Ask Me Help Desk - No heat/erratic temp gauge

I own a '97 Chevy Monte Carlo. I'll try to make this as brief as I can.

About two weeks ago I noticed that my warning light for high temp was lit. I was shocked because I had only been in the car 10 minutes. But then it started to go down. Then it was kind of floating up and down. Also, I noticed I had no heat.

I took it to a chevy dealer near where I work so I could have the work done and I could walk to my job. I think I made a big mistake. First of all, I don't know much about cars but I thought maybe it was my thermostat. I mentioned that when I brought it in, and they asked if I was overheating. I told them what happened (no heat, erratic temperature readings) and they took it in. Later in the day they said it was fixed. The causes:

1) I had an erratic gauge because there was a broken wire going to my thermostat. They fixed it.

2) My heat issue was caused by having little to no coolant left. They topped it off and did some kind of 'pressure test' for leaks.

Total cost: 180 dollars... 80% for LABOR.

Well, they DIDN'T fix it. Still an arratic temp gauge, still very little heat. Oh, and NOW I had a 'low coolant' light coming on. I called them and explained, and they said to bring it back in. Probably mistake #2.

Even though they said they would 'adjust for the labor costs' because I DID NOT have the problems fixed the FIRST time I went in for service, my bill was still 450 dollars. This time, they said:

1) I had a leak in my water pump. That was likely the cause of my heat AND temp problem. They relaced the water pump.

2) Unrelated to my other issues, the mechanic (and I use that term loosely) found a leaky gasket that was dropping transmission fluid. This I had known about for awhile, and told them to fix that, too. So that's where the additional $$$$ came from. But still, the water pump cost 150 bucks (probably refurbished?) plus labor. AND FOR WHAT?

I STILL have a floating temp gauge, although it's not quite as bad as it was. It doesn't peak in the red (so far), but it does go up and down to about the 1/2 way point, sometimes a bit further... but not all the time. As for the heat, it's better... but very sporadically warm. It goes up and down, too. It'll stay warm (and not even really hot) for 30-45 seconds, and then I can feel it get cold again. After a minute or so it gets warm again. It does this off and on vs. before when it was blowing mostly cold air.

Can ANYBODY give me advise on this? What can the problem be? Should I cut my losses at the dealer and go someplace else who KNOWS what they are doing, or does the dealer OWE ME MONEY for jipping me twice? Shouldn't they be inclined to fix my car for NO cost, since I've already given them over 600 dollars with only MINIMAL improvement? Very, very frustrating. Thanks for any help you can offer.

First of all, as a consumer, you do not pay if it was not fixed. If you are fed up with this dealer I would insist on all my money back and be happy with 75%. Call one of the tool trucks and ask for the name of the semi new machine that evacuates the coolant from the radiator system and then fills it back up behind the vacuum, practically insurring there is not air bubbles left in the system. I cannot remember the name, it is all over the net on a professional site I go to. AirLift,? Go to a shop with this machine.

I think you still have air in the system, did they remove the heater hose to bleed the heater core, or backflush it at all.

Quote:

Originally Posted by Duane in Japan

First of all, as a consumer, you do not pay if it was not fixed. If you are fed up with this dealer I would insist on all my money back and be happy with 75%. Call one of the tool trucks and ask for the name of the semi new machine that evacuates the coolant from the radiator system and then fills it back up behind the vacuum, practically insurring there is not air bubbles left in the system. I cannot remember the name, it is all over the net on a professional site I go to. AirLift, ?????? Go to a shop with this machine.

I think you still have air in the system, did they remove the heater hose to bleed the heater core, or backflush it at all.

I AM fed up w/ the dealer... I just don't expect to get much (if any) of my money back. And it's tough to NOT pay for lack of proper services rendered when you aren't allowed to leave the lot w/ your car until you pay. In my case, I had to drive the car for a little while before I knew if it was fixed or not. If I go back there again, I have the feeling they are going to repair something else that doesn't need repairing and the cycle will continue.

I have no clue if they removed the heater hose to bleed the heater core... or backflushed. Maybe I should ask? I didn't notice anything like that on my invoice. Unfortunately I think I made a very expensive mistake going to this dealer because now I hear from co-workers who went there that they had bad service there, too. I should have asked around. I don't know how a huge Chevy dealer could stay in business with the lousy work they do. This problem should be an in and thing (or so it seems) and instead I'm left w/o heat and an erratic temp gauge for over two weeks.

Let me ask you: IF there is really air in the system, is that what's causing my engine to run hot, then cold... so erratically? Or are those readings false due to the air pocket problem? I find it hard to believe that a temp gauge can start to rise as quickly as mine does after driving the thing 5 minutes. Can engines heat that quickly and change temperature as dramatically as mine appears to be changing? I very concerned about running the engine too hot, obviously. So this is a problem I need fixed ASAP. Thanks for your help.

I would like to ask you for an hour of your time to diagnose this thing. Start the car cold, monitor both radiator hoses with your hands, be careful of course. As the temp of the engine raises, eventually the thermostat is going to open, as water flows through the radiator the lower hose will heat up, at some point the radiator fan is going to come on also (if its an electric fan).

Do you see the two heater hoses going into the firewall, do you notice some kind of a shut off valve in one of the hoses, either cable controlled or vacuum controlled, or maybe no valve in sight. Monitor these hoses as well, with no shut off valve or with the valve open (heater set to hot and blower fan on), both hoses should heat up at the same time.

Getting everything to heat up, open the thermostat a couple of times and turn on the fan (I/A) may take some real time, especially when its not hot outside. Let me know what you think.

Quote:

Originally Posted by credit_card_debtor

I own a '97 Chevy Monte Carlo. I'll try to make this as brief as I can.

About two weeks ago I noticed that my warning light for high temp was lit. I was shocked because I had only been in the car 10 minutes. But then it started to go down. Then it was kind of floating up and down. Also, I noticed I had no heat.

I took it to a chevy dealer near where I work so I could have the work done and I could walk to my job. I think I made a big mistake. First of all, I don't know much about cars but I thought maybe it was my thermostat. I mentioned that when I brought it in, and they asked if I was overheating. I told them what happened (no heat, erratic temperature readings) and they took it in. Later in the day they said it was fixed. The causes:

1) I had an erratic gauge because there was a broken wire going to my thermostat. They fixed it.

2) My heat issue was caused by having little to no coolant left. They topped it off and did some kind of 'pressure test' for leaks.

Total cost: 180 dollars.....80% for LABOR.

Well, they DIDN'T fix it. Still an arratic temp gauge, still very little heat. Oh, and NOW I had a 'low coolant' light coming on. I called them and explained, and they said to bring it back in. Probably mistake #2.

Even though they said they would 'adjust for the labor costs' due to the fact that I DID NOT have the problems fixed the FIRST time I went in for service, my bill was still 450 dollars. This time, they said:

1) I had a leak in my water pump. That was likely the cause of my heat AND temp problem. They relaced the water pump.

2) Unrelated to my other issues, the mechanic (and I use that term loosely) found a leaky gasket that was dropping transmission fluid. This I had known about for awhile, and told them to go ahead and fix that, too. So that's where the additional $$$$ came from. But still, the water pump cost 150 bucks (probably refurbished?) plus labor. AND FOR WHAT?

I STILL have a floating temp gauge, although it's not quite as bad as it was. It doesn't peak in the red (so far), but it does go up and down to about the 1/2 way point, sometimes a bit futher.....but not all the time. As for the heat, it's better.....but very sporadically warm. It goes up and down, too. It'll stay warm (and not even really hot) for 30-45 seconds, and then I can feel it get cold again. After a minute or so it gets warm again. It does this off and on vs. before when it was blowing mostly cold air.

Can ANYBODY give me advise on this? What can the problem be? Should I cut my losses at the dealer and go someplace else who KNOWS what they are doing, or does the dealer OWE ME MONEY for jipping me twice? Shouldn't they be inclined to fix my car for NO cost, since I've already given them over 600 dollars with only MINIMAL improvement? Very, very frustrating. Thanks for any help you can offer.

I have the same car and the same problem but i haven't taken it to a shop yet i was trying to figure out what was wrong with it... i know how you feel

I had a 2001 Chevy Impala, very similar car and probably the same 3.6 liter. My problem was an erratic temperature gauge that would also shut off. By this I mean the gauge would bounce for a while, then drop below cool and stop working. This caused my radiator fan to come on and not turn off. I went to the dealer who changed the computer under the dash... that did nothing. They changed coolant, nothing. Temperature sensor, nothing.

After hundreds of dollars, I finally changed the thermostat by myself - this fixed the problem. I later found a reference on a web site by a shade tree mechanic who said the problem resulted from a design flaw in the engine. The thermostat is located at the engine after where the hot fluid exits the engine. When the thermostat failed, the computer became "confused" and shut off the gauge.

Not sure if that explanation made sense, but it fixed my problem!

The problem more that likely is the gauge. GM's electronics are a joke. They have the life cycle of a couple of years at the best. My fuel gauge shows full all the time. I was told I would have to install a sender unit (dropping the tank) at the cost of about $450. I passed on that and set the trip odeometer to zero whenever I fill up. That has worked fine for the most part (I have run out of gas about three times). Now (at 137,000 and a new engine at 122,000 miles) my tempeture gauge in bouncing around. I like having my Van but GM doesn't seem to want any longevity in their products. I going to try Ford or maybe even Chrysler the next time.

I have a 2003 Ford F150 5.4 triton and it is doing the same thing. We have changed the thermostat twice and still not fixed the issue. I actually had a mechanic tell me that he has no idea what is wrong with it and I should take it to a Ford Dealer.

I brought my car "02" Monte Carlo, into a garage about 2 months ago. The reasoning was because the check engine light would not turn off. They said they needed to clean out the upper intake that it was clogged with residue. $500 later, I bring the car home and notice antifreeze leaking. I had to replace the radiator, replace the water pump, a sensor, and the thermostat. The gauge still fluctuates and only overheats at times. I don't want to take it back to the original mechanic as they seem a little shady. Every time I go in something else is wrong when I leave. The car is still at the garage that replaced the thermostat and sensor. Is it possible the computer was cleared and it could cause other issues. The engine was swapped two years ago, an Impala 3.4. It ran fine until the check engine light was cleared out.

lawssusan72, find out what codes were thrown. The codes should send you in the right direction; otherwise, the ECM is bad.