SOS - Overheating after T-stat and water pump replacement

[dpatel710]

Long read but I did a lot of work and am at the end of my rope figuring out what is wrong here - I need some help! 

 

Did a major maintenance service on the 04 CTT as it approaches 200k. Replaced all the various bits on the front of the motor with the car in service position. Pulleys, tensioner, rollers, alternator, ac compressor, water pump, thermostat, serpentine belt, upper+lower radiator hoses, diverter valves, etc

 

Vacuum bled the system and tried to burp it but it is running hot and holding at the 3rd bar. Tried the heater at max but it is only blowing cold air.

 

Figured the coolant is blocked somewhere so I went onto to do some troubleshooting:
- Checked and verified operation of the old and new thermostats in the water pipe housing with boiling water
- Checked all hoses for kinks, none found
- Checked coolant after run pump in drivers side wheel well. Pump is running dry, no coolant is flowing through those hoses.
         - To check for blockage at those hoses, I removed the hard lines and ran water through them. No block.
         - I then took the garden hose to the vehicle end of the hoses to check for flow, all good.
- Seemed like no coolant was flowing from the water pump so I pulled the upper hose while the car was running. I figured the upper hose should spray out coolant but nada came out. Those hoses have no blockage and the radiator pours fluid out so its filling/draining.
- Swapped out new water pump for old water pump again...still no dice

 

Car was working fine prior to bringing it in for maintenance. I'm stumped and am calling on the collective brain trust for help, please! What do you guys think it could be/have any troubleshooting tip? Can someone color in info on how the cayenne cooling system works? I understand the basics for a normal car but the CTT has a bunch of extra stuff in it.

[wizard]

I'm not familiar with a Cayenne, but, just on a hunch, have you tried filling the radiator directly through the appropriate hose to see if there's a lock there?

 

Is the new water pump a Porsche part?

 

[dpatel710]

More research shows that the cayenne's cooling system is a PITA to bleed right. Ordered the proper vac bleeder and will try again. If that fails, I will try "rocking" the car to help burp it. 

[dpatel710]

I have bled the car system several times. The uview airlift cooling bleeder worked well and did the trick for getting the air out. Pulled vac down to -25 and filled slowly, idled the car with the cap off up to operating temp, and once operating temperature was reached I put the cap back on (per instructions in the uview kit).

 

New issue - Car only blow heat at idle. Temperature gauge is dead steady in the middle at all speeds. Anything over 2k rpm and the car starts to blow cold air. What the heck??? Could it be the secondary electric coolant pump going bad? HVAC system worked fine before the tstat and water pump replacement. As the above post shows, tstat and waterpump have both been replaced and are operational. 

[dpatel710]

Turned out to just be stubborn air bubbles in the system that even the vacuum bleeder couldn't get out. I was able to bleed it the old fashioned way with a large funnel stuck into the reservoir and A LOT of hose squeezing. 

[ekstroemtj]

Hi, just read your post. Having the same problem. Could you explain please how you solved it. Tank you