Thread: overheating - loss of power

First of all I left the lights on at a store, killed the battery I got a jump and was gonna drive the car 25 - 30 miles to charge the battery back up, was driving on the freeway, well after about 10 miles the temp was reading hot, then normal then hot again, and then the power dropped, I could not go faster then 50 mph, I was trying to make it to the next exit, then the car just died, pulled off the road lifted the hood, and steam was comming out, had car towed home, I heard that when this car gets hot the computer would shut things down and that could be the cause of power loss, I changed the thermostat, and noticed the radiater cap was rusted up which may be why the resivoir was allways full. Any truth to the computer shuting down componants and caused the power loss, or do you think I blew a gasket, no water in oil.

Originally Posted by grand prix newb

First of all I left the lights on at a store, killed the battery I got a jump and was gonna drive the car 25 - 30 miles to charge the battery back up, was driving on the freeway, well after about 10 miles the temp was reading hot, then normal then hot again, and then the power dropped, I could not go faster then 50 mph, I was trying to make it to the next exit, then the car just died, pulled off the road lifted the hood, and steam was comming out, had car towed home, I heard that when this car gets hot the computer would shut things down and that could be the cause of power loss, I changed the thermostat, and noticed the radiater cap was rusted up which may be why the resivoir was allways full. Any truth to the computer shuting down componants and caused the power loss, or do you think I blew a gasket, no water in oil.

I replaced the thermostat, and radiator cap refilled radiater w/coolant, started car, engine shakes has a tick and the service engine light is on.
engine temperture gauge read hot again, fan's came on but the temperture never went down. replaced water pump a few months ago, its not howling or loosing any water from the drip whole, but, does that mean it's a good water puimp? how hard is it to do the hg on these?
Anyone do one on the 3800 series 2 engine, is it better to buy the head gasket set or just the head gasket?
should I be worried about a cracked head?
allthough there is no water in the oil, no steam coming out the engine or tail pipe.

Originally Posted by grand prix newb

First of all I left the lights on at a store, killed the battery I got a jump and was gonna drive the car 25 - 30 miles to charge the battery back up, was driving on the freeway, well after about 10 miles the temp was reading hot, then normal then hot again, and then the power dropped, I could not go faster then 50 mph, I was trying to make it to the next exit, then the car just died, pulled off the road lifted the hood, and steam was comming out, had car towed home, I heard that when this car gets hot the computer would shut things down and that could be the cause of power loss, I changed the thermostat, and noticed the radiater cap was rusted up which may be why the resivoir was allways full. Any truth to the computer shuting down componants and caused the power loss, or do you think I blew a gasket, no water in oil.

Originally Posted by grand prix newb

I replaced the thermostat, and radiator cap refilled radiater w/coolant, started car, engine shakes has a tick and the service engine light is on.
engine temperture gauge read hot again, fan's came on but the temperture never went down. replaced water pump a few months ago, its not howling or loosing any water from the drip whole, but, does that mean it's a good water puimp? how hard is it to do the hg on these?
Anyone do one on the 3800 series 2 engine, is it better to buy the head gasket set or just the head gasket?
should I be worried about a cracked head?
allthough there is no water in the oil, no steam coming out the engine or tail pipe.

after filling radiater and resivoir,before it got hot the resivoir started leaking coolant out the overfill whole, is that water pump or head gasket?

Got it to stop over heating by bleeeding the system, but check engine light is still flashing and idle's real rough when I push the throttle to about3000 rpm's it really sounds rough and purges, hg maybe warped head, intake leak. what else could get ****ed up from over heating> anybody got anything?

Originally Posted by ASCStinger

check compression? you can also try pressure testing the cooling system, but I'll bet your lim gasket's leaking at the least. The coolant can get into the cylinders and foul up the plugs, or even hydrolock them in severe cases. Also, any oil/coolant burnt will foul the O2 sensors and plug up the cat, which would also cause the car to run like crap.

Thanks bud,

I got the scaneer, and it read as follows:
1 of 2 -
code P0303, and undernieth code it says Cyldinder #3 Misfire

2 of 2- (Same)
code P0303, and undernieth code it says Cyldinder #3 Misfire,

Why did it say the same code twice? Is it because of two different problems that caused the P0303 Code
Thanks

Checked spark plug it was a little loose, had black soot on it where combustion was leaking out onto it, was wet with gas, checked, and verified there was spark, will change plugs and wires soon. and update.

Hey if there was a air leak from the intake or head would there have been a different code other then P0303 also?

Originally Posted by ASCStinger

the first is a pending code, second is a code currently set in the computer (AKA there has been a misfire problem in the past and it is also currently misfiring

Originally Posted by grand prix newb

Checked spark plug it was a little loose, had black soot on it where combustion was leaking out onto it, was wet with gas, checked, and verified there was spark, will change plugs and wires soon. and update.

Hey if there was a air leak from the intake or head would there have been a different code other then P0303 also?

Kool changed the oil, while waiting for funds to jump up, and I was under car and thinking, and I brought myself back to when I popped off the #3 plug wire from coil, and remembered the coil prong was rusty collored, so I checked the other coil prongs and they were all shiny, so there's my Cylinder #3 misfire prob.

The first P0303 was A loose #3 spark plug, and the second was the coil.

Then I thought about when I reved the engine and it would bog out, and I thought it was a massive air leak somewhere, I took car for a ride around the block and the power was good and strong, so can't be the head or head gasket, or intake.
so in park I reved it from inside the vehicle, and seen it only bogged at around 4000 rpm's, yes it's suppose to, thats the limiter kicking in, what a relief I will get a new coil and update later, thanks for all the help gentlemen.
__________________

Originally Posted by JayAz

I had a similar issue last summer with my 2000 GT. It was slowly leaking coolant over time (my low coolant sensor doesnt work right).
Engine temp just jumped up to max while on the freeway.
I managed to add coolant, and it seemed 'ok' for another month.

There is a plastic 90 degree elbow (newer models have 2 plastic elbows) on that was cracked and deteriorated. It is located on the drive belt tensioner, which is under the alternator.
Get these elbow(s) replaced, part cost is about $11 each from the dealer. It is called a upper and lower thermostat bypass pipe assembly (same part # for both). 1 hour DIY project.

The overheating though, warped my UIM Plenum (I have a N/A, VIN K).
Eventually (month later), coolant leaked into my engine. $1180 went to my local shop to have it fixed.

Thanks I noticed coolant coming out of that elbow and yea both ends of it were corroded and gone, replaced, I too think my Uim is warped, or blew the gasket.
but she's fixable. I am sure I can do it my self, tore apart many engines, time for this one I guese.

Originally Posted by JayAz

I had a similar issue last summer with my 2000 GT. It was slowly leaking coolant over time (my low coolant sensor doesnt work right).
Engine temp just jumped up to max while on the freeway.
I managed to add coolant, and it seemed 'ok' for another month.

There is a plastic 90 degree elbow (newer models have 2 plastic elbows) on that was cracked and deteriorated. It is located on the drive belt tensioner, which is under the alternator.
Get these elbow(s) replaced, part cost is about $11 each from the dealer. It is called a upper and lower thermostat bypass pipe assembly (same part # for both). 1 hour DIY project.

The overheating though, warped my UIM Plenum (I have a N/A, VIN K).
Eventually (month later), coolant leaked into my engine. $1180 went to my local shop to have it fixed.

Originally Posted by grand prix newb

Thanks I noticed coolant coming out of that elbow and yea both ends of it were corroded and gone, replaced, I too think my Uim is warped, or blew the gasket.
but she's fixable. I am sure I can do it my self, tore apart many engines, time for this one I guese.

How did you come to determining that the UIM Plenum was warped, compression check? or?
And was coolant noticable in your oil?
Cause I see no coolant in oil.

Originally Posted by jtsheppar

I think this is the problem I have... My upper/lower thermostat bypass pipe assembly ruptured over the weekend, thankfully right when I pulled into my driveway. I'm looking at it again tomorrow, but from what I could see tonight, it really only looks like I could replace it by pulling off the belts, tensioner, etc. (Not a 1 hour DIY project - least of ways for me). The tube is hard plastic, so it doesn't look like it could fit without pulling out some of the components off of the belts.

Is there a step-by-step someone knows of or an easier way to do it than pulling all of this off?

Much appreciated! I need to get it fixed ASAP.

Sorry no easy way, just have to remove belt, remove alternator, unbolt the tentioner housing and pull off, the plastic elbow is inside there, when you remove the elbow make sure there are no broken pieces inside, they usually corrode and break apart in there.
That part(tentioner housing) with the hoses sticking out is what the elbow is in,you see the end of elbow on the right side. sorry no better pics.

To answer one of your original questions, I know my Grand Prix GTP (97) has what GM calls a "Limp-Home mode". If the coolant temperature reaches critical levels, the computer will shut off half the cylindars for a while to let the others cool off. After a while the computer will turn the dead cylindars back on and turn off the ones that had been running to cool them off. You don't want to drive more than 50 miles in this condition or bad things happen. Obviously there is a serious reduction in power when in limp-home mode. a

Sounds like you did suffer damage though as you have coolant in the oil. You could have damage to head or LIM gaskets or even cracked heads. Run a compression check if you haven't already and hopefully you'll find the issue there. If not, it may be time to tear down the engine to find the problem.

Next time, when the SES light comes on and you see the temp rising, pull over and let the engine cool off. It's much cheaper that way. Also, a flashing SES light always means that you have a missfire.

Originally Posted by Robotech

To answer one of your original questions, I know my Grand Prix GTP (97) has what GM calls a "Limp-Home mode". If the coolant temperature reaches critical levels, the computer will shut off half the cylindars for a while to let the others cool off. After a while the computer will turn the dead cylindars back on and turn off the ones that had been running to cool them off. You don't want to drive more than 50 miles in this condition or bad things happen. Obviously there is a serious reduction in power when in limp-home mode. a

Sounds like you did suffer damage though as you have coolant in the oil. You could have damage to head or LIM gaskets or even cracked heads. Run a compression check if you haven't already and hopefully you'll find the issue there. If not, it may be time to tear down the engine to find the problem.

Next time, when the SES light comes on and you see the temp rising, pull over and let the engine cool off. It's much cheaper that way. Also, a flashing SES light always means that you have a missfire.

Thanks for the info, still havent done a compression test on it yet, a few mobile mechanics say it sounds like a head gasket, and from there expierience with 3800's it probobly is, and the mechanics at local shops say it sounds like lim gasket and the 3800's rarely have head or head gasket problems. so I will narrow it down with the compression tes next weekend. would of been sooner but I have two other vehicles, and low funds, so no hurry, can't wait though, I miss the GP.

Well first of all Merry Chrismas and/or Happy Holidays to all!!!
I finally got a good compression tester, strap to hold engine forward etc. I want to do a compression test, manual says should be done at normal operating temperture, don't want to run vehicle do to water in oil tank, Can't I just do the compression test on a cold engine and get enough reading to tell if my hg is bad or heads are cracked, or should I just change the oil, and run it for 5 - 10 min to get it at operating tempature. The oil stick isn't terribly white, just got some white bubbles in it, its not thick at the top oor anything like that, so wonder if I can run it like that for 5-10 min with out hurting engine any more Please let me know what you think.
Thanks.

Originally Posted by grand prix newb

Thanks for the info, still havent done a compression test on it yet, a few mobile mechanics say it sounds like a head gasket, and from there expierience with 3800's it probobly is, and the mechanics at local shops say it sounds like lim gasket and the 3800's rarely have head or head gasket problems. so I will narrow it down with the compression tes next weekend. would of been sooner but I have two other vehicles, and low funds, so no hurry, can't wait though, I miss the GP.

Originally Posted by grand prix newb

Well first of all Merry Chrismas and/or Happy Holidays to all!!!
I finally got a good compression tester, strap to hold engine forward etc. I want to do a compression test, manual says should be done at normal operating temperture, don't want to run vehicle do to water getting into oil tank, Can't I just do the compression test on a cold engine and get enough reading to tell if my hg is bad or heads are cracked, or should I just change the oil, and run it for 5 - 10 min to get it at operating tempature. The oil stick isn't terribly white, just got some white bubbles in it, its not thick at the top oor anything like that, so wonder if I can run it like that for 5-10 min with out hurting engine any more Please let me know what you think.
Thanks.

Nevermind I better do the right/safe thing and just change the oil & filter first, and then get it to operating temperture to do the compression test.