My 2000 4x4 has little heat on cold days and the engine temp runs between 160F and 170F. This seems a little cool to me. Could it be that the themostat has failed and is in safe mode stuck partly open not allowing it to heat up enough to provide enough heat? I did have the coolant system flushed recently which improved the heat somewhat. The vehicle has 102,000 mileson it and am wondering if the original water pump could be failing as well and maybe has low flow??

 

You'd see higher temps if your wp was failing. It is possible that the stat has failed open... Even at a coolant temp of 160*F, it should get warm inside.

When was the last time you flushed the coolant system. In a 2000, if it hasn't been done, you are at the end of the life of your extended life antifreeze (5yr/100,000mi). I will be flushing the system on my '00 Bravada this week. Well having the dealership do it because I've got a coupon to have it done for $35. It's not worth my time to do it myself! It is possible that your heater core has been partially clogged, but during a flush, that should get some special attention if you state that you have little to no heat coming out inside.

Good Luck!

 

I just had the coolant flushed last week. First time I have had it done. It still had the 100,000 mile newer type coolant in it. I am getting more heat since i did that so I'm thinking maybe the heater core is clogged. 160F still seem slow to me. I think 195F thermostats are suggested this model. I think they do sell a 170F though.

 

What I was saying is that even at a coolant temp of 160*F, you are still going to get decent (not really hot) heat inside if the heater core is working properly. During a proper flush, the heater core hoses should be removed and the heater core should be flushed both ways to clear any debris out of the core.

I do agree that 160*F temps is way too low for a stock stat. It is low enough that on newer vehicles, the PCM would throw a code and it wouldn't enter closed loop operation being that low (trigger is at 165-170*F for closed loop operation). 160*F seems like a reasonable temp for the radiator to support if the stat is stuck open.

 

You might have a 160 degree theremostate, you probably do.

 

unless he changed out the stat to a 160 he would have a stock 195 in there... 160 stat is too low for our blazers

 

The 175*F stats may be too cold. As I stated earlier, the newer ('96 and later) require a specific time to full warm up and it will throw a code if it isn't hit in so many cycles. I can't remember how many that is, but given enough time, you'll get an 'insufficient warm up time' code.

 

here is my problem, i have a 96 jimmy and the temp goes all the way upto where it should be 210, and then it drops down to 155 and stays their

 

Nick, I'd guess either a bad themostat or bad ECT (engine cooolant temperature) sensor. First, check the electrical connection to the ECT which is on the top of the engine right in front of where the water outlet tube bolts on.
BTW, holy old thread resurrection!

 

haha yeh. i just had the thermostat replaced last fall thinking that would solve it.. and i checked out that engine coolant sensor. seems like everything is all good there.. the engine temp guage in the jimmy goes up to the correct temp like everything is where is should be anf then drops randomly but it seems to be getting some reading off it.. idk. im a highschool student. u think a sensor would be a big cost or wat budd?