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PCinDC · 03-18-2017, 03:24 PM

Hi guys,
I'm having some issues with my cooling system and need to run some ideas by you all in the hopes you can help me get to the bottom of this.

Caveats - I've read most of the threads here, and tried quite a few of the recommended steps.

Here's the synopsis.

Car was loosing coolant, relatively slowly
Noticed coolant in the trunk area and diagnosed problem as a bad overflow tank
Replaced overflow tank and all of the spring clamps with worm gear hose clamps
Car ran fine afterwards, but I noticed a coolant smell fairly routinely.
PO had told me the water pump was an aftermarket unit replaced around 50k miles ago
I figured this was as good a time as any, so I replaced the waterpump and thermostat with genuine Porsche parts
After doing so, I notice that the heat no longer works
After doing some research, I realize the heater core is 'always hot' and that this problem indicates an air pocket in the coolant system
I did some further research and realized it might have something to do with a superseded overflow tank cap.
I replaced the overflow tank cap with a -04 cap
While doing so, I inspected the bleeder valve and all looked ok. I did buy a replacement to have on hand if needed
I attempted to manually bleed the system via the bleeder valve, but still had the same symptom regarding the non-functional heater. At this point, the car can no longer make it 'around the block' which is about a 5km track without coolant temperatures reaching 250F
I decided to buy the UView vacuum bleeder, drained the coolant and applied vacuum
I was only able to draw 15 pounds of vacuum, but the system held vacuum indicating no leaks
I refilled the system via the vacuum method and drove the car around the block
Heater still does not work, but coolant temperature does not get to 250 (maxes around 230 while driving, and when parked back in my driveway, coolant temp declines to around 200
With the car up on ramps, and running, I try to manually 'burp' the coolant system by squeezing the coolant hose on the driver's side of the car at the front of the engine - it's cold, whereas the hose at the thermostat side is hot
I think, perhaps the brand new thermostat is bad, or stuck, so I remove/reinstall and inspect it - no obvious problems.
I re-do the vacuum fill method, but the vehicle still has no heat

At this point, I'm not sure where to turn next. Is it possible that I have a blockage in the hose leading to the front of the car? Any other thoughts on where I should be looking?

Thanks for your help guys.

03-18-2017, 03:24 PM	#1
PCinDC Registered User Join Date: Apr 2016 Posts: 61	Help diagnosing cooling system issues Hi guys, I'm having some issues with my cooling system and need to run some ideas by you all in the hopes you can help me get to the bottom of this. Caveats - I've read most of the threads here, and tried quite a few of the recommended steps. Here's the synopsis. Car was loosing coolant, relatively slowly Noticed coolant in the trunk area and diagnosed problem as a bad overflow tank Replaced overflow tank and all of the spring clamps with worm gear hose clamps Car ran fine afterwards, but I noticed a coolant smell fairly routinely. PO had told me the water pump was an aftermarket unit replaced around 50k miles ago I figured this was as good a time as any, so I replaced the waterpump and thermostat with genuine Porsche parts After doing so, I notice that the heat no longer works After doing some research, I realize the heater core is 'always hot' and that this problem indicates an air pocket in the coolant system I did some further research and realized it might have something to do with a superseded overflow tank cap. I replaced the overflow tank cap with a -04 cap While doing so, I inspected the bleeder valve and all looked ok. I did buy a replacement to have on hand if needed I attempted to manually bleed the system via the bleeder valve, but still had the same symptom regarding the non-functional heater. At this point, the car can no longer make it 'around the block' which is about a 5km track without coolant temperatures reaching 250F I decided to buy the UView vacuum bleeder, drained the coolant and applied vacuum I was only able to draw 15 pounds of vacuum, but the system held vacuum indicating no leaks I refilled the system via the vacuum method and drove the car around the block Heater still does not work, but coolant temperature does not get to 250 (maxes around 230 while driving, and when parked back in my driveway, coolant temp declines to around 200 With the car up on ramps, and running, I try to manually 'burp' the coolant system by squeezing the coolant hose on the driver's side of the car at the front of the engine - it's cold, whereas the hose at the thermostat side is hot I think, perhaps the brand new thermostat is bad, or stuck, so I remove/reinstall and inspect it - no obvious problems. I re-do the vacuum fill method, but the vehicle still has no heat At this point, I'm not sure where to turn next. Is it possible that I have a blockage in the hose leading to the front of the car? Any other thoughts on where I should be looking? Thanks for your help guys.