Cold Start

[therommelmann]

When I turn on my 2002 tahoe in cold weather the engine makes a strange sound for about 30-60 seconds and then once it warms up it is fine. I brought my car to a chevy dealership and they ran a diagnostics test and they said everything was fine, but this only happens when the car has not been running for 2-3 hrs and I turn it on.

 

[Alex33]

When you get your oil changed, do you use a GM filter or some other brand? I have a similar problem, the engine knocks a little on cold mornings, then goes away as it warms up. A few techs I've spoken with, all owners of Hi-Po GM vehicles, have shared that GM filters have a catch to keep all the oil from draining out of the block and into the filter, but most aftermarket filters do not. For this reason, you will hear a slight knocking as the oil recirculates back through the engine if you aren't using that GM part. I know the place that changes my oil doesn't use them because they are almost $10 and you can find a Fram or other brand much cheaper. If that is the sound you are hearing, hope this helps. If not, I am curious to hear what it is.

 

[therommelmann]

Just found out what the problem is

This link will answer all your questions pertaining to this issue
http://www.pistonslap.com/

 

[Nappers]

piston slap. I use Mobil 1 with Napa Gold/Wix filters, no more slap. 124,000+ miles on the clock.

I also seafoam the Yukon 3-4 times a year (every season)

Aaron

 

[Alex33]

Interesting read, a little broad and reads much more like an attorney trying to get a class action lawsuit going, still a little info is there. Holy Crap!! Mine surely doesn't sound like that. If it did I would definitely be more concerned. My truck just has a light knocking. That sounded like it wanted to rattle itself apart.

 

[therommelmann]

More info

They said over 800,000 GM vehicles were affected by this clanking sound and it is also possible that the sound is turned up a lot on the sound file...all the info on that site seem to explain my problem, except that sound file sounds like it is to loud and two chevy dealerships said that this sound is "NORMAL"...which is exactly what this website says...Also I really really like my Chevy Tahoe a bunch, and I would be miserable without GM...I just want to get this problem fixed in some way or fashion.