Thread: New (to me) 2004 Comp G full engine rebuild and tons of questions

Hi guys, I recently purchased a 2004 Grand Prix GTP Comp G edition. Great looking car (body wise) but the engine is trashed. When I bought the car I intended on rebuilding the engine but as I've progressed, multiple issues have arisen. The first issue is after I took the heads to a machine shop to have them worked they found cracks between the intake and exhaust ports on both heads. I wasn't planning on upgrading them but if I'm going to spend $700 on new heads, I decided its in my best interest to buy the best ones I can, within reason (around $1000). I'm looking for the most bang for my buck with these, I know ZZP offers some but its been a few years since I've been around GTP's and wasn't sure if there are better options available. While the engine was out I decided to preemptively take care of a slow shift from 2nd to 3rd by replacing the shift solenoids, pressure control solenoids and anything else that is moderately easy to replace, any advice or suggestions is appreciated. I'm also wanting to flush the radiator because I'm having the block vatted and don't want to put a pristine engine back into a gummed up cooling system, what are my options to clean the radiator thoroughly in my garage? I'm also wanting to clean the engine bay because its simply grotesque. I've heard people use oven cleaner but that it takes off the paint so other options would be greatly appreciated. I'm also having an issue with the ABS system throwing a million warnings (ABS/Brake/TCS) as soon as I start the car. I assume it will probably be a wheel speed sensor but again, if anyone has any experience with this, I'd thank ya. Lastly (from what I can remember right now, been studying all night), the e-brake is insanely hard to push. I'm a big guy (6' 5") and can only imagine its seized or the guy who owned it before me adjusted it or broke something to make it this way. Sorry for the long post but I've been working on it for close to a month now and all these problems have slowly come to my knowledge. I bought it from a guy 6 hours away from me and had to tow it back so I wasn't able to diagnose a lot of these problems and my go to GTP site went down apparently while I grew up (GTP World). Thank you for any and all help and I hope I put this in the right section.

Papajohnspimp

I give you credit for wanting to go through the entire engine and cooling system. With so many used low mileage take out engines available the easier/cheaper fix would've been to buy one and swap it in and be done with it. That's exactly what I did when I lost the roller of my engine that had 330K on it. I picked up a complete 57K engine and was back on the road.

It spun a rod bearing shortly after I picked it up. I was planning on having the block vatted and installing an all new crank and bearings, rings etc... It's going to cost $200 for the block to be cleaned, milled and checked for cracks.

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I would not bother with all the align bore and machining these motors need to MAYBE survive. It's not a chevy 350 where you can just throw bearing in the bottom end and have it live. Since you are in school you need to save all the $$ you can. With a good used motor, all new gaskets for the upper half and rear cover, coolant, alum. coolant elbows, etc. you will be into it for less than just the block work alone to rebuild it. And most of the heads in these motors have cracks between the valves. I'd run em anyway. Any L32 should work. 04-05 GTP, 06-07 GT. Might even be able to use the L67 longblock and just swap your GenV upper end on it.

I'd save the money on the alum. heads and get the rest instead. If you want it to be a reliable DD then you need to get it back up to spec and then go from there or you're just going to be breaking stuff and be back at square one. If you plan on doing a pulley drop and whatnot you're going to need the headers and a tune anyway. Just hate to see you go through a lot to get it back together and have something go wrong. And then the wife unit will be on your a** because it's all borked again, lol..

I picked up my complete motor for $450 on craigslist and it's now got almost 300K on it and it runs just fine. Granted I'm N/A but they are out there if you look. Maybe check LKQ, car-part.com, craigslist for used engines. As long as they haven't been eating coolant or modded without supporting mods I don't see why not. A lot of times you can find someone selling one that you can hear run beforehand. And rod knock on these is pretty easy to hear if it's junk.

If I was able to find an engine with low mileage and a decent warranty for $500 I would, absolutely. The issue is finding one that has good compression and seals. I'll call around today to see what my options are. It's solid advice, I just don't want to regret getting a used engine later on because then it's back up on jack stands taking time away from school.

I do find it interesting that no one says to get the heads lol. I figured there would be at least one person here that could vouch for them. I was talking about the CNC ported cast iron heads from ZZP, I wish I could afford the aluminum ones lol.

Any suggestions on how to clean the engine bay?

Thanks again guys


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I would only get the ported heads if I have to replace them and rebuild the engine I have. Any engine I buy from a JY however is going to need the LIM gasket replaced just as a precaution and finding a good warranty on a $500 engine is going to be near impossible.

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For cleaning the engine bay I use LA's Totally Awesome. Yellow liquid cleaner/degreaser. I just spray it on, let it sit, then hose it down. Anything left I respray and scrub with a brush and it comes right off. Will not eat paint but I don't let it set there forever either. It has cleaned the bay of my Bonneville that was loaded with oil from leaks when I got it, to the point where you couldn't see bolts in certain places, lol. Best of all it's inexpensive and can usually be found at Dollar General and places like that.

I didn't know that pull apart junkyards only sold running engines, I always thought that they bought junk cars from anyone and just let their customers figure out if they ran or not. Now that I say that, it sounds kinda ridiculous. I still think I should be cautious but it's worth a shot.

Thank you for the suggestion on the degreaser, I tried mean green years ago but it never cut through the muck so I had no clue what to use.

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I'm out in Oklahoma so the only thing degreaser will kill is the smell of disappointment at OU football today lol.

Scottydog, Well now I don't feel silly anymore, there's no way any yard around here in gonna sell me a Series 3 Supercharged for less than $1000 and honestly if I'm dropping that on a used engine, what's the harm in spending a little more to build a stout engine that's studded and ported? I understand that in the short term it seems foolish but a few hundred $$$ isn't worth my piece of mind. I've rebuilt several of these 3800's with new bearings and rings before. I feel like this gives me a better platform for modding down the road. Hopefully something changes and I find that diamond in the rough or needle in the haystack. It just doesn't seem worth it to risk for a couple hundred bucks.

On a side note, I've decided to block off the coolant that runs through the supercharger by tapping the coolant passages on the supercharger. Has anyone tried this before, meaning should I instead be blocking off the passages from the LIM?

I truly thank you all for your input and if anyone is selling a ZZP modular pulley system or TOGs let me know.

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