'97 Grand Prix GT Help Heater problem

I have a 1997 Pontiac Grand Prix GT with 90k. About a week ago my car heater started acting up. The heat comes out warm instead of hot and the heater only works on the highest level (5). What's going on with the heater and is it an easy fix or will I have to take it somewhere, how much will parts and labor cost? By the way the heated seat seems to work fine and the rear window is fine. Thanks for the help.

I read that it could be the HVAC fuse is blown because that controls levels 1-4, could that be correct? Where is the fuse box located on the '97 Pontiac Grand Prix?

Two fuses that could affect it are the HVAC CTRL and HVAC HI locatd in the fuse box by the glovebox. Since the blower works in position 5 the HVAC HI fuse is good.

If the fuses check good then most likely you have a bad blower motor resistor (BMR) or blower motor control module. Manual HVAC uses the BMR and auto climate control (ACC) uses the module.

As far as for low heat check the thermostat.

Thanks,

I know very little about cars, were can I check the thermostat? I will check those two fuses you mentioned tomorrow and get back to you, much appreciated.

You're welcome. The link below located at our Tips & Maintenance subforum will show the location of the thermostat and how to replace it. Sounds like yours is stuck partially open or not regulating at the stock 195 degree mark. Good luck.

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=652667)

Also the warm air is coming only out of the middle consoles the far left end and right end consoles has nothing.

I'd start with checking the HVAC CNTRL fuse and also make sure there is 12 volts at the fuse socket even though the fuse may look good. The vents are controlled by a combination of electrical signals from the climate control unit and engine vacuum. There are various actuators used to control the HVAC system vents and temperature. The engine vacuum source is the Y fitting at the rear of the upper intake manifold and routes along the firewall, then by the battery and into the main wiring harness that runs into the firewall.

I checked both fuses and their fine, I never checked the HVAC CNTRL fuse for 12 Volts. When the settings are on 1-4 it doesn't even sound like anything "turned over".

I would say you may have more than more problem with your HVAC system. However, the missing blower speeds 1-4 is typically a bad blower motor resistor providing that you have a manual not digital - ACC.

could it possibly be low on coolant?

could it possibly be low on coolant?

I could see the low coolant causing heat loss but can't see it affecting the blower. BTW you can test the thermostat by boiling it in a pot of water, this will tell you if it is opening, then take it out if it opens ( I used a fork..lol) then as it cools you should see it closing. I even went a step further, you can buy a thermometer to tell you exactly what temperature it opened at. I used one which is used to cook some kind of hard candy or something, dunno it was a gift as I was asking everyone if they had the type you stick in a turkey..lol, well this one worked like a charm and showed my thermo opening between 88 and 93 degrees Celcius. Its supposed to open at 91, not bad in my opinion, cool little gadget :)

One symptom that I've seen on SII 3800 engine when the coolant is actually low in the radiator and reservoir is you will get that classic gargling sound in the cabin area of the HVAC where the heater core is located. Like when you gargle with mouthwash. Coolant is constantly flowing through the heater core whether you have heat on or not.

"One symptom that I've seen on SII 3800 engine when the coolant is actually low in the radiator and reservoir is you will get that classic gargling sound in the cabin area of the HVAC where the heater core is located. Like when you gargle with mouthwash. Coolant is constantly flowing through the heater core whether you have heat on or not."


bnaylor-
I have that same sound although I would say it is more of a "swooshing sound" like fluid is moving back and forth.

Should I check the coolant? Or what should I do? It's been making this noise for about 1 year now.

bnaylor-
I have that same sound although I would say it is more of a "swooshing sound" like fluid is moving back and forth.

Should I check the coolant? Or what should I do? It's been making this noise for about 1 year now.

As for your low heat problem absolutely. Be sure to check the level in the radiator first and then the reservoir. As to the blower speed control problem that sounds like another issue.

I Agree I think its the blower motor resistor because levels 1-4 on the blower are "dead". If I took this to a GM dealer how much would a new blower motor resistor cost to replace with labor?

I checked the coolant and it was bone dry. I put coolant in it and the heat was coming out HOT. I still need to work on the blower because levels 1-4 don't work.

Thanks for the help.

I Agree I think its the blower motor resistor because levels 1-4 on the blower are "dead". If I took this to a GM dealer how much would a new blower motor resistor cost to replace with labor?

Are you DIY capable? If you are you can save on the labor costs which could be up to two hours labor charge at the dealer's hourly labor rate for electrical. We can post a procedure with pics. The GM dealer will charge top dollar for the resistor around $50 when you can get one cheaper. AZ has the Wells brand for around $25-$30.

Are you DIY capable? If you are you can save on the labor costs which could be up to two hours labor charge at the dealer's hourly labor rate for electrical. We can post a procedure with pics. The GM dealer will charge top dollar for the resistor around $50 when you can get one cheaper. AZ has the Wells brand for around $25-$30.



Post the part # for the blower motor resistor and I will buy it at autozone. I will have someone I know do it on the side, if they are mechanic and know what they are doing how long should it take them?

Wells PN: DR783, $19.99.

Tech procedure below. About one hour. Good luck.

Click here (http://www.clubgp.com/cgi-asp/mods.asp?modid=150)

I checked my coolant today and I have a coolant leak. The tank was almost empty from filling it just 24 hours ago.

I checked my coolant today and I have a coolant leak. The tank was almost empty from filling it just 24 hours ago.

That doesn't sound good. Do you see any external leaking? You are either leaking the coolant out externally or internally which will require a closer inspection. Look for coolant on the ground and any leaks from cooling system components and the engine. If no external leaking is found then coolant is being consumed internally. In that scenario most likely upper intake manifold or lower intake manifold gasket problems. Since you have a '97 model a UIM problem may be likely due to the EGR stovepipe problem on '95-'98 GM cars with the SII 3800.

Check it out as soon as possible because if the coolant loss is internal through the intake system it may cause the engine to hydro lock and blow the engine.

I took my car to my mechanic and he fixed the blower, he put it a blower motor resistor and it's now working on all levels. He told me I have a coolant leak in the intake gasket and the valve cover gaskets, he told me if the coolant gets into the oil I will have serious problems, is he correct?

Also how long should this job take, he told me 6-7 hours to remove the gaskets to fix the leak and about $300 for labor with basically no parts, is this a good deal?

Absolutely. You may get bearing failure...crankshaft, connecting rod, camshaft, valvetrain, etc. The bad part is coolant consumed internally via the UIM or LIM is bad enough. For a pro that is about right for both UIM and LIM. DIY may take you all day or two but you will save on labor costs. Stealership and Shops may charge upwards to $1K with parts for both UIM and LIM. The $300 labor doesn't sound bad as long as the work is done right and guaranteed. It will be a couple hundred for parts to include a new UIM plenum and all gaskets/hardware.

We have another thread going where one of our members is doing the UIM/LIM job DIY. Check it out when you get a chance.

I've had this same coolant leak now for about 1 year that I know of because when I use to get my oil changed they would tell me. Wouldn't have I had problems with the above mentioned if it's been a year, can I just go without it?, what's the odds of something happening?

What is the UIM and LIM?

Where exactly is the coolant leak?

UIM = Upper Intake Manifold
LIM = Lower Intake Manifold

I don't know exactly where it is. Where is the leak usually worse to have in the UIM or LIM?

I don't know exactly where it is. Where is the leak usually worse to have in the UIM or LIM?

The original issue for '95-'98 GM cars with the SII 3800 was the UIM and an EGR stovepipe problem causing a meltdown, damaged coolant passages and loss of coolant. However, the LIM gaskets could give you the same problem which is an unexplained loss of coolant. In your case the UIM needs to be removed to see why you have the coolant loss since it does not appear to be an external leak. Then an assessment can be made. No guarantee you will be able to get by with the problem. The issue should be looked at as soon as you can.

I've had this same coolant leak now for about 1 year that I know of because when I use to get my oil changed they would tell me. Wouldn't have I had problems with the above mentioned if it's been a year, can I just go without it?, what's the odds of something happening?


If the coolant has been leaking into the oil for that long...
:shakehead that's not good :grinno:
You bearings will get pretty scratched up from this.

That is a good price for labor too , like Bob said if its guaranteed.

Also check your resivior for cracks. I have seen may leak out the bottom/sides, possibley from freezing when not enough coolant was in there.
Just my :2cents: