Noisy Engine

[snorydermb]

I have a 04 sierra 2500HD with the 6.0 I know this topic has been beat to death but I dont remember anyone talking about the problem I have,everytime I start the truck it sounds like marbles in the engine it doesnt matter if it is sitting for 5 minutes or five hours but it does not do it first thing in the morning no knock or anything,it also does it under light engine load around 1500-2000 rpm like creeping across a parking lot I just wanted to see if anyone else had this problem thanks for any input.

[AD91158]

Make sure your filling your truck up with 93 octane. I experienced a simmilar noise after my dad borrowed my trucka nd tanked her up with regular. The 6.0L motor is intended to be run on high octane premium fuel. Check the owners manual, it specifically says use premium fuel.

[sirjeffro]

My '03 1500HD with the 6.0 manual says 87 octane is fine. My truck has been running fine on BP 87 for over two years. It makes no rattling noise like snorydermb has described. I would suspest something more along the lines of the electronics that control ignition timing. Or.....maybe someone slipped a handfull of marble in the oil pan at the factory.

[ws6_guy]

Supposed to run premium octane on the 6.0Ls??? hmm.... i'll have to look at my book and see that.

 

& sure theres nothing going on with your intake or anything?

[Ranger]

My manual states 91 octane recommended but I generally run 89, occasionally 93...If the gas prices go higher than 3.30/gallon I'm gonna downgrade to 87 and see if the truck can handle it. It knocks a little bit on 89 but not bad.

[04silverado1500]

my owners manual say that all trucks are designed to run off of 87 octane with the exception of the SS which is designed for premium and obviously the d-max diesel.

[Ranger]

I know they're all designed to run on 87, the computer would just retard the timing or whatever in order to keep the engine from overdetonating.

[Nice rig]

I've been running 87 in my 6.0 since the day I got it. I'll occasionally throw a tank of 93 with a bottle of cleaner in it. No problems with the motor what so ever...just as strong as the day I got it.

[cbxeric]

I've been running 87 octane with no problems. Only the vortec max requires premium fuel. You could put some premium fuel in the tank and see if the marbles go away. If they do then there is a problem elsewhere.

 

Good luck..... Eric.

[AD91158]

I would suggest the same, try a tank of premium. If the problem persists you can eliminate that.