Piston Slap

Jansen · February 8, 2007

For those with piston slap, is anyone seeing it lasting longer and longer. In where I live (cincy Ohio) we've been between zero and 5 each morning for the last two weeks. My truck used to quiet down in about 45 seconds, now it is lasting longer than 5 mintues and normally doesn't stop until it has been driven a few miles.

Anyone seeing anything similar? Once the engine is at operating temp it stops but I am wondering if something is starting to wear more.

Same oil since new, so it isn't driven by an a different brand/grade of oil.

Jansen

jhm · February 8, 2007

For those with piston slap, is anyone seeing it lasting longer and longer. In where I live (cincy Ohio) we've been between zero and 5 each morning for the last two weeks. My truck used to quiet down in about 45 seconds, now it is lasting longer than 5 mintues and normally doesn't stop until it has been driven a few miles.

Anyone seeing anything similar? Once the engine is at operating temp it stops but I am wondering if something is starting to wear more.

Same oil since new, so it isn't driven by an a different brand/grade of oil.

Jansen

I don't normally have any csk or piston slap noise, but we also have had temps around 5-10 and when I start it I hear a slight knock for about 30 seconds. I would say 5 minutes is a long time to knock.

Jansen · February 8, 2007

It has me very concerned.

Jasnen

the hammer · February 9, 2007

For what it's worth, when I fixed the piston noise at start-up in my C5 corvette, all it took was to change the oil filter I was using. I started using the PureOne (not the regular purolator )filters and my startup noise went away. Used Mobil 1 all the time. If you haven't tried using good flowing oil and a filter that allows great flow, it may be the easiest fix to your problem. It was what the doctor ordered on the vette.

Jansen · February 9, 2007

I'm not sure the oil will fix this one. I've been running mobil 1 10W30 fully synthetic and it keeps on ticking. I've been running the mobil filter too. I may try a different filter this time but the engine ticks with 5w30, 10w30 doesn't really seem to effect it. I just alarms me that it the noise takes longer and longer to go away.

Jansen

pm26 · February 9, 2007

I'm not sure the oil will fix this one. I've been running mobil 1 10W30 fully synthetic and it keeps on ticking. I've been running the mobil filter too. I may try a different filter this time but the engine ticks with 5w30, 10w30 doesn't really seem to effect it. I just alarms me that it the noise takes longer and longer to go away.

Jansen

Forget the oil. To get rid of the piston slap at least temporarily, you'll need to use GM Top Engine cleaner. This is how dealers took care of the issue under warranty. I think they removed the plugs and injected the cleaner into the cylinders to soak into carbon and dissolve it.

You'll have to keep redoing this about every 5k miles.

jhm · February 9, 2007

Anyone know if the '07's still have this problem, oops I mean normal noise?

ottguy · February 10, 2007

Well I had CSK with my 4.8

When I switched over to synthetic the knocking stopped and it's been -20 or colder some mornings here.

Maybe each truck is different my brother-in law started using high mileage oil in his engine and it helped quite the knocking also.

CoastyAV8R · February 10, 2007

It seems like these are 2 different problems. Some have a knock from excessive carbon build up in the cylinder while others hear the knock and take care of it by switching to a lighter weight/free'er flowing oil system. In my experience, the knock from excessive carbon build up won't go away when the vehicle warms up and you would have "pinging" under engine load. Mine ticks a little when it's cold but in Hawaii I don't get exposed to the cold climates that others do or it would probably be more pronounced. I use a synthetic motor oil and I'm really considering the GM Top Engine Cleaner to see if that makes a difference, this was first time I heard of it.

Norseman · February 10, 2007

My neighbor had CSK in his 5.3 and he sprayed dang near an entire can of Seafoam Deep Creep through the intake and the knock hasn't come back for almost a year now. I'm not telling you to do it, but it worked for him.

Jansen · February 10, 2007

This is piston slap on mine, that I don't think is caused by carbon. The reason I say that is I noticed it doing shortly after I first bought it. THe dealership that I purchased it from said "yep, cold start knock" but there is no GM fix.

I"m still running the same mobil one grade of oil, just curious as to why it is lasting longer and longer.

Norseman · February 10, 2007

This is piston slap on mine, that I don't think is caused by carbon. The reason I say that is I noticed it doing shortly after I first bought it. THe dealership that I purchased it from said "yep, cold start knock" but there is no GM fix.

I"m still running the same mobil one grade of oil, just curious as to why it is lasting longer and longer.

Have you tried something to get rid of carbon build up? If not why not try it??

Jansen · February 12, 2007

It can't hurt to try. It has been so cold in ohio lately though that I haven't really been able to do much to it.

One puzzling aspect is the blow by oil. The truck has always burned oil (1qt per 4000 or so) since new. Of course GM said this was 100% normal. However, when it is a cold start, you can feel air coming out of the oil fil tube. When warm, you don't feel this. I don't have a way to accurately state if it is burning more now, then say 20,000 miles ago. That is why i don't think a carbon cleaner will do anything.

Jansen