So like my intro says I bought a 1991 Isuzu trooper. Its got an automatic trans and the 2.8L GM motor. The trans is shot...not shot shot but needs work. So the other day I dropped it and sent it off to the shop. Now that the trans is out I'm wondering if I should just pull the motor and freshen it up? I honestly think its easier to pull the motor and trans next. So my questions are:

Is it easier to put the motor and trans in together? Possible?

and

What are the recommended touch ups I do to the engine? I was thinking about replacing the rear main seal, water pump, complete tune up, new gaskets for the valve covers, adjust the valves etc

The motor fires up every time and runs well but if I have the chance why not take advantage of it.

Thanks!

Ryan

 

The GM 2.8s are notorious for having a problem where some of the coolant passages were engineered to be too close to some oil passages and that whole thing would get close to one of the outside cylinders where the top of the cylinder meets the cylinder head.

So the general pattern has been that contaminated coolant eventually eats through some point where the intake manifold and heads meet, then the issue works its way into an oil passage, mixing coolant and oil. The vehicle can actually be driven like that for quite some time, but will be losing power then eventually blow the motor in such a way that it is not rebuildable according to people who told me how it goes on a lot of the Chevy S10 series.

So in maintenance, the trick is to keep the motor relatively clean and look for those first signs of some head gasket leaks or leaks around the manifold gaskets. Apparently if they are caught early in the game, things can be done to head off disaster, especially with some newer technology like using a TIG welder to beef up the problem area with new metal. Another trick I have been told about is to periodically flush the coolant and add alumna seal to it on a somewhat regular basis. The Alumna seal will then circulate to the areas where the passages wore thin and work its way into the cracks that might be forming.

I have heard of engine rebuilders beefing up some of the motor components in those critical areas where they are known to fail and then it is a done deal, the motor will last as long as any other quality V6. Apparently some GM subcontractors were also beefing up a few of those components or just being more careful on quality control at some point later in the production of the 2.8 series motors, and yours being a 1991 would put it fairly late in the series. It could be that you got one of the good motors even though the 2.8 has generally been considered one of GMs big mistakes.