Please Provide Suggestions!

fourwheelinfool · October 22, 2007

2002 Chevy 2500HD 6.0L 4L80E 4.10 4X4

First let me say thank you to all the great info that this forum provides. Lots of knowledgeable people here! Let me also thank Haulin' 8.1 for providing some useful advice with spark plugs.

Now here's my problem. I have what I believe is the dreaded "piston slap". A "tick tick tick" that is MOST pronounced during cold starts. The noise quickly dissipated and could not be heard during normal operating temps. Not so much anymore. Now the "slap" stays with me, quieter, but there. I am assuming that this is piston slap, like I said, but I would like to diagnose it as that so that I can sleep better at night.

For about a year I was hit or miss with oil changes as gas ate all my funds. I was poor and broke. I think 10k was not unrealistic for oil changes and I drove my truck every day. Now I treat her better (found some money layin around).

I would like to diagnose and treat this problem. Let’s say I have piston slap. How do I go about treating it? I know that there are cleaners out there that will help for a few thousand miles. The reason I think that (past) oil changes may be a problem is that I know carbon build up is the secondary culprit to The Slap. The first being GM's ill fitting pistons. I would like to do this when I change my plugs.

Now don't get me wrong, I do not doubt the durability of the 6.0L. I KNOW that my engine is one of the best engineered gassers short of the 350. That being said, I would like to be SURE that this is The Slap that I'm dealing with and not a lifter, etc.

I'm looking for treatment options and techniques here. You are guaranteed a how-to after I finish.

THANKS.

ryank1 · October 23, 2007

The problem is not ill fitting pistons, but a lack of a skirt on the pistons. The skirt was eliminated to save on rotating mass and to increase power and fuel economy. As far as treating the noise, You can soak the pistons with either sea foam or GM top engine cleaner. Let it soak in the cylinders for 1-2 hrs and then remove.

KB06YUKONXL · October 23, 2007

I have the same issue with my 2006 Yukon 6.0L at 25,000 miles. Oil changes every 5000 with Pennzoil Platinum 5w30 and still the tick for 2-3 minutes on cold starts until the engine hits 180 degrees. Then quiet as a mouse. I've done 2 techron treatments to no avail. It goes to the dealer tomorrow as they want to rule out valvetrain or fuel injector tick.

jlcallaway · October 23, 2007

I believe I would change to Mobil 1 and drive it without worry. We both have 2500 HD and his slap went away after going to Mobil 1. I have 118,000 miles and he has just over 300,000 and both are doing great.

JoJoJim

fourwheelinfool · October 24, 2007

Let me re-cap:

Treat with engine cleaner and switch to synthetic.

My course of action will be:

1) Inrease oil change to 500 miles, thrice.

2) Treat with top engine cleaner.

3) New spark plugs, Champion single plats.

4) Change oil.

5) I refuse to run synthetic.

Any thoughts?

KB06YUKONXL · October 24, 2007

I would try the Mobil1 5w30. Just to see what happens. I am going to try it.

KB06YUKONXL · October 27, 2007

Ok the dealer says the noise is "normal" for cold start. Went to Mobil1 5w30 and still ticking. I'm going to try 10w30 next OCI.

Ranger · October 28, 2007

Note that once you change to synthetic, you cannot go back to a conventional oil. It will start sludging up your engine.

KB06YUKONXL · November 6, 2007

Note that once you change to synthetic, you cannot go back to a conventional oil. It will start sludging up your engine.

Not for me. I have switched back and forth between syn & dino on several vehicles and never has any issues.

Silverado4x4 · November 8, 2007

Note that once you change to synthetic, you cannot go back to a conventional oil. It will start sludging up your engine.

Thats an old tail and started when synthetic hit the automobile market. Not true. When I had my 2001 6.0 it had the piston slap I started running fuel injector cleaner carbon reducer (comes in a bottle) and the slap was gone, I put a bottle in on a full tank and then another bottle in on the 2nd full tank then every oil change thereafter.

Norseman · November 9, 2007

Note that once you change to synthetic, you cannot go back to a conventional oil. It will start sludging up your engine.

If that were true, how would one explain synblend oils? If it were such a bad thing it seems to me that the engine would just explode if you used a synblend oil

C & A s Dad · November 9, 2007

I will add one suggestion. If your tick, tick, tick is not carbon or piston slap related and is truly some type of lifter noise, the next time you change your oil leave out one qt and replace it with a qt of Rislone. It is not a snake oil or overhaul in a can but it will correct most all hyd lifter issues in an engine. If it does cure your problem, you may or may not have to run it with every change. I had a 3.3L Caravan that developed a lifter tick when it was first started. I could use a bottle of Rislone about every 3 or 4 changes and it kept the noise away.

You want 100QR Rislone and it comes in a bright yellow qt plastic bottle.

KB06YUKONXL · November 13, 2007

Well, On the recommendation of a friend I mixed 3 quarts of Mobil1 5w30 with 3 quarts of Mobil1 10w30 which effectively gives me Mobil1 7.5w30 and ZAMMA........no more ticking at all. My friend happens to be a piston designer at one of the major OEM's and said this will give you just enough oil film to hang on to the upper engine parts to quiet the noise. It has worked down to 39F so far.

Go figure.......he also said if the 7.5w30 mix didn't work the 10w30 should for certain.