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Discussion Starter #1 (Edited)
I have just last monday purchased a 05 yellow jacket m6.I bought it in mckenny TX.It was used a BOB TOMES ford.When I drove it home it did fine.Now every time I am sitting still idleing it will start heating up.Or at least it says it is.Then I found out some of the 05's had gauge cluster problem.To my understanding alot of the 04's had this problem.This morning I went out and cranked it and left it running while I was wipeing it down.Then all of a sudden It starts overheating,antifreze leaking out.Then it cooled down.So today after letting it sit for several hours.If you crank it and let it idle,heat gauge will come up then it will cool down when the thermestat opens.I know the thermestat is opening now because I had the heater on.But anyway It will never act up going down the road just siting and idleing.Heat gauge will come up and show hot and peg out on the gauge.Then if you rev it up it will go back down.The fans come on and all.The longer you let it idle the more it will do this ever now and then.I am suppose to take back to pontiac tues.Any body have any suggestions.I need all of your knowledge.HELP:confused
 

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YellowGOAT1 said:
I have just last monday purchased a 05 yellow jacket m6.I bought it in mckenny TX.It was used a BOB TOMES ford.When I drove it home it did fine.Now every time I am sitting still idleing it will start heating up.Or at least it says it is.Then I found out some of the 05's had gauge cluster problem.To my understanding alot of the 04's had this problem.This morning I went out and cranked it and left it running while I was wipeing it down.Then all of a sudden It starts overheating,antifreze leaking out.Then it cooled down.So today after letting it sit for several hours.If you crank it and let it idle,heat gauge will come up then it will cool down when the thermestat opens.I know the thermestat is opening now because I had the heater on.But anyway It will never act up going down the road just siting and idleing.Heat gauge will come up and show hot and peg out on the gauge.Then if you rev it up it will go back down.The fans come on and all.The longer you let it idle the more it will do this ever now and then.I am suppose to take back to pontiac tues.Any body have any suggestions.I need all of your knowledge.HELP:confused

Classic case of the sticking thermostat.
 

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Sounds like the thermostat but could be something else. Have it towed (not driven) back to a Pontiac dealership for repair. I'm sure it's still under warranty..........

JET
 

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Discussion Starter #5 (Edited)
I think the stat was stuck once.But if you drive down the road the heat gauge will peg out then go back down to cool.It does this back and forth.I know that is not the stat.But it seems to show heating up when your cruising at a steady speed or idleing.But as soon as you accelerate the gauge drops.Also when the car is showing hot, it has no pressure on hoses when showing hot.I think the gauge cluster is faulty.This is also what pontiac has already told me.The only thing that throws me off is the fans are kickin on and off.In other words when it is showing hot the fans are kicking on.Unless the fans also read off the computer when the gauges are showing hot.Pontiac said don't worry the car is not getting hot,its just a bad gauge cluster.They also said they have documented this.Its going back tuesday.So I will fill them in.I think they sould put in a new stat and gauge cluster.
 

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You did say in your original post that it leaked out coolant. If the gauge says it's hot, and coolant is leaking out, you can bet your bootey that it's HOT. If your coolant doesn't leak and the coolant level stays full, then it's likely a bad temp sender, bad connection to the sensor or a faulty gauge.
 

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Have your car taken to the dealer via flat bed. As for your potential problem, everybody's already hit on all of them...

The thermostat definitely sounds screwed up. It may be stuck closed -- or partially sticking. Either way, you're going to get water temperature fluctuations -- and the fans are going to be kicking on/off.

The water pump may be prematurely failing -- so you're getting inconsistent circulation. If, for some reason, the pump slows way down, the coolant in the engine is going to go way up. You never know, if might be the drive belt or something. Doubt this is the case.

While there has been a problem with the gauges sending wacky readings, such as pegging the coolant temp -- I just don't think that's the issue here. When this happens, the temp, speedo and everything else kind of freak out for a couple of seconds -- then it goes back to normal. And coolant definitely doesn't leak everywhere.

It could also be some kind of sensor that went on the fritz, too. You know with all the electronics cars have these days. Had a Mustang that started smoking like a damn bus driving home from work -- and it was an ECM that crapped out after something like a year.

The good news is that the car has excellent engine safety protection features built in -- so your engine, with very close to absolute certainty, is fine.

Any good tech is going to approach your problem in a methodical manner -- eliminating the usual suspects until something definitive is found. For anyone to leap straight to the conclusion that it's the gauge really isn't doing their job. Talk to a couple of service managers at nearby dealers first -- find out what their approach is -- then go to the one who sounds like they'll take their time and get this problem solved on the first trip.

Best of luck to you. Overall, the GTO has excellent build quality -- so once these bugs are worked out -- you'll be loving your new car.
 

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Discussion Starter #8
Yes,my car did leak antifreeze once.But I have drove the car the last two days.The car runs great it has never leaked out anything again.Their is only a few things it could be a thermestat,tempature sensor,or gauge cluster.I am not the best mechanic in the world but I did do it for a living for several years.And also built several muscle cars.I just didn't know if you guys have had similar problems.I appreciate all yall's help.The last two days the car heat gauge will show hot for a second then go right back down to cool.It does't even have pressure on the hoses.But since I filled it up with gas it has stop moving up and down as much(heat gauge).I am taking it in in the morning.But I know the the car is really not running hot.
 

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Discussion Starter #9
I feel like a complete idiot.I took my car to the dealer today.I left it about 3 to 4 hours.Come to find out the radiator cap is hidden under a cover.I thought the over fill was where you add the water or antifreeze.These guys at the dealership didn't even know at first.They said it took them a little while to figure out where it was also.All that was wrong was low on water.All the work I have done on cars threw the years,and this bit me.But the first time I took it in they told me that it was probably the gauge cluster.I never thought anything else about it.But good news the car runs great and nothing else is wrong.Thanks for all of you guys input.
 

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YellowGOAT1 said:
I feel like a complete idiot.I took my car to the dealer today.I left it about 3 to 4 hours.Come to find out the radiator cap is hidden under a cover.I thought the over fill was where you add the water or antifreeze.These guys at the dealership didn't even know at first.They said it took them a little while to figure out where it was also.All that was wrong was low on water.All the work I have done on cars threw the years,and this bit me.But the first time I took it in they told me that it was probably the gauge cluster.I never thought anything else about it.But good news the car runs great and nothing else is wrong.Thanks for all of you guys input.

Glad you found the cause of the high temp readings. If I were you, I would monitor that coolant level like a hawk. That puppy (or should I say Goat) should not have gotten low on coolant unless it came from the factory like that. My guess is that you could have a slight leak around a radiator hose (maybe needs tightening) or a minor leak elsewhere. Keep an eye on it and if the coolant level starts getting low again, by all means take it to the dealer and have them find where that coolant is going.

Anytime a engine overheats, some damage has been done, however slight. A repeat performance is definately something you don't want to happen if you intend on keeping the car until it is a high miler.

Enjoy the Goat and be safe - Jim
 

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Discussion Starter #11
Thanks,They did pressure test the cooling system for leaks today.They also said it might been low from when it was first serviced.Believe me I am going to watch everything on this car.Thanks God bless.
 
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