2002 Suburban 2500 w/ Vortec 8100 V8

[rationull]

Looked at the car in the subject this morning at a nearby "Fleet Liquidation" lot. It's an ex fire department vehicle, a little stripped inside (not too bad, third row seat and front center console are missing, nothing we care about). I gotta say, it felt like a big improvement over our '99 model with the 7400 (on the older platform). Better throttle response (could partially be due to the electronic throttle), better steering feel, more solid brakes (rear discs vs drums are probably part of it). Lighter than our truck since it's only 2wd too.

We've been passively on the lookout for a newer truck for a while and this one looks like a possibility. The price is pretty good, and it's only got 92k miles on it (ours has 170k or so).

Are the 8.1 liter big blocks susceptible to the same LIM gasket problems that the 7.4s are? I just finished replacing the gaskets on ours and am not really interested in doing it again.

It's got a "Service Ride Control" message on the dash that I'm not sure what to make of. I assume this is from a self-leveling air suspension but I looked for airbags on the rear axle and didn't see any. Is this something built into the shocks? Or maybe the shocks were replaced and the airbags removed w/out disabling the light.

 

[JHZR2]

Last of the big blocks... Neat truck.

 

[Chris142]

The 8.1 is very simmiliar to the 454. Intakes can leak on those too. FWIW They use a different Radiator and I can't get an aftermarket one. Had to get the last one from GM and my cost was nearly $900.

 

[rationull]

Last of the big blocks indeed. That's one of the reasons I'm kind of enamored of this truck. I like our 7.4 but the vehicle as a whole just doesn't feel quite as solid.

That sounds a little scary about the radiator. I had heard something about oil potentially leaking from the intake gasket, but is the problem actually the same as on the other engines? Ours had an internal coolant leak and I don't want a repeat.

 

[rationull]

Also are there any good resources for information on the autoride system? I've read various things indicating it could be either an air system or a electronic shock valving system (presumably the latter would be just for ride comfort?).

http://www.arnottindustries.com/ is supposedly the company that makes the air suspension parts. They only list parts for the 1500 Suburbans. That seems like a good sign to me -- seems like maybe electronic shock valving wouldn't be as critical to safe operation and towing as an air suspension would be.

 

[LordAbbett]

I had a 2006 chevy w/the 8.1. And I thought it was a dry intake manifold!? No coolant in the manifold due to external crossover. It picked up coolant out of the end of the cylinder head. I know the thermostat was not in the same location on the intake as it was on the 454.

 

[rationull]

Originally Posted By: LordAbbett
I know the thermostat was not in the same location on the intake as it was on the 454.


I noticed that when looking at it today. Upper radiator hose still connects to the t-stat housing, but the t-stat was off on its own separate little "pillar". The whole engine bay actually looks much tidier than my GMT400's.

 

[caravanmike]

being a ex fire dept vehicle, u need to find out if it had 1 driver (chief) or if it was a staff car for getting lunch etc. if it was a staff car it could of had over 60 drivers. mike

 

[ls1mike]

No coolant flows throught this intake manifold.
They can leak oil. You also only get the 4L80E, which is good don't get me wrong. I have one in my truck and it is very good, but the Pickups with the 8.1 have the Allison.
My truck was fleet vehicle. I got a heck of a deal on it and it has been very good.

 

[boosted]

Those 496 cubic inch big blocks love the oil, I have a friend that has a fleet of three with the 8.1/496 and they all use oil pretty good, he must not care as he just bought another one except it's the 2500 avalanche with the 496

 

[LordAbbett]

It seems all the 8.1 engines used some oil. Low tension oil rings maybe? My 2006 in silverado; After an oil change it would use a pretty insignificant amount in the 1st 1500 miles. The next 1500 miles it'd use 1/2 Qt and then it would be changed at one year mark even though low mileage.
I liked that old big block. sweet engine as long as you don't rack alot of miles. It is no mileage master. But hey my current truck is a V10 Dodge

 

[Brigadier]

Use Amsoil. My dad's 2002 2500HD 8.1L used about a qt every 1000 miles or so[since new] until I convinced him to switch to Amsoil. Doesn't hardly use any now. If you do not like Amsoil, use the highest flashpoint oil you like.

Originally Posted By: boosted
Those 496 cubic inch big blocks love the oil, I have a friend that has a fleet of three with the 8.1/496 and they all use oil pretty good, he must not care as he just bought another one except it's the 2500 avalanche with the 496

 

[hattaresguy]

In the marine world 8.1's are pretty good, they replaced the old 454 and 502 and really are better motors. I don't know how they hold up on trucks but on boats they seem to do pretty good.

 

[ls1mike]

They use less oil when they work. It is common for the 454 and 8.1 to use it. When they are loaded up they seem to do better. My old 454 used hardly any oil when towing, when tooling around town it would use it.

 

[hattaresguy]

My grandfather had a pair of old 454's in his Chris Craft, never burned a drop running 3,200rpm all day long and pushing 14k pounds of boat threw the water. Burned about 20gph each though at WOT. If he kept the boat it was getting 8.1's which would probably knock a few gallons off that figure and had a lot more HP.

 

[SteveSRT8]

Originally Posted By: ls1mike
They use less oil when they work. It is common for the 454 and 8.1 to use it. When they are loaded up they seem to do better. My old 454 used hardly any oil when towing, when tooling around town it would use it.


This is my experience also. Had a 454 car and truck, and neither seemed as thirsty for oil when you ran them HARD. My dad had one that was a complete doggy though, perhaps the production tolerances are poor on these?

 

[bbslider001]

Originally Posted By: Brigadier
Use Amsoil. My dad's 2002 2500HD 8.1L used about a qt every 1000 miles or so[since new] until I convinced him to switch to Amsoil. Doesn't hardly use any now. If you do not like Amsoil, use the highest flashpoint oil you like.

Originally Posted By: boosted
Those 496 cubic inch big blocks love the oil, I have a friend that has a fleet of three with the 8.1/496 and they all use oil pretty good, he must not care as he just bought another one except it's the 2500 avalanche with the 496


Amsoil does not make one bit of difference on whether a truck uses oil or not, and even if it did, how does the OP save anything when Amsoil's $10-12 a quart vs. $3-4 for dino/conventional? Really bad advice....and I am saying this being a former Amsoil junkie with some good experience. Any syn is good for long OCI's and that is it. Dyn vs. dno has nothing to do with consumption, protection, or engine performance.