Okay so the other day my car started running really hot and the heat quit working at the same time. I mean the temp gauge tops out within 2 miles of driving.

Now I just jumped to the assumption that it was the water pump from past experience with a Jeep I had once. I just figured I would ask real quick, what small stuff could I possibly troubleshoot here before jumping to a job as big as the water pump is going to be?

I am pretty new to the DIY mechanic work so I really apreciate the help and the potential amount of time and money that may be saved ha ha!!

Thanks!

 

thermostat, temp switch, headgasket, warped head, radiator hoses, water pump, etc....

 

Thanks a ton, would you suggest checking in the order you listed them? I may be very happy I asked this before ordering the water pump. I didn't even consider the thermostat ha ha.

 

test the radiator, any time ur heater stops working it means that there isnt any fluid going through the heater core. identify where the problem is 1st b4 u start tearing the head off

 

Sorry man, I gotta ask a dumb question. how do I test my radiator?

 

1. With the car cooled down, remove the radiator cap and check fluid level. (it should be full).
2. Then check radiator fan by warming up car, and the coolant fan should turn on as you get to normal operating temp.

- if it does turn on, and you are not leaking coolant, it is most likely thermostat or headgasket.

- if it does not turn on, the fan is either not receiving power or the fan motor is done. Try unplugging the fan and running power/ground to it and see if it turns on. Then test as the car heats up to normal operating temp, 12v power should turn on to power the cooling fan.

 

if its overheating while driving odds are its not your fan. check if both your radiator hoses are hot. if ones cold then its the thermostat. check coolant level, if your heat sucks then chances are NO coolant is passing thru your heater core due to the thermo not operating properly

 

Thank you hachet! The simple suggestions are always my favorite. I'm going to check that tomorrow when I get home. If it's the thermo I'm going to be extremely relieved, so will my wallet. I'm going to run through the radiator check too, step by step seems pretty simple and it'll be good to make sure all that stuff is in order.

Thanks a ton and I will update with the results.

 

no such question as a dumb question, anytime u learn something its a +

 

You can get a pressure tester for the cooling system to help find any leaks.
If you have an Advance autoparts store near you they usually have one in their loner tools.

 

Thermostats close when cold and allow the coolant in the engine to warm up faster when you first start the car. Then as temp increases, it opens up and allows the warm coolant in the engine to mix with the cooled coolant in the radiator.

Usually when the thermostat fails, it fails in the open position. This causes the coolant to take longer to warm up. Once all the coolant is warm, the coolant will pass through the radiator too quickly to be cooled down and you may experience overheating.

 

Awesome, this has been a very informative thread. I'm going to go look into it tomorrow.

 

heater hose?

 

What about the heater hose? I don't know what you mean.

So here's my update:

Today I installed an OEM thermostat from the dealership, flushed the coolant, refilled it and got it circulating. It seems like it's moving or has pressure because it went down, and once it was full, it looked like it was almost pulsating up and down a small amount. Again, I'm just guessing that means it's getting movement!

At an idle, the temp guage sat just fine at about 1/3 of the way up like normal, but then within a half mile of driving began shooting up again.

It was a little different this time though, the heat inside the car worked after it first got hot, then at a stop light the temp gauge dropped slowly, then straight back up once moving.

Then it would just rise and fall very quickly without anything changingwhile driving back home.

So i went just one block further to see if it would get consistent at all, and had my lovely assistant make this video of the gauge so you can see what I mean.

Does anyone else suspect it may just be a grounding issue with the actual gauge? Is there any other way to determine the engines actual temp and whether it is legitimately overheating?

Thanks a ton for everyones help. I have pics of everything I've done and will make a quick how to thread once everything is figured out.


http://www.youtube.com/watch?v=4v6RP8Xb4KM

http://www.youtube.com/watch?v=g2yc5Ah1zqI

 

Any of you guys have an idea where I should look next? I'm 100% willing to learn how to do whatever it takes, I'm just lost as to what I should suspect next.

 

bump

 

Well, the needle is moving too rapidly to be showing an accurate reading. It may be an electrical issue with the temp sending sensor, the wiring or the gauge.

You actually have two temp sensors. One is for the ECU, but the one we are interested in is a single wire sensor that sends signal directly to the gauge. It works by conducting a certain resistance to ground, and as it warms up, the resistance lowers.

To test Gauge and Temp Sending Unit

 

Alright, so I thought my troubles were over. Thanks for sticking with me on this awful adventure, I replaced the thermostat and coolant about two weeks ago. It ran fine until a few days ago when it began heating up again. I mean same thing, pegs up to the H within a block of driving. I mean seriously, its like the gas pedal controls the temp guage its so fast. Now before I assume its a head gasket, can someone who has been thriugh this before list all the less expensive things I can test before this? I still have no heat blowing through the climate control. It goes down a tiny bit if im idling but not enough. The fans are working, im losing coolant, oil is clear, coolant smells and looks fine. Im lost!!! Thanks a ton!!!

 

Anyone, there are videos above of what the temp guage is doing.

 

I watched the videos, and i suspect the temp gauge/sending unit are not working properly. The engine would not truly increase and decrease in temp so rapidly, so it seems like the gauge cannot be trusted. Either way it is critical to eliminate them as a possibility and thats why i suggested you check the gauge/sending unit.

 

It is over heating though, smoke came pouring through my dash vents today. I still agree with you, its probably not accurate, but it is overheating.