No heat, bad thermostat?

[Grimm]

So on my way home Friday I smelled coolant, and when I checked it getting gas, the coolant was gone in the overflow and the radiator was low. I added some at home, and found the coolant elbow dripping from the water pump end. Took it to a garage Saturday and they replaced it. Now I've noticed lately that the heat doesn't really kick on hot until the temp is set to at least 80 degrees. Well this morning I was not getting any heat. I didn't think to check the coolant before I left the shop this morning, but when I got to work, the coolant was way over the hot line. Could this be because the thermostat is stuck closed (assuming the mechanic didn't fill it to the hot line)? But then I would think the car would overheat. Normally the temp gauge is just a hair shy of 200 degrees, but I noticed this morning it took a good 15 minutes (30 minute drive) just to get to the line before 200. After that it came close to 200, but I also noticed it fluctuate between the two every so often. I didn't think to check if the radiator hose was hot. I'll do that when I get home, and I can also try bleeding at the thermostat as well.

[myfirstbonnie]

They probably did not get the air out of the system. With the system cold, fill the radiator and set the overflow to the correct level. See if it helps and check the fluid level again.

Have you done the LIM and gaskets yet? Any white smoke from exhaust?

[Grimm]

Yes, both have been done several years ago. Hopefully I'm still good there. No smoke. I do remember them saying they topped off the coolant, so they may not have even attempted to see if there was any trapped air. I also saw a post about revving the engine a few times to purge the air from the heater core, so I'll try that as well tonight. I'll also check the coolant level when I leave work to see how high it ends up.

[imidazol97]

So on my way home Friday I smelled coolant, and when I checked it getting gas, the coolant was gone in the overflow and the radiator was low. I added some at home, and found the coolant elbow dripping from the water pump end. Took it to a garage Saturday and they replaced it. Now I've noticed lately that the heat doesn't really kick on hot until the temp is set to at least 80 degrees.

Check coolant in radiator to be sure the coolant is being pulled back in when it cools and shrinks in the engine volume.

Then check thermostat by starting the engine when cool or cold and holding hand on the heater hoses after 3-4 minutes and on the upper radiator hose. The heater hoses should start to warm with circulation and the upper rad hose should stay cool. Then upper radiator hose should warm up quickly as thermostat starts to open and close to release some hot water to the radiator. After 15 minutes, it should be thoroughly hot, especially if you drive the car during this time. You should not be able to hold your hand around it for more than a few seconds, depending on how tough your hands are.

If not hot, your thermostat may be opening too soon and leaving the engine cool.

If theremostat and heater flow are okay, then check the movement on the temperature door(s) on the heater module inside the car to see if it (they) are moving full range.

If the one heater hose by this time is not really hot and the other cooled down some but still pretty warm, with the heater blower on higher speeds, you may have a flow problem in the heater.

Your lose of coolant might be from an internal leak again. Best thing you could do is an oil analysis to look for Na and K (sodium and potassium) in the oil after several thousand miles on the oil. I use Blackstone and I'm sure others do a good job. For $25 I found my coolant was getting into oil at a low level--seeping at the throttle body gasket it turned out. I was doing oil analysis at 7,000 on synthetic to see if it had more life in the synthetic oil. Got THE phone call from the guy suggesting to change oil frequently until I could have the upper and lower gaskets checked.

[Grimm]

Thanks for the tips. I just checked, and the reservoir is down to the full hot line. So the tech wasn't paying attention and filled to the wrong line apparently.