyway, as long as it is not symptomatic of a more serious (read expensive) problem, then I'm happy!

jimt3te50 · 20-05-2006, 01:23 AM

Hypeurtectic pistons can rattle on start up too, until they come up to temperature and expand......

Probably not it, but they do

SirHenry · 20-05-2006, 11:22 AM

I had a very similar noise a metallic type rattle on start up only when cold, turned out to be the exhaust touching the sump.

GK · 21-05-2006, 04:57 PM

Quote:

Originally Posted by jimt3te50

Hypeurtectic pistons can rattle on start up too, until they come up to temperature and expand......

Probably not it, but they do

Sounds like a monaro problem! LOL!

GK

You Yangs · 20-05-2006, 06:15 PM

My AU Fairmont V8 has had this sound for 4 years and 100000 kms
Tried all types of filters and oils with no difference whatsoever
I don't think its a flat battery ive replaced 2 in that time but the pulley and belt thing that howesy talks about could be it