Engine Swap?

Hello All. I have a 98 GT sedan (92.5k miles) And is consuming coolant and engine oil. None of those are coming out in the exhaust, so I am wondering what the hell is going on there. She runs very fine and strong, no strange noises or anything like that. But that worries me and I am a freak that swore back when I was 8 that will never sell a car of mine providing I will be able to maintain them. I love the GT! So, I was wondering if an engine swap would be reccomendable in this case, to a 3800 Series III Supercharged. Will the same tranny work? How much shall I pay for it? I have one in the net for $3,900, new from GM Performance.

All info will be much appreciated!

Thanks!!

well...i wouldnt exactly jump into a moter yet, unless you really want to make your GT into a GTP. I'm just gonna warn you, its not a real easy job :tongue: i did it to my SE.

the tranny will work, but w/ your car having 98K on it, i guess it depends on how much you took car of the tranny, will the tranny last you

the GTP comes w/ a 4t65e-hd version, where as your gt has the non hd version. the hd is just a little more built up. My SE still has the original tranny in it...and is still shifting strong, considering the fact that i have a ZZP shift kit, and Desert Fox transmission cooler.

i was lucky, and found a supercharged 3800 motor w/ 60K on it in the junkyard that my dad deals with for $1000.00 shipped, but he also owns an automotive business and deals w/ them regularly.

shop around and see what you can find, but you should expect to pay anywhere from $2500-$3500 for a decent motor.

Ok, thanks! Then, anothe Q, you think it would be worthy then rebuilding the my stock engine completely?

[quote=grandprixgtx00]well...i wouldnt exactly jump into a moter yet, unless you really want to make your GT into a GTP. I'm just gonna warn you, its not a real easy job :tongue: i did it to my SE.

the tranny will work, but w/ your car having 98K on it, i guess it depends on how ...........



Ok, thanks! Then, another Q, you think it would be worthy then rebuilding the my stock engine completely?

I recommend you do four things first:

1. Is there water in your oil? Does it look like light brown milk?
2. Pull your plugs and observe if any of them are firing in oil.
3. Pressure test your cooling system and determine where you are losing the coolant.
4. Crawl underneath the car with a mini-mag or equivalent flashlight and thoroughly inspect the bottom of the block for oil and coolant leaks/trails.
Do those 4 things first to determine what is going on with the engine.

Come back with your findings on the forum.

The consensus of the advice on this website is not to bother converting your GT into a GTP. RichTaz has a few write ups on this issue.

Plus, you did not say what state you are from. If you are from California like I am, forget it. Your VIN will bust you on smog day if you try to attempt to "smog it on the fly." Here, you have to go through the hassle of the smog referee certifying the vehicle it's smog legal with the blower and its multitudes of factory changes & upgrades have been installed correctly.

FWIW: It sounds like you may have issues with your LIM & UIM gaskets. Pretty easy fix. Less than a $325 DIY job. Let us forum folks know what you find out. :)

well...i guess what i would find out first is where your oil/coolant is going. did you ever overheat your motor? you may just need to replace the head/intake gasket.

if you overheated it multiple times, you may need to replace the heads. but i find it hard to believe that you have a bad 3800 on your hands at 98K, unless the car was beat to he!! all its life

Do a forum search on losing coolant, UIM, LIM and start there. The upper plenums are common to fail, as well as the lower intake gaskets on the 97-03 3800 series-II and are probably the cause of your coolant loss.

To the OP... Did you want to swap a supercharged 3800 into your car? I thought I read that you went to put in a 3800NA series 3. I think somewhere in the posts we got confused. Please clarify. Not sure if swapping a series 2 for a series 3 would work or not.

To the OP... Did you want to swap a supercharged 3800 into your car? I thought I read that you went to put in a 3800NA series 3. I think somewhere in the posts we got confused. Please clarify. Not sure if swapping a series 2 for a series 3 would work or not.

good call TBlake...it does say supercharged 3800 Series III.
as to that...I'm not sure if the series III will work w/ your tranny. i know the series II will though.

Actually I think it will bolt up no problem, but as with any swaps having to do with superchargers, many other things have to go with. (as you probably know... 3100 to 3800 supercharged in an SE) Fuel pump/PCM/Tranny/Wire Harness

If I were him, I'd first look into finding out where the coolant and oil are going.

If he still wants to do the swap, I'd look for a 3800 natually aspirated Series 3. They apparently produce the same amount of horses as the supercharged 3800 series 2.

Again, not sure if they would bolt up to the existing 4t65e or not.

(as you probably know... 3100 to 3800 supercharged in an SE)

it was actually a 3800 NA to a supercharged...but yeah, I'll be the first to tell you, the job is NOT fun. all the stupid little things that you have to change...and now I'm having problems with the car :banghead:

but yeah, I'd find out where the coolant is going. like i said previously..it may be something easier than you think :wink:

Ok, thank you very much you guys are all tremendous! I will try to answer all the q's. First, I am in Virginia, thank God I do not have to deal with the smog code of CA, but I will exhange the weather anytime, like tonight, we expect a little of the best nature can throw with the perfect elements and temps....

After this late winter reality check I will do all reccomendations eippermx enumerates for the engine oil and coolant.
The car has not been beaten the hell out of it, her first 8 years was used by my mom for daily work commute (13-17 miles with a lot stop and go) After that by me for mostly highway driving. I would say I do spirited driving but not abussive. Temp gauge never been above 240 and recently replaced all cooling sys components b/c cracked radiator.

The OP was a for a series 3 super chg. replacement yes, I have the NA Series 2, stock. Anyways, you have me almost convinced and I probably will stick to my stock powerplant and do a gasket replacement. So, upper plenum, valves covers too and which other ones shall I replace?

THANKS!!!! AF are Awesome!

cant forget the valve guide seats when you have it down. Also consider replacing the oil pan gasket (they can be problems on the 3800's, Mines leaking a little).

Not sure of the orientation of the timing cover gasket, but this one would also bbe a good choice to replace when its all tore down.

Here's a modified series II for $1200 if you decide to go that route.
http://www.wbodystore.com/grandprix/forged-95-l67-shortblock-used-p-230.html