I have an 89 Trooper with the 2.8L v6. I am planning on installing a remaned 2.8 and had some questions:

1. Can (should) the engine and trans (5 spd) be removed as a unit? It would seem to make it somewhat easier to mate the trans if they can.

2. Does anyone have any advice on what to watch out for when installing the intake manifold, valve covers, and exhaust headers? Any general advice of making good seals on these units?

3. Is it possible to pull the engine without disconnecting the AC compressor (can it lay out of the way)?

Any other advice would be welcome. Before everyone gets after me about the 3.4...I know it would be a better choice, but as the Troop is my only transport and this will be my first engine replacement I want to keep the engineering to a minimum.

Thanks in advance...

Should be easier to remove separately vs with tranny & tcase. If your re manufactured 2.8 is from a S10 or camaro the starter is on the wrong side. Or you will need to drill and tap the starter holes, same as a 3.4 v6. You need a v6 from a Trooper or Rodeo.

I'd replace the distributor seal while your at it. There are no headers made for Troopers, but some have modified S10 headers. And yes your can pull the motor without breaking open the AC syst.

I strongly endorse the 3.4 swap. Drill and tapping for the starter is easy.


Finding a 4.3 tbi is easy. Opening up the intake manifold up for a 4.3 tbi is easy. Depending on the 4.3 tbi you find, drilling new hole for the throttle linkage is easy.

A remanufactured 3.1 wouldn't be much more $$$ than a reman 2.8, I'd recommend that option. The increase in torque over a 2.8 would be worth it.

You'd want a 3.1 out of a 4WD Rodeo or 4WD P'up. Or, the mid-90 series GM FWD minivans had the same block (cast-iron heads, TBI intake manifold, same motor mount points, and starter on the correct side already to fit a Trooper).

Since you're spending all that $$ on a reman'd motor, why not give yourself an easy upgrade while you're at it? 2.8 and 3.1 are the same block, the only diff is the stroked crankshaft and pistons to match.

I'd recommend (whether you use 2.8 or 3.1) that you use a clutch from a Rodeo/P'up 3.1 (4WD MUA-5 Tranny only). This is a 24-splined clutch disc with a larger diameter than the 2.8's clutch disc and is a much better setup with a lot more holding power. A direct swap for the 2.8 clutch with no mods whatsoever.

Don't forget to install a new pilot pushing in the crankshaft.

The intake manifold should be sealed with the latest-recommended GM sealant (yes, they really do specify a certain sealer for this). Pick up a cartridge of it (for use with a caulking gun) at your GM dlr. Be sure the intake is properly torques as loose/leaking intake is a problem area for this motor.

GM uses metal-to-metal seal on the exhaust manifolds, Felpro and others have a nice gasket which will be much better, not leak, and probably help with the busted man bolts issue. Be sure to replace any questionable bolts and use anti-seize on the threads. I upgraded my exhaust man bolts (except for the special ones) with higher-strength items. None have busted yet!

A quality valve gasket like Fel-Pro should seal just fine, use a sparing coating of Permatex Ultra Copper, Hi-Temp Orange or equivalent "O2 Sensor Safe" RTV.

By all means replace the dist. O-ring, it's a known problem area too.

Far as removing the engine goes, you have a couple of choices there for wiring; either disconnect all the wiring harness on the motor and peel it off, leaving it in the engine compt; or, disconnect the O2 sensor wire, pull it back from the driver's side by the cat, all the way to the pssgr's side back of the motor, then disconnect the motor harness and pull it out along with the motor. The O2 sensor wire is the only thing keeping the engine harness from freeing up. And Never cut this wire thinking you can just splice it later! It's a special shielded wire and splices just don't work right.

-There isn't enough clearance to split engine/tranny and have the trans pilot shaft make it out of the clutch fingers without destroying the clutch. You'll need to drop the axle to gain more room.

-Axle is held on with 2-per-side monstrous bolts up into the frame, if you have a good air compressor and an impact wrench it'll help immensely.

-Unbolt the front driveshaft at the transfer case and swing it out of the way. It'll give you a lot more room to work around engine stuff, underneath.

Invest in a set of metric Gear Wrenches, you can't believe how much they help when working in the tight spots around this motor. I found the straight ones without a toggle to reverse ratcheting action will fit into tighter spots than the 'bent-headed' wrenches.

-To get at the very top bell-housing bolts, 2 things help; a very long set of 1/2"-drive extensions and breaker bar/ratchet/impact, and/or removing the motor mounts off the block, once you've got a pick on the motor with a hoist.

-You'd use the long extensions to reach from over the tranny, fwd to the bellhousing bolts. They really are that bad of a fit to the firewall.

-Pulling the motor mounts off the block allows you to lower the engine down just a wee bit more, and that may make it possible for you to fit a Gear Wrench in there and get at least some of the bolts loose from inside the engine compt.

-Needless to say, pulling the hood is just about mandatory. Be sure you mark the hinges so you can get everything bolted back up to its original position. And save all the hardware, very frustrating to be ready to bolt the hood back on and can't remember where the bolts went!!!!! <img src="/forums/images/graemlins/angry.gif" alt="" />

-On your A/C unit, some are shimmed so when you unbolt it, be sure to note the position of any shims and put them back the same way. This was a factory TSB regarding serpentine belt vibration so you really need them if they are there. If you have enough room to get the hoses out of the way, you may be able to keep from losing your Freon. I never had that problem 'cause none of the rigs I worked on had a working A/C system!

That's all for now, I'm sure something else will come to mind. Keep up the questions and we'll get you there!

HTH...........ed

BTW your motor can be converted into a "3.1 Stroker" with simple addition of any 3.1/3.4/3100/3400 crankshaft and the correct set of pistons (meant for an Iron-Headed 3.1 only). I did that very mod to an '89 2.8 Trooper I built for my Folks.....ed

Ed..I much appreciate all the advice..one follow-up question regarding the 3.1. What year and vehicles did the 3.1 come in that had the starter on the correct side? Given that the 3.1 is more expensive and I may have to suffer a hit on the core charge is the upgrade worth it?

Also, can I drop the tranny (5spd) completely out without removing the axle bolts?

Based on your experience, what would you recommend with regard to your advice on the wiring harness?

Thanks.

Early '90's Rodeos and P'ups up to about '94, far as I can recall. Until Isuzu switched over to the all-aluminum 3.2. As long as the motor comes from a 4WD Rodeo it's the right 3.1. And in P'ups only the 4WD came with a 3.1 V6 so you're safe with any P'up 3.1.

As for the GM FWD minivans, I found some interesting info at this website:

http://www.psengines.com/GM6.htm

If you scroll down the page a bit there are 2 places which describe the correct motor, 1st is for '90-'93 3.1's with VIN "D" or "Z", as follows:

"GM Chevrolet, FWD, T.B.I., APV Van, Cast Iron Heads, W/O Trigger Fire Ignition, Has Center Reluctor Ring W/ or W/O Notches, May have Fuel Pump Hole-But is not used, Not Trigger Fire, V6 Trooper, Rodeo, Driver side starter. (Not For T.P.I.)"

Then there's the same info for '94-'95 3.1's with VIN "D":

"GM Chevrolet, FWD, T.B.I., APV Van, Cast Iron Heads, W/O Trigger Fire Ignition, Has Center Reluctor Ring W/ or W/O Notches, May have Fuel Pump Hole-But is not used, Not Trigger Fire, V6 Trooper, Rodeo, Driver side starter. (Not For T.P.I.)"

Note that the engine rebuilder includes both Rodeos and Troopers as potential recipients of this motor, confirming that it can be used in the Trooper application. BTW they made so many of these minivans that I wouldn't be surprised if you found a good useable one at a wrecking yard. Try doing a query at www.car-part.com for yards in your area and you may be surprised.

The critical thing to look for if you're stomping around in wrecking yards would be cast-iron heads and TBI intake, just like your 2.8.

I'd expect that a rebuilder won't much care about the core difference between a 2.8 and 3.1. If anything, useable 2.8 crankshafts are probably worth more than 3.1/3.4 etc, just 'cause there's so many more of the FWD alum-headed motors running around. 2.8's aren't so common anymore.

Don't forget that block and heads are identical between 3.1 and 2.8, so you're only talking about crankshaft and pistons which they reman/replace anyway. I'm sure that most rebuilders would have a big pile of 3.1/3.4 core crankshafts just laying around.

I'd imagine you can pull the tranny first, but it seems like so much extra work. If you absolutely can't get the axle dropped I reckon it may be your only option. Unless you want to loosen body mounts and jack the body up!!! Then you'll have lotsa room!

On the wiring harness, I think it's a bit of a pain to unravel the O2 sensor wire, 'cause it snakes all over the tranny from one side of the rig to the other. But it sure does make it a lot "cleaner" to pull the engine harness out with the engine. I really didn't like trying to route the harness all around the engine on the 1st V6 Troop I did, since I didn't undo the sensor wire on that one.

So, guess I'd say I Dislike Less unraveling the sensor wire, than I Dislike unwinding the engine harness! Lesser of 2 Weevils so to speak.

Last thought, if you don't have time constraints, just have your old motor rebuilt. 3.1 crank kits aren't that expensive and they'd be putting new pistons in it anyway. There are tons of good used 3.1 crankshafts and crank kits on eBay, for example. It's where I picked up one for my 3.1 'stroker' motor (pistons too).

Note that any 3.1/3.4 crankshaft, with or without the trigger ring (reluctor) works, the reluctor ring is for MPFI motors with crankshaft sensor and we don't need that since we use Stone-Age distributors!

And if you should happen to come across a Smokin' Hot Deal for a 3.1 Camaro crank, rods, & pistons, the internals are a Drop-In to your block. I don't know if there's enough meat on a Camaro 3.1 block to drill for driver's side starter, but I wouldn't bet on it. Far easier to use your block.

HTH..............ed