Big Block CSK...

Daubs · February 14, 2006

My 04 Crew Cab 8.1 is doing the cold start piston slap / cold start knock / whatever you want to call it.

I called GM and they said the 8.1 isn't one of the engines that traditionally has that problem. They asked that I get my truck checked at dealership (meaning I need to leave overnight...grrrr)

Anyone else getting the knock with their Big Block? And what has GM done about it?

My brother has the knock with his 01 / 5.3 Hoe. GM extended warranty on his engine to 100k.

linda · February 14, 2006

no problems here.

Trouttrooper · February 15, 2006

no problems here.

<{POST_SNAPBACK}>

Mine purrs like a kitten.....wait a minute, this is a big block.....Mine roars like a lion

REBOP · February 15, 2006

check this out :

http://www.#####.com/forums/index.php...pistonslap.com/[/url

sorry, i dont think this works. look up pistonslap.com

opusspyguy · February 15, 2006

My 2002 8.1 sounds like marbles rolling in a cloth bag for about 2-3 minutes on cold start, been doing it since around the 55k mark (95k now). It's annoying, but it doesn't seem to cause any issues.

linda · February 15, 2006

Well, i am sure there will be those who disagree with me and thats fine, but I have talked about this with mechanics (non-GM) and they told me 2 things. One, it is DEFINATELY a problem that GM had with their LS1 based engnes and its an emmbarassing issue that they sometimes will not acknowlege even though its absolutely obvious. Two, they (at least the couple that i talked to) have never heard of engine failure due to piston slap. They say its aggrivating, and tends to make the engine use a little more oil than usual, but has never been the leading factor in engine failure. Bare in mind this is what they told me......i dont know this as fact.

Granted, this was not the topic of discussion, and we did not really discuss it any further, but i trust the two guys that told me this. If i had just paid 30k-50k for a new GM truck/SUV and the thing slapped, i would be pissed without a doubt. It has been shown though, that people with the knock, have seen their engines go easily past the 100k mile mark with no problems. So whatever its worth, if your sitting on an engine that has the slap issue, and it runs fine, your probably gonna be okay as long as you can live with the sound.

opusspyguy · February 15, 2006

Don't get me wrong, I am not happy about it! Just resigned to it since I need to keep this truck another year, and the warranty has been up for quite a while now. I really don't (didn't) have the bandwidth to pursue the issue when it manifested itself and will be selling the truck by the end of the year.

Daubs · February 17, 2006

Thanks Linda. I really like my truck and have heard the "shouldn't have effect on reliability." But I would really like GM to fix the issue or at least extend my warranty, which they did for my brother's 5.3 Hoe.

DiegoYJ · February 19, 2006

My 8.1 has been doing that since I bought it, it also burns at least one quart of oil between changes. I was told it's not a big deal, so I just deal with it. It goes away after a couple of minutes

gmpartsguy · February 20, 2006

Document ID# 650406

2004 Chevrolet Chevy K Silverado - 4WD

--------------------------------------------------------------------------------

Engine Noise on Start-Up, but Only Lasting a Few Seconds

Cause

Correction

Incorrect oil level

Too high an oil level will cause aeration within the oil

Add or remove oil as required to achieve proper level.

Incorrect oil filter without anti-drainback feature

Install the correct oil filter.

Incorrect oil viscosity

• Drain the oil.

• Install the correct viscosity oil.

High valve lifter leak down rate

Replace the valve lifters as required.

Worn crankshaft thrust bearing

• Check the crankshaft endplay.

• Inspect the thrust bearing and crankshaft.

• Repair or replace as required.

Damaged or faulty oil filter by-pass valve

• Inspect the oil filter by-pass valve for proper operation.

• Repair or replace as required.

--------------------------------------------------------------------------------

Document ID# 650406

2004 Chevrolet Chevy K Silverado - 4WD

Found this on GM tech site. Hope it helps.

Make sure you are using a high quality oil filter, that is usually the problem with a cold start knock problem.

linda · February 20, 2006

I use Mobil 1 full synthetic oil and an M-111 Mobil oil filter.

TieRod · February 22, 2006

Piston slap is very common but it will not hurt anything. My 8.1 did it from the day I bought it. If you think the stock piston are bad try a set of aftermarket forged pistons. I had a set of Mahles. When I started in the mornings you asked me. When did you install a D-Max?

mitchntx · February 23, 2006

My '01 does it slaps ... very audible at about 1800 rpms

Daubs · March 13, 2006

Update: Had the Crew in for some service and they looked into the knock issue. Service guy said GM recommended cleaning carbon deposits off the pistons. So they pulled plugs and squited cleaner in to engine, let sit overnight. Got cleaner out and installed new plugs (said old plugs were oil fouled...hmmm).

Truck still knocks, but now it is more like 15-20 seconds after cold start in morning. And it seems to knock more every time I start during the day, not just in the morning. I'll keep my eye (er, ear) on this more and report back.

Will probably have to take in to dealer again soon. Bummer. They gave me trailblazer to drive last time...not as much sack as the Big Block.

D.

Daubs · March 29, 2006

Just got the Big Block back from dealer, again dealing with the knock/rattle issue.

Maybe it's me, but I notice the rattle/knock just about every time I start the truck (as long as it's sat for 1 hour or more). And I started noticing a little rattle at or around the 1,800 RPM mark. They treated me right. First, a little history...

Background: This is a small dealership in rural town of about 4k people. I met the GM/part owner of this dealership when he was with other dealership. He leased me my first new truck back in 99. I've since leased an 01, and purchased 03 Burban and my current 04 Crew. Great guy who really takes care of his customers.

I walk into the service department today and the Service Manager says they are going to put call in to GM and get my engine warranty extended to 100k. And he adds with this, "even if GM won't grant you the extension, if you have trouble you bring that truck back to us and we will make it right, regardless of miles or warranty!"

Nice. Needless to say they are going to have my business for years to come. Doesn't hurt that they beat everyone elses price. And with service like this, how can I go any where else?