So the teardown of the GXP I got for $1000 bucks has begun. Lot's and lots of neglect under the hood of this car, oil leaks everywhere, damaged harness, and broken loom everywhere, gonna be alot of cleanup.

I was speculative about what was going with the transmission, the guy had receipts for a 2300 dollar rebuild of the trans, but the trans looks completely untouched. I was convinced that the torque converter was going to be the source of t he problem, but after finding this....



I know that at least something has been done to the trans, what exactly, I am not sure. The symptoms I am experiencing was accurately described by TEP...

Loss of movement, Possible whine noise:

Another problem that we see often with these models is complete loss of movement after driving and wont move in any shifter range.

Very common on the 2005-2009 LS4 V8 models and factory transmissions with the 258mm torque converters.

Shutting the vehicle off for a short period of time and restarting may allow it to move again but only for a very short distance. Typically the source of this is a plugged filter due to torque converter and/or torque converter clutch failure and the debris finds its way to the pan and gets sucked up into the filter. Dropping the lower pan for inspecition often shows heavy amounts of dark colored debris in the pan. If you remove the filter and cut it open you will find the debris trapped in here also. Excessive clutch and geartrain damage can also cause the filter to become plugged up but not as common to see.

The problem can be caused by excessive TCC apply pressure and is a problem with original or factory and aftermarket rebuilt transmissions. Sonnax has a few parts to address this problem and we have used them for a long time with great success. Unfortunately once the damage is done it often means a full rebuild as there will be lots of debris contamination throughout the transmission and must be cleaned to prevent future problems. Replacing the torque converter with a stock or reman stock style torque converter will not correct this problem and will be a short lived solution.

However with this obviously new converter, that looks identical to the converter I just bought from TEP, im more inclined to think that they never bothered to rebuild the trans at all, and pulled a trans from the junkyard and just charged the guy for a $2300 dollar rebuild. The other shoddy repair work is a dead give away of a shadetree mechanic.

GM did me a solid and put a completely independent positive and negative main harness which I was able to pull out, I will have to redo this entire section as the positive side was almost cut in half by the belt drive from again, shoddy repair work.



Should have it out with the trans by the weekend and I can further delve into the condition of the motor and trans. Gonna be ordering the TEP stage 1 master kit, 3.69 gear set with the 7/8" chain drive, and I had a OEM new input shaft from GM sent out to CryoPlus for cryotreating and tempering for some additional strength, total cost is about 50 bucks for that including the cost of the new input shaft. Should provide adequate insurance for my goals which wont be much over 300whp. I see no reason to spend $500 dollars on a 300M Chromoly input shaft just yet.

 

Wow that looks horrible, sorry to say

 

Oh its a mess, did another two hours worth of work tonight, found out why the previous owner said it was overheating.

 

i wonder how many times its been severly overheated. Always the thought that would be in the back of my head
Some times you can repair small cracks by doing plastic soldering, but uh.... thats a huge freakin crack lol

 

Not entirely sure what lead up to that failure, but the way t he guy described it to me, he said he had been having issues with the trans not wanting to go into gear, he took it down the street from his apartment, and it stopped moving in anything but reverse, so he threw it in reverse and backed it up down the street, half way down the street it started smoking and overheating and by the time he got back it was spraying coolant everywhere. There's no residual damage from a massive meltdown like I've seen some people do, last job i did on a camry, guy drove it home from work with the needle pegged, it was so bad that it melted most of the sensors on the car. lol What scares me is the fact that the damn thing blew out like t hat, ive never seen them explode except in a case of a head gasket failure, but it doesnt have any evidence of a bad head gasket.

 

Couldn't see the crack right away on my phone till i turned the brightness up . Holy frig. Lol. Wonder how hot it would have to get to cause that. U pullin the heads off ? Hopefully u get lucky here. Still should be way ahead on this one !

 

No idea, i've only ever seen failures like that when head gaskets pop, but the head gaskets seem fine on this car. Once its out im gonna do a leakdown test on the stand, if it seems like it has excessive leakdown then ill probably wind up doing more then just the heads. Time will tell once the heads come off and I have a chance to inspect the cylinders.

 

Battled some more parts today, this thing is ****** disgusting, the harness is in **** shape right now, the knock sensor wires were so brittle from being exposed to heat that they broke off in my hand when i went to remove the connector. So ill be buying a replacement section for that. Working on seperating the harness from the car so i can inspect it more thoroughly and then re-loom it. Half tempted to just send it to rywire.

 

You sure its the wire , or just the loom around it. The loom will become brittle. i used Heat Shielding insulated tape and filled it with high temp clear silicone

 

oh its the wire alright lol it broke off right at the connector, the loom is gone across most of the harness on that lower portion around the exhaust, and sections of the top by the belt. Previous owner told me they replaced the fuse block in an attempt to repair the issues with the EBCM which I fixed, def has a new fuse block, but they tore up all the loom and left the connector at the fuse block hanging out. The oil pan gasket is puking oil, as are the valve cover gaskets on the back side, and it looks like someone used RTV all over the water pump manifold. Also really bad oil leaking around the oil filter. Gonna need a massive cleaning.

 

The epic disaster that is unfolding with this car is incredible. Not only were most of the bolts loose from previous mechanical work, they left one of the bellhousing bolts out and never bothered to put it back in, and better yet, LEFT THE FRONT MOTOR MOUNT UNBOLTED FROM THE CRADLE. How this guy didnt notice the engine rocking around in there is amazing. The transmission that he paid to be rebuilt looks completely untouched, we are theorizing they put a junkyard trans and a new converter in it and charged him the 2300 bucks for a rebuild. They claimed they replaced the harmonic balancer for 1100 bucks, its the original balancer, and the rubber is dryrotted and cracked. The engine is leaking oil everywhere, but, he didnt lie about using full synthetic in there from day one, inside of the engine is spotlessly clean. Leakdown test showed good results on the stand, I know its supposed to be hot when you do that test but I just wanted a general idea of what the condition of the engine was like before I started tearing it down, results were better then I could hope for. Less then 10% on most cylinders, with some cylinders coming in at under 5% leakdown, even with it cold. Only one cylinder had an issue that presented a problem, and it was a bad exhaust seat and it was blowing by most of the pressure. Seem'ed like all the exhaust seats had some bit of leakage but there was virtually zero blow by from the rings or valve steam seals. So I feel very good about reusing the bottom end and just doing head gaskets and reconditioned heads.

Trans is definitely the source of the problem, fluid is burnt, smells awful and looks like ****. Will know more once I get the pan off.

 

game over man, game over

 

Ive always wondered if it was hard to pull it out the top, did you have to do anything major to get it out the top ? Did you undo the A.C. as well ?

 

u still ahead of game,now u were gonna do this anyway and now u get to build your way,heads don't look bad deck them get some more compression while u at it,like to see how much u spend as to what one like u build would have cost,we all do this anyway new trans i mean some of us 3 times uh em,keep strokin man lol

 

Aside from removing the fuse block, and getting most of the accessory drive out of the way before hand, the only thing that really holds you up is the crank pulley bolt, so you have to get the front mount out of the way, lower the engine down, take the crank pulley bolt out, and then as your coming back up have someone maintain constant pressure on the trans side to keep the flywheel clear, other then that, had just enough clearance to come up without any issues. First time around is always a challenge as your hitting stuff you cant see.

Honestly though the hardest part about removing this engine is the rear bolts that hold it to the trans. While you can reach them through the passenger side wheel well, you gotta have some man strength to get t hose ******* off with how little leverage you have on them. Fortunately with the help of a really tall friend of mine, he was able to get them out, as my arms were just too damn short to even reach them without getting hung up under the wheel well. lol AC is amazingly well placed on this car, they route the lines around the entire length of the engine bay around the trans side, and it just allows you to take the compressor, and sit it right on the front of the engine cradle between the rad support with little to no effort at all. Ill have to take a picture of it tomorrow for you.

Way ahead of the game, only thing holding me up budget wise is most of my money right now is tied up in me getting my cobalt sold. Been a month of total bullshit offers on the car, so just waiting for the right buyer to come along for the car and then a huge purchase is going to be made.

With the bottom end of the motor being solid as ****, only thing I am going to do is remove the heads and have them reconditioned. Looking at a 3 angle valve job and ill probably do a 45* back cut on the valves as well. LS6 valve springs, and new valve stem seals will round out the package. I am getting a vinci ultra torque (crane 1449041) cam specced through a friend who does cams, 210/218 with .551 lift and a 116 LSA. The 5.3 truck guys seem to love this cam and the dynos that I saw for it were impressive, and should make for a fantastic street cam for this car with a stock stall which will maintain my drivability and gas mileage for the most part. Friend of mine has a LS1 intake manifold laying around his house so I am going to do the conversion for that along with a set of OBX headers and a custom catted downpipe to keep the noise levels low.

The trans will probably wind up being the stage 1 kit from TEP along with the 3.29 gears and the 7/8" chain. Which should give me a decent bump in acceleration over the 2.93's but still maintain a nice low cruising RPM at 80mph.

It's going to need brakes and probably front control arms as well, so raybestos EHT front and rear brake pads, centric stoptech power alloy drilled rotors (see pic below) and a set of ZZP SS lines and ill probably do the 5th brake line conversion to a hard line. ( http://www.grandprixforums.net/threa...uot-solution-6 )

 

I've pulled my transmission out the bottom, took bout 8 hours my first try. But I hate rolling around on the ground.I'd much rather pull the engine out the top if I ever had to anyways, thanks

 

Od have to check again but I was pretty sure 04+ GPS have a hard line there

 

Ill take a look at it today, didnt have a chance to take a look at the lines yet.

 

Not trying to help you spend your money but that motor is out, I would at least have a look at those bearings. Sounds like you have some mods coming, and with 100k on the motor already it may or may not be ok depending on how good the previous owner was with his maintenance. Not sure how much rings and bearings would run but its something to consider. Just my 2 cents. Great work so far! I hope someday to be going right thru mine as well when it need it.

 

Couple hundred additional dollars for rings and bearings, as well as machine work to the block. I could probably get away with honing it myself but I don't have a hone that fits this size bore unfortunately which means I would have to buy the tool on top of that. I am going to do a visual inspection soon as i pull the heads off, don't know if im going to pull the crank out though. Ill have to see what kind of wear and tear I see in there visually on other components to see if it warrants going that deep. Given how clean the engine is internally and the track record of full synthetic oil changes from day 1, this engine is probably the best i have seen internally out of all of the engines I have done in the past 10 years. While he may have gotten beat with other mechanical work, he was at the very least meticulous about getting his maintenance done regularly.