Hey guys....I have 40,000 miles on my 07 h3 soo far, and when i bought it it had 33,000. I noticed when i bought it that on cold startup, the engine had a rattle/knocking noise for the first couple seconds......now it seems to do it not on cold start, but anytime it is off for more than a few hours....of course the dealer said they didnt hear anything abnormal, and suggested a ac delco oil filter with anti drainback valve.....well, still does it and seems to be getting worse.......anyone have the same experience? Timing chain noise possibly? Or piston slap? what to do.....if its gonna break, hope it does before my warranty is gone....

 

I had possibly the same rattle not so much of a knock though, the rear bolt on my exhaust manifold had broken off causing an exhaust leak. The dealership had been telling me the same...nothing abnormal. I finally spoke to the service manager and told them that it needed to be checked for an exhaust leak before it causes more damage...fixed the next day.

 

thanks....but its coming from inside the engine and goes away after a couple seconds, as if after oil pressure builds.....

 

Broken exhaust manifold bolts maybe.

 

My 07 has that cold start up rattle (knock) which started at 48,000. now have allmost 60,000.I tryed heaver weight oil thinking it was oil draining back thru the filter.Didn't work. Went back to 10/30.It sounds like the lifters are loosing there oil overnight and are pumping up at startup.Tom,

 

yup , thats the noise.....anyone here have this happen and get confirmation from the dealer? surely someone has ........thanx guys.....oh and all exhaust manifold boltsare good......worth a look..

 

I have an o7 with 29k miles. I have been complining of an internal engine noise since I first purchased the vehicle. On my fourth visit I made them start while I was there, they could not deny and admitted the noise, it only lasts a few seconds when the engine is started after sitting for a while.
The dealer called tech assistance and was told to replace the timing tersioner as a good will action but that the noise is normal because there are gears involved in the timing and the camshafts.
First let me tell everone that I am a retired 30 year Master Tech with Chevrolet and this is bull. There is no reason for the noise, if anything is a desing failure not a normal condition.
Anyway after they replaced the timing tensioner the noise was reduced considerably but it came back louder after 4 months and they refuse to do anything about it.

Any suggestions? This is a lot of crap since the partd are going to fail when the vhicle is out of warranty and we will get stuck with the bill.

 

Congratulations on digging up an ancient thread.
30 years as a chevy master tech and you can't diagnose a noise problem yourself?

 

well tal, why dont you tell us all just what is causing the noise if its so easy to tell. surely those 1984 hummer i5 engines had similar problems huh!

 

Every I5 H3 I have ever been around sounded like that. It always goes away after the engine warms a little. I just think it is building oil pressure.