2001 2500HD 8.1L Spark Plug Problem

SoCADesertRat · July 29, 2006

At 52,000 miles I changed the plugs. Cylinders 3,4,5,7 had very fouled plugs (oil), while 1,2,6 had smaller amounts of fouling and number 8 had none. I just pulled the replacement plugs (ACDelco 41-983) 13,000 miles later and they are showing similar symptoms.

At the 52,000 mile plug change I also changed the 10 Intake Manifold Bolts as specified in GM Document ID# 1159636 [High Oil Consumption (Replace Intake Manifold Bolts) #02-06-01-035 - (Oct 17, 2002)].

Since that didn't make a difference in the plug fouling, I now have GM Document ID# 1684617 [Excessive Oil Consumption - keywords bolt gasket head intake #PIP3193B - (Jul 14, 2005)] which gives instructions on changing out the intake maniforld bolts (again) after changing the intake manifold gasket. The new gasket (Part #890177539) is said by GM to make a "more robust seal" and has been used by the factory in the 8.1 since midyear 2004.

I am adding an average of 1 pint of 10W-30 (conventional oil) every 100 gallons of gas (+/- 1.000 miles). I know this is less than the GM stated 1 qt. per 100 gallons, but that doesn't make my problem any less.

Anyone going through or been through this dilema? Since the GM-Tech is currently off-line, I would appreciated very much in hearing from you.

Thanks in advance,

Gib

Frotax · July 29, 2006

Post a pic of the plugs.

SoCADesertRat · July 30, 2006

Post a pic of the plugs.

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I took 7 photos, all plugs are in each one. These are the 52,000 mile plugs.

Some pics are more clear than others. Thanks for your help and patience.

01 2500HD Fouled Plugs

Thanks,

Gib

dizzy · July 30, 2006

I had a very similar thing happen on my 2000 Silverado Z71 1500 5.3L, it had 65,000 miles on it when I traded it. I know I had hit the speedo/rev limit a few times going down to LA once and the computer shut down the fuel (and yes still got passed).

I was burning a quart of oil each way to LA it was only 327 miles each way.

And I faithfully changed oil & filter in that truck every 3000 miles from day one, I used straight 30wt Valvoline and a WIX filter. When I really started noticing it, I'd look in the rear view mirror and see blue smoke when I let off like taking the off ramp on the the freeway.

I dumped some Marvel Mystery oil in it before one oil change and it seemed to help. I traded mine in on a new one before I had to fix it.

I would try some Lucus Oil Treatment in it, at least you'd know everything is getting lubed properly. You can always do a compression check to rule out if its the rings or valve guide.

Did you ever use any of that Prolong engine oil treatment stuff in it?

I did in my 2000, when it had about 12,000 miles on it, one guy thought that it never got broken in properly. I never did baby it, I drove it the way I was going to drive it. My 2005 takes 5wt-20wt, stuff is thin as water. I'm using Synthetic in it now and changing every 4,000 since that 3,000 interval didn't seem to help any.

Those spark plugs are supposed to last like 100,000 miles if you install the titaniums.

dewfpo · July 30, 2006

Does your 8.1 have the fixed orifice PCV valve?

DEWFPO

ABQFirefighter · July 31, 2006

Enlighten me on this, will you?

Does your 8.1 have the fixed orifice PCV valve?

DEWFPO

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dewfpo · July 31, 2006

My understanding is that the early 8.1's had a standard variable PCV valve which apparently seemed to be casusing oil consumption issues. I heard they switched to a fixed orifice valve and that seemed to help with the oil consumption in combination with the new manifold gasket/bolts.

My 05 burns hardly any oil at all.

DEWFPO