Need info on 2500 Suburban w/8.1 eng.

[Mike Lewis]

Wayne---My son is a shop foreman at a local Chev dealer---I asked about oil consumption with the 8.1---he said for a while they were having some problems but it seems to have been from intake manifold gasket allowing oil to be drawn in from underneath. new design gaskets and specific torque on bolts seems to have taken care of that---pieman

[Phil Gobie]

I know they had the Alison trans. on the last year or two they offered the 8.0 does the one you are looking at have the Alison? That would be great if it does.

[wayne.yl]

Originally Posted by Mike Lewis

Wayne---My son is a shop foreman at a local Chev dealer---I asked about oil consumption with the 8.1---he said for a while they were having some problems but it seems to have been from intake manifold gasket allowing oil to be drawn in from underneath. new design gaskets and specific torque on bolts seems to have taken care of that---pieman

Mike,
I will check these out. thanks for the help.
Wayne

[Brad Hunt]

Davis: I have never had a vehicle with this engine but I believe it is safely considered very reliable out to 200,000 miles and probably more if you stay on the oil changes. Big blocks burn a little oil. As an aside Chevy used this engine in their Kodiaks. This is supposed to be a good one.

[Ken J]

I'm really pleased with my so far at 82,000 miles - I figure those pistons are the size of gallon milk jugs, so a little oil consumption is no biggy to me.

Ken J.

[jacarape]

OT question on the motor-Mine uses oil (2002 model with 95k miles on the clock), in line with others on the thread. But it also uses water. I can't see a coolant leak, but your can smell anti-freeze. It seems to be losing about a quart every 800 miles, any ideas?

[subfan1]

You may have a intake manifold gasket failure. My 98 7.4l engine did the same thing. It leaked on the drivers side. I had it repaired about 4 years ago, they used a felpro gasket.
Take a look at your engine between the intake manifold and the valve covers.

[rangebowdrie]

Chevy used a special ring set on those engines, the oil control ring is a 4mm., low tension ring to decrease friction losses. The using of a little oil is normal.

[davidz71]

TSB 01-035- (Oct. 17, 2002) applies to 2002 Avalanche, '01-'02 Silverado, Express, Suburban, '01-'02 GMC Sierra, Savana, Yukon XL and '01-'02 Chevy/GMC C6-7 Conventional Cab Medium Duty and B7 School Bus Models with the 8.1 litre engine (VIN G, E--RPO L18)

"Some customers may comment about higher than expected oil consumption. Because this type of engine is used under various load conditions, the dealer should verify that the vehicle is using more than 0.946L (1 qt.) of oil for every 379L (100 gallons) of fuel used." As stated earlier in a post, oil vapor was being pulled into the combustion chamber through the intake manifold. The correction is to replace all the intake manifold bolts one at a time in sequence to keep the manifold from shifting. Each manifold bolt should be tightened to 44 lb. inches then again in the sequence specified to 71 lb. inches then to 106 lb. inches. The intake manifold bolt part number is 12561518 and you will need 10 of them.