airtraffic

Hey folks,


Just replaced water pump, timing & balance belts..

My car is running smoothly, but very warm. On a highway run, 70 MPH, the level was at the upper mark almost the entire ride with a 70 degree outside air temp.

When I installed the coolant, I used a pressure tester from my local auto parts store I was able to apply pressure to the overflow tank until I saw coolant come out of the bleeder bolt. I thought I would have ensured I eliminated air that way.

When I turn the heat all the way up, the temp comes down to the lower mark on the temp gage, where it was before the job.

This afternoon, I opened the bleeder valve, started the motor and let the car come up to temp. eventually the temp came up tot he upper mark on the gage.. Not overheating, but definitely hotter than it should be. I got some water out of the bleeder, but not a whole lot.. I felt the upper metal radiator hose and it was hot. I felt the lower rubber radiator hose and it was COOL! This is bad, right? I thought perhaps there was an air bubble here, and that perhaps by squeezing this hose, I could push some air out and get water going. When I squeezed, some air/liquid would spit from the bleeder, but not a lot. The temp did not go down to the lower mark during the test. When I shut down the car, some water/coolant did come out of the bleeder, and I closed the valve.

Is there a way to verify that the water pump is indeed circulating coolant, and is there a way to make sure it is flowing through the entire system? I assume the lower hose should indeed be hot?

Thanks in advance!

SID443

Turn your heat on all the way while bleeding that will help.replace thermostat to b on the safe side,also theres a vw fan swith that will turn your fans on a few degrees earlier

airtraffic

Yes, I did run the heat while bleeding.. I pressurized the system while I was initially filling the cooling system using a cooling system pressure tester borrowed from a local parts store, but I didn't realize I should have had the bleeder port open while filling.

While I was pressurizing the cooling system before initial start-up I saw liquid coming from the bleeder valve, but I suspect the fluid was going through the upper radiator hose and out the bleeder. So, somehow I think I am not getting water between the thermostat and the lower radiator hose. If I squeeze the lower radiator hose with the bleeder valve open, I can hear air escaping from the bleeder valve when it's cracked open.

VirginiaF1

Air, where are you located?
Can you get the front end of the car up at least a foot to help release any trapped air bubble?
Did you unscrew the little bolt on passenger side of block to expel old coolant?

(Thanks Fletch!)
Did you stovetop test your new thermostat?

airtraffic

Hmmm.. No I did not open the drain on the block. Now that you bring up that point though, I find it strange that the old coolant was green, and the new coolant is the Porsche coolant. (Pink) I was expecting the two to mix and that I might have to flush out the coolant again to get rid of all the old green coolant, but the overflow tank has nothing but clean pink coolant in it. So, is there green coolant circulating in my heater core cooling the engine when I have the heat on and the pink coolant is not really circulating at all? And sadly, no, I did not stovetop test the thermostat before use.

I'm in Pennsylvania.

airtraffic

So on my way home from work, I had the heat turned about a third of the way up, (20C) and that kept the temp needle comfortably right in the middle of the gauge all the way home. ( 1 hour trip) I experimented, and whenever I'd shut the heat off, the temp would quickly climb to the top mark on the temp gauge. I found I could not turn the heat down below 18C without the water temp climbing.

So, looking at the thermostat housing on the water pump, it appears the water supply for the heater taps off just upstream from the thermostat.. (Or between the pump and the thermostat) So it appears that if the thermostat doesn't open, the water will still flow through the heater core, yes? This is why I was able to use the heater core as my substitute radiator?

I am wondering though, where does the return from the heater core go?

I am really hoping it's possible I still just have air in the lower radiator hose, as some have said it takes days to get the air worked out of the system. Or does it look like I have to go back into the thermostat. (Ugh!) Is there a way to prove either way before tearing into thermostat?

airtraffic

Appears temp fluctuations are indeed caused by air still trapped in the hoses.. Took more air out of the system today. Lower radiator hose is starting to fill with coolant. As many have said, seems to take a few days to work the air out.