We changed the radiator,water pump, and the thermostat and the temp still goes hot when you come to a stop and goes down when driving at 55 , but still no heat have blessed over and over very frustrated!! It is a 2002 Pontiac grand prix se...... please help me
Sounds like your radiator fan is not working.
Did you bleed the air out of the cooling system? On the 3.8L (3800 V6) there's a bleeder screw on the thermostat housing. HTH. -Jim
Yes have bleed many times had to pull over 4 times trying to get home and bleed again I know there are two bleeders... the fan I beloved is working it does come on.. how to I check to see if it is working properly.??
You have air in the cooling system. Don't over heat this engine you will cause major engine damage. These cars need to have the air bled out after any work on the cooling system. There is a bleeder on top of the thermostat housing that you can crack open with it running. You will see air bubbles come out. It takes quite a while to get all the air out.
If it heats up while going down the road most likely not the fan.
We have opened both bleeders until it running green then after it sets over night have to to it all again..
How do u check to see if the fan is working properly??
Should I only bleed the one on the housing and not by the water pump??
Would a bad serpentine belt cause this problem??
Serpentine belts are either working or not working they usually don't slip. Doubtful the belt is causing your problem if it is in one piece. You can bleed system anywhere you have a bleeder the one on the thermostat housing is the most effective. It does take time to bleed the system don't rush it. A good trick is to put a tube on the bleeder and stick the other end into water. You will see the bubbles come out to let you know there is still air in the system.
If you bleed the air out and it comes back, it has to be entering the cooling system from somewhere. Pontiac GP, 10 years old, V6 - if it has 60-100,000 miles it could be a lower intake manifold leak unless you changed it already.
And also when I turn the car off I hear bubbles in the reserve like coolent going back in.. why would that be?
No leaking by the manifold..
The bubbling you hear is most likely the coolant boiling because it is so hot! The cooling fans should switch on when the coolant reaches about 220° F or when the temperature gauge is at around the 3/4 mark. From your symptoms I have to say the coolant is very low due to air being in the system. HTH. -Jim
Check orientation of thermostat, check for bubbles coming into reservoir indicating head/head gasket. .....
Bubbles going into the reservoir means a bad head gasket.
Another thing to look at is check the lower radiator hose that connects the radiator to the water pump inlet.......if the hose is bad ----it will collapse at high engine speeds (due to pump suction pressure) thus no water would flow to the engine, To check the hose: warm the car up to operating temperature, open the hood, Rev up the engine to a high speed (4000 rpm), watch the hose if it collapses. Just trying to elimnate things before you go and tear into the motor.
3800 engines rarely if EVER have a headgasket failure unless severely overheated. Have you replaced your intake manifold gaskets, they are known for leaking coolant into the oil. Then you end up with spun rod bearings....
You definatley sound like you have a cracked head gasket..they can check at a rad shop by putting in some dye if it turns a certain color they know right away
I have the same car 99 grandam I have replaced water pump,thermostat,and radiator and every hose now my radiator fans are not working,please help.
im taking thermastat out this summer on my 97 gtp untill i fix fan problems
I had same issue; replaced cracked plastic cooling elbows with aluminum elbows and bleed off air in system. 100%. 118K miles 2002 grand prix GTP. Check for water in oil = brown foam oil. use a blue liq. compression checker, yellow color change = cracked head/gasket. check levels of coolant, low = leak. white exhaust smoke = cracked head/gasket. Smell for coolant odor = leak. look for coolant under car = leak. Last $150 to flush system out, possible clogged radiator.
i have the same problem on my 96 gp. heat worked til i got thermostat changed.same issue, temp gauge rises unless doing 55+. no leaks. what s the deal?
I have 2004 nissan altima 2.5 put in new water pump both thermostats and car still heats when driving and cold when you stop
Did you try coolant temp sensor?
What about wiring linked to coolant temp sensor? Are you sure your gauges are working properly?
As long as coolant isn't pouring out of your engine....it's most likely one of those. You know, if you have bad radiator hose, in cold weather they will get deflated....look like they have been sucked in. Take the radiator cap off and start your engine. Once your engine is warm, you should start to see coolant spilling out of the radiator neck. If you see coolant, you have good flow. If no coolant, put enough coolant in to a point just below the top of radiator neck.
Margie66 did you ever figure out the problem?
I had the same problem (2002 3.1 Grand Prix ) it ended up being my radiator cap was faulty causing small leaks when at highway speeds and also air to enter the system. After I replaced the cap and bled it never had the issue again.
I had that problem unhooked heater core softly blew air threw, rust came out, just bought car, had one long cold middle of the night drive home 20 days ago. Now, more heat than ever!!!!!!!!!!!!!!
Hello can someone please help me I own a 2004 Grand Prix GT and my temp. Gauge started going way to high and I stop getting heat nothing but cold air and I changed the thermostat still have problem I checked my hose to firewall there hot and radiator hoses both hot and fans turn on.. Now I'm so lost and now I'm scared to drive so of anyone is out there please help me
Did you bleed any air out of the system? If so and you have the 3800 V6 check for a failed intake manifold gasket. These engines are notorious for that. HTH. -Jim
How do I do that and no I did not bleed system I can't find where to?
There should be a bleeder screw on top of the thermostat housing. With the engine cold, open it and remove the radiator cap. Fill the radiator to the very top. Watch the bleeder screw and let it sit for 2 minutes. The coolant will go down. Fill the radiator again. Watch the bleeder screw and wait another 2 minutes. Repeat this until you have a steady stream of coolant coming from the bleeder screw. Now close the bleeder screw and fill the radiator to the top again. Now start the engine and put the heater on. If the coolant drops off fill the radiator one last time and put the radiator cap back on. Now fill the plastic recovery tank to the full hot line. To check for a leaking intake manifold, remove the plastic top engine cover and look all around the top of the engine for signs of coolant. If none is present pull the oil dipstick and look for white milky "goop" on the dipstick. Also check the underside of the oil filler cap for the same. If it's there, most likely the intake gaskets have failed. These engines very rarely blow head gaskets. But those intake gaskets are a given. Usually between 90,000 and 120,000 miles is when they go. If your mileage is in the 130s or higher it's pretty safe to assume that the gaskets have been done already. HTH. -Jim
When I take the cap where my oil gets refilled there's the milky goop like sizzling what's that mean ??
That's either going to be that intake manifold gasket or possibly a clogged PCV valve. The PCV valve sits under the MAP sensor on the top passenger's side of the engine. Look for the black plastic gizmo that's shown in the picture (courtesy of rockauto.com). Before you try to remove the MAP sensor buy a new PCV valve kit. That plastic piece almost always breaks when you try to remove the MAP sensor. You'll then twist off the plastic gizmo and pull the PCV valve (shiny metal thing in the picture) straight up and out of the intake manifold. Shake it. If it doesn't rattle it's clogged. This can give you that milky "goop" on the underside of the oil filler cap. How's the oil dipstick look? How many miles are on your car? HTH. - Jim
Well all, here it goes I have a 1997 Grand Prix with the 3800 series 2. I have a list of things that are wrong with it that may need mentioned because I'm starting to see a trend on several forums. First off my blower motor only works on 5. I've change the resistor and checked all HVAC fuses.I think this is due to a faulty ignition switch. This now leads me to my next problem which is no heat but I also didn't have cold Ac this summer and I thought that might've been vacuum lines since the sytem was charged. This heat issue started about five days ago and I found out when I tried to replace the thermostat that it had orange coolant in it which I believe is dex cool and can create a sludge. There's no water in the oil or noticible oil leak into the coolant and with 115,000 miles I don't really want to believe that it could be a head gasket or manifold gasket so I'm going to start with a radiator flush and go from there. To add to this my temperature gauge fluctuates From 120 to 210 while driving but never overheats even with the new thermostat I've bled the system and there's no air bubbles. An Additional problem, for people that Grand Prix's, that I've ran into is water leaking in the passenger-side floorboard, which I believe is the cabin filter water deflector. I will check that out tomorrow. Any other advice would be appreciated.
At 115,000 miles you're due to have those intake gaskets fail. The no heat and temperature gauge fluctuation points to air in the cooling system. You don't have a cabin air filter. There is a provision for one but the Grand Prix didn't get one from the factory. Are you losing coolant? If so, I'd suspect that the water on the floor is coolant coming from a leaking heater core. As for the blower, it could be the fan switch on the dash. There are also 2 blower motor fuses. One for speeds 1 thru 4 and a separate fuse for speed 5 only. HTH. - Jim
Ill have to take a look, the water in the floor doest smell or look like coolant, and what i have read, people have had problems where that provision is. Some how the gasket slips away from cowling and alows water to flow down the hole or filter. Ill have to investigate and find out. Im not looseing any coolant. Plus, i cant get the air out of my system, and before i changed the thermostat it was doing the fluctuation as well. I know i need to elevate the front use the bleeder and a funnel in the radiator, but are there any other ways? And i picked up a salvage fan switch a month ago so ill try that before the ignition. Thanks
I have a question.I have a 97 Grand Prix Pontiac 3.8 and I replaced my water pump, radiator, and thermostat in my car, well after 3days of driving it my radiator hose busted. Got that repaired yesterday, now I'm driving the car and my low coolant light keeps coming on ck the fluid level and the jug and radiator is taking the fluid like it has never had any it! What could be my problem? I'm getting very frustrated.
Car is getting very hot under the hood but it's not running hot!
Pull the oil dipstick. Does it have white milky "goop" on it? If so, the upper and lower intake manifold gaskets need replacing. The 3.8s are notorious for this. Usually between 90,000 and 120,000 miles is when they fail. It's not going to be a head gasket. The 3.8s rarely, if ever, blow a head gasket. The coolant has to be going somewhere. Check your heater hoses and the plastic elbows at the belt tensioner. If the elbows are leaking replace them with the better metal ones that are now available. If you're very low on coolant fill the radiator directly to the tip top. But wait until the engine is cold to do so! HTH. -Jim
Im having to same an i just fex my car just off reading yalls feed back thank you guys
Ok so I have a 2002 pontiac grand prix se 3.1. I'm kinda lost at what to do since I'm not a car guy, I do have mechanical abilities as I have fixed a couple things already on vehicles. But I was wondering, I'm having an overheating problem due to my radiator being sucked dry, air getting in my coolant system which I've bled twice. It'll run fine for a couple days after I bleed it, then start to overheat, I seem to be loosing coolant below the belts and near the back of the engine when the car starts to overheat. Sometimes I also don't have heat. It's not like I'm loosing fluid all the time because most of the time I can't see any apparent leak. I've ran the car with the radiator cap off and it seems to be circulating well. I know my information is all over the place but like I said I'm not a mechanic!!! Please respond asap with any information
Chrisjay21, these engines are notorious for blowing head gaskets. To me that's what it sounds like. Especially if you're between about 90,000 to about 120,000 miles. Pressure test the cooling system and see exactly where you're losing the coolant. HTH. -Jim
I have a 2007 gp the temp gauge gets well over half but no check engine light, I opened the oil cap and it was steaming I was thinking maybe heater fittings are bad but there's no check engine light?
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