Why is coolant disapearing?

135

Asked by Oct 05, 2012 at 12:46 PM about the 2002 Pontiac Grand Prix

Question type: General

Coolant light came on, filled to the proper level with Dex-cool, checked rad and looked for leaks but none under car. Looked near fan belts, the "tray" under the engine has a little coolant there but not as much as I have put in. I've owned this car for a month now and if it was'nt for the excellent body and int and all operational and fun to drive I would sell it!  

39 Answers

2,235

check your water pump

15 of 15 people found this helpful.
135

I was afraid someone would say that. Thanks John. Will the computer give me a warning or something?

2 of 2 people found this helpful.
200

Check your oil if it is milky or foamy you have a blown head gasket, it could also be escaping through the exhaust if the head gasket is blown, if you have a white smoke exhaust there it is.

3 of 3 people found this helpful.
135

The oil is good but the exhaust is a little white?, but not really white or heavy? Thanks.

4 of 4 people found this helpful.
200

Have the system pressure tested it will give you an answer

4 of 4 people found this helpful.
685

Is it a 3800? If so,remove the plastic cover and look for coolant leaks between the upper and lower intake.

4 of 4 people found this helpful.
Best Answer
135

Thanks Riccardo.(Big plastic cover off) I found on the upper, where the plastic covers the (lifters?) a pooling leak on the drivers side and a slower leak on the pass. side. Would that be coolant or oil? Still no leak under the car.Thanks.

1 of 1 people found this helpful.
2,235

it would be a coolant leek would recomend a change of gaskets

5 of 5 people found this helpful.
135

Thanks John. Is that a big procedure on this car? It seems easy to get at?

3 of 3 people found this helpful.
33,705

DO NOT forget to change the plastic elbows that go to the belt tensioner. They are like $5 and known for having leak issues after being removed. Go to autozone.com and type 47065 into the search. Only one result will come up under parts for a heater hose fitting.

4 of 4 people found this helpful.
2,235

fairly easy if you know a bit about cars but would if you feel it is a little beyond capabilities refer to a haynes manual it will explain it in detail

1 of 1 people found this helpful.
135

Thanks John and John. I do some things but with electr and engine I leave that to guys who know what there doing but as you can see I like to be involved with the process.

685

Hey Pete you won't see any coolant under the car because it will pool where you saw it and sometimes burn off.I had the identicle problem with my GP.The bonus is that the gaskets are the upgraded ones as opposed to the original.Good luck.

3 of 3 people found this helpful.
135

Thanks Riccardo. I guess that solves that, at least it's up on top to work on. I bought this car cheap because of the excellent condition(paint/interior etc). Mechanically it needs stuff but you get what you pay for.

135

Thanks Riccardo. I had one more thing to ask. You said you had the same problem? I was looking for all things for a blown head gasket but I didn't have all them just coolant lose. Is that still a blown head? Thanks.

1 of 1 people found this helpful.
33,705

GM has intake leak issues from 99ish to 03ish on pretty much all v6 engines. The 3.1, 3.4, 3.8, and 4.3 are known for the lower intake going bad due to the dexcool being acid based destroying the crappy gaskets and the 3.8 also has issues with the elbow going to the tensioner. They aren't known to have head gasket issues. Not saying it isn't the head gasket, I'm just saying the intake is very well known for the issue. Google it

5 of 5 people found this helpful.
33,705

As Ricardo said it pools there and evaporates. It only leaks when the engine gets up to temp and pressurises the cooling system and the coolant evaporates at the same rate it leaks.

2 of 2 people found this helpful.
135

Thanks John. Yes. I don't see the other problems as with head gasket. Like foamy oil, white smoke etc. just the drop in coolant and even that has slowed down. No loss of power. Thanks for the info.

1 of 1 people found this helpful.
80

I have a 2002 pont grand prix se..same problem..replaced water pump. ..still leaks from somewhere see slight puddles under car at times..sometime temp Guage goes up but once I get going it drops and the add coolant light comes on... Can't seem to find leak...

5 of 5 people found this helpful.
33,705

Trucker do you have the 3800?

1 of 1 people found this helpful.
80

3100...I fill radiator every few days..it's getting tiring..car has plenty of power...no issues of blown gasket...find leaks every once and awhile under car...I'm stummped...friend is a some what mechanic and he can't find it...is there a dye I could use to locate leak

3 of 3 people found this helpful.
33,705

Yes there is a dye. It would be your best bet.

80

Where do I put it?? In radiator..and does advanced auto sell it and do you have a ball park on pricr...any special light needed to see it...

33,705

I wanna say around $10 not sure, comes with the uv light and glasses. Instructions on where to put it, I would bet radiator would be best.

80

Lol..OK thanks man...I'll try that today and check it during the weekend after I've driven it awhile. ..

140

I have a 2004 pontiac grand am 3.4 6cyl. We got the water pump replaced a few weeks ago and it is leaking again due to my husband not mixing dex cool and water. Do we need to replace the pump again?

14 of 14 people found this helpful.
60

so I got a 3.1 in my 96 Corsica almost sure its intake manifold gasket but if that is the case would white smoke be coming out of my exaust cause it is some thick white nasty smelling cloud

6 of 6 people found this helpful.
40

Thank for all your help... I have a 3.8 GP... had the water pump and thermostat changed about 2 months ago... been using lots of antifreeze and can't find the leak... I'm not sure if it's the water pump, the intake or just gaskets... I'll have them all looked at tomorrow morning...

4 of 4 people found this helpful.
180

on my 2006 Pontiac grand prix the anti freeze is leaking out behind the motor on the passenger side. is this a freeze plug or is there a radiator hose back there or water pump?

18 of 18 people found this helpful.
60

It took me 16 hours but I overhauled the whole cooling system change the water pump flush the radiator change the thermostat did all that come to find out it was my elbows they are underneath your alternator they run into your heater core they needed to be changed

5 of 5 people found this helpful.
60

I have a 2005 Pontiac Grand Prix

60

Its a 3.8 3800 series 3

1 of 1 people found this helpful.
90

I have a 2004 pontiac grand prix wont stop overheating I've changed the elbows, the thermostat and i cant seem to find the issuse??? Car runs and drives for a while before overheating. Please someone help?

6 of 6 people found this helpful.
20

I

1 of 1 people found this helpful.
20

Hi i have 99 prix 3.8 leaking out the elbow would it make it skip

1 of 1 people found this helpful.
30

I have a 2005 Pontiac Grand AM V6 2.3L 3400 what would cause Antifreeze to come out the exhaust pipe? I've had the car over heat due to cracked radiator which I replaced as well as the reservoir and the thermastat

3 of 3 people found this helpful.
30

Were do u put the head gasket repair sealant on a Pontiac grand Prix 05?

3 of 3 people found this helpful.

My ponitac grand Prix 2000 have all new head gaskets upper n lower but is still shoot water from out the head if u can help me 5612945284 call me in the afternoon please

Upper and lower coolant elbows made of plastic they crack and leak slowly especially if someone added stop leak.replace them cost 5 dollors i recommend aluminium ones cost 11.99 located on passenger side under altinator L shaped from pulley to head easy fix if you you tube it. May pay over 200 in labor rates very common on 3.8 literaat when high mileage fix asap before you chance running hot and blow a rod in engine hope this help god bless car issues are stressfull

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