Running hot, heater blows cold, my situation

[cratica]

Ok, yup, read through a bunch of posts but thought I would throw this out there in case someone has had the exact same issue.

Just got this particular 1997 GTS, previous owner couldn't drive well apparently and went on an off-road excursion, collecting lots of mud and grass. That's all cleaned up, new tires, repainted front bumper, side sills are ordered, etc... While I had the fascia off I noticed there was no coolant in the overflow. I poured water into it to check for leaks and it was cracked on the bottom so I've replaced it. Filled it to the min level, filled the pressure tank up as well.

Car runs great, but it runs hot. It runs between the last click of the 3 to the next click on the right, which I assume is either 225/230. It hasn't gotten over that last click (not the red one but the one before the red one).

Additionally, when I tried to burp the air out of the system, I turned the heater on, all the way hot and tried various settings such as defrost, heater low, etc... but only cool air blows through. I have "burped" the car 2x (once after refiling the overflow bottle again) and the heater still blows cold. What I mean by burping is that I raised the passenger front of the car up with a jack, took off the pressure cap, made sure there was plenty of coolant, started the car and squeezed away on the upper rad hose until it was too warm to touch comfortably. Replaced the radiator cap, squeezed a bit more. Am I missing something?

The temp will stay at just over the last of the 3 center temp marks when sitting idling in my driveway.

Ambient temps have been hot, in the high 90's.

So... is the hot running condition and the lack of hot air out of my heater related? Is it most likely due to air in the system? Or, are they unrelated?

If anybody who lives in the Austin area wants to come take a look, please feel free!
I'm in the Brushy Creek area of N Austin, near Round Rock...

 

[Phun70]

You have an air pocket in the heater core. I would disconnect the heater hoses at the core and don't put them back on till fluid comes out. Start with the lower of the two and then reinstall. Then do the same for the higher of the two hoses. then rebleed at the surge tank. That should take care of it.

 

[dave6666]

That really isn't that hot for just sitting there. What is the temp when out on the road at 70 mph? And with the coolant tanks full driving it is a great way to purge the air out. The Gen 2 system is self purging to a degree. On your heater are you sure the control valve above the heater core (under the hood) is opening?

 

[cratica]

Well I just took it down to my corner garage (LAMB's automotive) where I have taken all my cars through the years and am going to let them flush the system and fill it with a pressurized system. We'll see if that fixes these issues... Will post back in a few hours...

Dave... not sure if the control valve is working but will look at that if the above doesn't work. Temp on the road at 70 is about the same. In traffic out of the road or going slow its closer to the far right mark (last white one before red). If I get on it, it will hit that last white mark.

 

[plumcrazy]

sounds fine to me

 

[cratica]

Bummer. This *****. Fluid was flushed and refilled at shop.

I drove it a few miles and the temp is still the same, actually went just past the last white mark and stayed there. No heat coming from heater either. Just ambient/residual air from the a/c being on.
Temp here is close to 100 today, it's really hot outside but it should not be running this hot. I drove her last night when the temps were in the 80's and the temps were still nearly the same.

 

[cratica]

btw, the temp was on the 3rd center tick when idling, sitting but goes up to the last white tick and just beyond when driving, little traffic, 45-60 mph, stopping for the occasional light.

 

[cratica]

my c6 runs about 195-205 temp. this car is running whatever that far right tick is (225-235 or thereabouts)

 

[cratica]

just went out to check the heater valve as dave suggested and yes, the heater valve moves on the core...

When I turned the switch to the on position, I also checked the temp and it's up to a needle width away from the red mark I guess from heat soak. This is not good. This is ridiculous.

 

[dave6666]

Stuck thermostat? Is the upper radiator hose hot?

 

[cratica]

yes, the upper radiator hose gets real hot

 

[cratica]

the temp does fluctuate a little so I think the thermostat is opening

 

[99 R/T 10]

Just a guess, but it could be your waterpump has failed. Since it is not circulating fluid, the heater would not work. Just thinking out loud..............................