Ok, so I have this Pontiac Grand Prix 3.1 V-6 that seemed to be a really great car for the first year, but then all the windows started to break down multiple times, the key got stuck in the ignition 2 different times over the course of a 4 year span. But it gets worse, as I get the car paid off and I have about 80,000 miles on it, the lower intake manifold gasket starts to leak. So I spent about $500 in parts to replace the gaskets, coolant, radiator cap, temp sensor and thermostat. but it gets even worse. As the problems seem to ease up and thinking that I've got the problems under control, about 18,000 miles later, the car starts to overheat on my wife. It spit/sputtered as she pulled up to the house and thankfully she killed the engine before the engine seized up. When I checked the oil dip stick I found all my coolant had flushed into oil. So now it's safe to assume my lower intake gasket blew out again, but this time internally. Another set back that cost me $800 more. It would have been considerably more had I not done the work myself the second time around.

One thing I did find out was that there have been numerous people locally that have dealt with this same problem on the early model 3.1 v-6 due to the manufacturer using a hard plastic gasket. They have since come up with a steal "fix" gasket that you can purchase at your local automotive parts stores. Remember though, this engine wasn't just used in the Grand Prix models, it was used in other GM cars as well. Example: Bonneville, Monte Carlo, Lumina, etc.

Word of advice: Avoid all 3.1L V-6 engine possessing cars!

I bought my car in July 2008 from a dealership in Charlotte, NC. It had just over 85,000 miles on it. After about 8 months I began to notice that it was overheating alot and temporarily losing horsepower. The first time it happened I was with my fiancee' in West Virginia to visit her family I was so embarrassed. I checked my coolant level and it was extremely low so I added new coolant. It solved the problem for a while, but eventually it came back. So' I added more coolant again assuming since it was so low last time it just went through the coolant i just added. It was all good for a couple of months, then it came back. It was strange though b/c it would over heat at idle in park, but when it was in park and I pressed the gas, it would cool down which led me to several different conclusions. I recently flushed my radiator myself and got rid of the Dexcool and all traces of it that was there and replaced it with green coolant. I also hand to replace the coolant hose b/c it cracked and leaked coolant everywhere (it looked to be corroded on the inside of the hose). I haven't had the same problem recently and it's been running very cool and great, I'm still keeping a close eye on it though. I still want to flush it 1 more time though to make sure its clean and run some radiator sealant through it to make sure there are no problems on that end. Total cost of this fix for a do-it-yourselfer like myself is about $30-$40 dollars and it is a very easy fix just make sure you have a full evening to do it. The bottom line is that Dexcool is sh*tty and possibly corrosive so if I were you I would flush that sh*t out and replace it I've heard some horror stories about it. My car has almost 113,000 miles on it and is running great, I thank God for that. You just have to be proactive in catching these problems early, do your research and ask alot of different mechanics and even some knowledgeable friends. 90% of common problems on this vehicle can be fixed cheap and easy and you don't even have to know much about cars to fix them, I don't even know that much about cars myself. I would recommend finding the mechanic's manual for this vehicle and when you do your research and diagnose the problem early on, fix it yourself. It may take more time, but you will save a ridiculous amount of $.

I was curious as to how many others were having the same problem I was diagnosed with concerning my car overheating. I am as surprised as others as to why "GM/Pontiac" has not done an recall on this problem with the intake exhaust manifold. My car is at the point where is it overheating and will not perform. I have spent an enormous amount of money on this car since October 2008, now I am hit with another huge bill of $585 to repair this intake manifold exhaust. On this same week, I just replaced my thermostat, water pump and serpentine belt. At the beginning of this month I had to replace the catalytic converter...this was horrible. I was hit with an repair of $920 by Pro Trans to do this job...I did eventually get this bill down to $552, he still ripped me off!!!! But this intake manifold gasket is really a pain, you can't see any leakage, but you can smell it, I have no heat and it is really a prayer that I get to where I need to get to driving like this. The one good thing out of this, I have found repair shop that will repair my car much less than what I have read here....$585.

So far to date, the problems with my car....hub bearings, no heat, heater blower, intake manifold gasket, catalytic converter and clock/radio display will not display going on over a year now. This car has been great up until now, I do feel safe in this car, it is big and sturdy!!! But I can't believe the irresponsible actions of GM/PONTIAC with this known problem with this car...INTAKE MANIFOLD GASKET