Cooling problem.

[Silent Smith]

Hello all, I recently purchased a 89 TT with 136km on it. The car sat for a number of years and when I inspected it the low coolant light was on and the temp gauge would go skyhigh as soon as the ignition was on (even on a cold motor/not running). I topped up the coolant in the rad and over flow and ran it a few times. Gauge still read skyhigh as soon as ignition turned on. I installed a new coolant temp probe and it seems to work fine for the first minute or so, it will gradually climb then once it hits 1/4 warm it skyrockets. I've tried lifting the front end and running with the cap off and taking off various hoses to try and bleed the system but nothing has helped. The motor runs fine and does'nt appear to be over heating (rock solid idle and pulls strong). On a hot start up it putters for a few seconds but I think that could be heat soak and in the mornings you can hear coollant rushing around.It pased emissions testing yesterday with almost zero emissions, so I don't think it would be a BHG. The upper rad hose never feels firm and theres no bubbles in hte coolant with the cap off

Any ideas?

 

[mrnickleye]

You may have to do this a couple of times....

Originally Posted by mrnickleye

Mine had it, too. Air trapped in the heater core, cause its higher than the radiator cap.

Make sure heater water valve is open. I would by-pass the vsv for this

***note... water WILL pass thru heater core when thermostat is closed, (on a cold engine)***

Not too hot engine. Heater controls in max hot, with fan on low setting.

Using ramps, or jackstands, Raise the front of car as high as possible (I went 3 feet on mine, till the exhaust pipe tip was almost touching the ground).

Remove cap and drain off (at drain plug into pan) coolant until you can see the radiator core inside cap area. Tighten drain plug. Start engine and let idle for about 20 min. until nice and warm.
You can raise the idle up to about 1000rpm to make the water flow better.
***Note...Don't rev the engine, as it will cause the coolant to shoot out like a whale spout***

The trapped air will be forced out because doing this proceedure makes the core lower than the radiator cap.

Shut off engine, pour drained coolant back into radiator, install cap (new prefered). Lower car. Fill overflow bottle 1/2 way. Test drive.

No more waterfall sound ? Good !

I had to do mine 2x to get it all out. Next day, Check and fill 1/2 way the bottle, as the removed air will be replaced by coolant, so bottle may be low.