Hey guys, can someone tell me what year and engine range can go in a 99 gtp. My car is in the shop and I have a blown piston. I want the same motor exactly if possible, but in searching the junkyards I see a lot of Buick 3.8 SC's
around.

98-00 Regals and Grand Prixs use virtually identical drivetrains. There are many differences in 97 models that will make using one of those engines harder to install, and 01-03's have differences as well.

What are the differences in the 01-03's? Would a repair shop look to charge more for installing one of those, or are other parts required? The reason I'm asking is because I'm calling around to salvage yards and would like an idea what to look for. By the way, thanks for the info.

Why did a piston blow? What size pulley were you running?

The engine was all stock. About three weeks ago I went to pass a truck on the interstate and the car had no power whatsoever, and soon after that at WOT the engine would make a noise which the best way I can describe sounded like series of internal backfires, pretty loud actually. A few days later the engine developed a valve/lifter type knocking noise. At this point I checked all wires/plugs and found the plug wire on cylinder 4 had a heat damaged boot. The plug's gap in cyl 4 also for some reason was alot wider than the .060 the others were at. I changed the plug and wire, but nothing changed, and the car proceeded to run worse, with poor idle and no power at all.

My repair shop (which I trust) found a bad TPS switch, that the car was running really lean, and also found that the plug in cyl 4 was damaged from being hit by the piston. They ended up tearing down the engine and found damage to cyl 4, there was a whole bunch of metal shavings in it and in the exhaust pipe, and the cylinder wall in four looked scored.

I am waiting for the shop to get back to me, but they suspect that the shavings are from the supercharger. Wherever they are from I'm screwed.
What sucks is that I have owned this car since new, and have always maintained it with oil, fluids, tuneups, etc.

My options now are a Jasper engine with a 3 year warranty, $3800 installed, or a junkyard motor with 50k miles on it pulled from a 98 Regal, or one from a 01 Grand Prix with 59K on it. The junkyards both want $900 for the engines, superchargers included, and my shop will install for $800. I am probably going the junkyard route at this point, as almost $4000 for a $5000 car is not worth it. If the car wasn't in great shape otherwise, I'd just junk the whole thing and get something else. I'm open to advice from the forum members here as to what to do.

-Ed

Quick question, do you cheat and run 87 octane in this car? If so, that's what most likely took out cylinder 4.

It's funny you mention that, I always used 93 octane, BUT, my to appease my tight-fisted wife, I was gassing up at Kroger for the past year, which is a supermarket chain here in TN. I used to tell my wife that this gas was probably crap and not worth the extra 10 cents a gallon we were saving, but she like a lot of people are freaked out over the price of gas. So it WAS 93 octane (at least the pump said so) but it was cheap quality gas I bet.

Did you ever do anything with the supercharger oil? You know, add to it, change it?

If the SC was ripping its self apart you would not just have issues with Cylinder 4 in my eyes...

Also, by the time the SC rotors were doing that bad you would have heard some noise and would have been loosing boost...

Also just a note to let you know... When you felt the car get weak.... The PCM was seeing massive KR and pulling all of your timing to avoid the KR or try in an effort to kill off the KR..

I'd love to see a couple of pics of the Piston and the Cylinder..

The bad thing about a boosted car, say you had an injector that was not flowing as it should and that cylinder was running lean.... You stomp on it and boost ahoy we go.... And a bit the down the road the PCM picks up the KR and tries to get rid of it but can't... The next thing you know, there goes a Piston..

Jasper is a really good reman engine.... I'd have to say they are just about the best in the business...

But for the $$$.... I too would go with the 50k motor.. When you get the car back you'll want to make sure everything right down to the injectors is functioning as it should.. And the M90 SC... Make sure you get the old one.. You can have it rebuilt if its not damaged for use at a later date...

Wish you the best of luck with the new used motor..:cool:

The engine had about 105K when the piston blew. Around 65K I changed
the S/C coupler as I was getting the rattling noise from the original coupler.
I checked the fluid in the early spring of this year (about 95K at the time) and it was up to the fill hole.

As far as the s/c, the only thing I noticed was that lately it seemd the s/c was kicking in a lot earlier and harder than it was in the past, by that I mean going up this hill by my house, I noticed the boost meter almost to the maximum, but the s/c wasn't or couldn't put out the power to move the car.
In other words, the boost meter was showing a lot of boost being generated, but the car wasn't really going anywhere near that fast up the hill.

If I can get pix I will, as I have to make arrangemants to get the motor to the shop and will be dropping it off to them this week.

To JRS3800 thanks for the good wishes, and thanks to the other posters for your input.

To update, I just got the car back today. I bought the 50k 98 Regal motor, cost $800, with an extra 80 to extend the warranty from 30 days to 6 months. I extended the warranty because the engine had been idle for almost three years, but the oil looked clean and the salvage yard checked that it turned freely. The shop charged $850 for the engine install, and in getting the motor up and running changed the water pump, thermostat, throttle body gasket, all oils/anti-freeze, put back the freon, and some vacuum lines and elbows. They also discovered a clogged cat convertor, and changed that out. When the smoke cleared, including the engine, final cost = $2200 = OUCH!

The good news though is the car seems to be fine. Idles super smooth, and all the power it used to have feels like its back, although I will be gentle on it for awhile since the motor's been down for some time. I have the old S/C, and will look to get it rebuilt so I have an extra or to sell. Some of the fins
do show signs of scuffing from rubbing against the SC innards. Pics here:

http://www.flickr.com/photos/meathead1/sets/72157606981508025/

http://www.flickr.com/photos/meathead1/sets/72157606981508025/
http://www.flickr.com/photos/meathead1/sets/72157606981508025/

did you keep any sensors or things off the old motor?

how about the heads or LIM?

Unless there was a core charge, the old motor is yours and your free to sell the parts to recover the costs....

No sense giving it to the repair shop, they are just going to use it in parts for other cars.