Skip the auto shop - Our mechanics make house calls

Q: Car is overheating - 1999 Pontiac Grand Am

asked by on

Alright, When I first bought the car the guy i bought it from told me there was 2 problems with the car. A camshaft sensor and a map sensor. I replaced both of them, and the car still didnt crank. I think I may have flooded the engine so i let it sit overnight. Went out the next morning and it crank right up. So I tried driving it down the road and it died every time i tried to give it a little to much gas. So i unplugged the mass airflow sensor now it runs perfectly. I drove for about ten minutes and noticed my temperature gauge started rising. I parked, looked at my reservoir tank and there is a hose that's completely cut off from everything else, I looked it up and it said it was a pressure relief hose, it releases all my coolant and water if there is too much pressure. So its supposed to be there so now im confused. Could this be a water pump problem? I bled the screw that makes water come out so I know there isn't a problem with my thermostat. Is this a water pump?

My car has 183000 miles.
My car has an automatic transmission.

Hi. A bad water pump is a common cause for this car to overheat. This is what I would start with in order to repair the overheating problem. Keep in mind that a clogged radiator or heater core could also cause a overheating condition. This motor in your Pontiac Grand AM is also known for the lower intake leaking causing the car to overheat as well. To avoid any unnecessary repairs, I suggest you have a certified technician from YourMechanic come to your home for a diagnoses of your overheating problem.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car overheated and rattling

Hi. Overheating is a serious issue and can cause significant damage to the engine such as breaking the head gasket or even damaging the cylinders and pistons. You should have a certified technician, such as one from YourMechanic, inspect the...

Q: i replaced my starter and it worked. I went to turn the car off and it kept making a clicking noise.

This is a sign of a faulty starter solenoid or ignition switch. When you turn off the power to the ignition, there is still power running to the starter solenoid causing it to engage the starter. With the ignition switch...

Q: Car won't stay running unless MAF is unplugged.

Short of a vacuum leak, this seems to indicate to a dirty or failing idle air control valve. As you know, the idle air control valve monitors the air intake as it is mixed with fuel prior to being injected...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...