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Message |
Lawrence Coppari (Lawrence)
Junior Member
Username: Lawrence
Post Number: 135
Registered: 4-2002
| | Posted on Sunday, August 04, 2002 - 6:16 pm: | |
High coolant temperatures are due to several possibilities
1. Air in system
2. Stuck thermostat
3. Radiator not doing what it should be doing (turn on heater full blast to see if temp drops)
4. Water pump not putting out what it should be putting out waterwise due to corrosion making clearances larger than they should be (my porshe did that) or belt is slipping
Coolant should come out of thermostat bleed when engine is running. Mine certainly did. I forgot to tighten it after replacing water pump on major service.
You could remove thermostat and put in pan of hot water with a thermometer. Ensure it open at designated temperature. It ought to be stamped on it somewhere. Your can easily see it open.
Water pump might not be putting out proper volume. My Porsche did this to me. It wanted to overheat at low rpm. Old coolant is corrosive. Clearances might not be right.
Radiator could be clogged either interally or externally. Turn heater/blower on full blast to see if it lowers temperature.
Make sure there is no trash on your radiator fins.
Area is of utmost importance on these things. Radiator internals could also be clogged given the age of the car.
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Greg Owens (Owens84qv)
Member
Username: Owens84qv
Post Number: 494
Registered: 10-2001
| | Posted on Sunday, August 04, 2002 - 5:35 pm: | |
Ken, I placed a "how to" in the Parts & Service section on this site for replacing your antifreeze. You could probably use the same procedure for what you are trying to do. Open up both bleed screws and pour antifreeze into the expansion tank. Pour slowly. Have someone else at the radiator to watch it pee. As soon as the radiator starts to pee, close that bleed screw. Continue to pour radiator fluid until the thermostat begins to pee. Close that bleed screw. Continue to poour until the fluid level in the expansion tank is about 6cm below the neck.
I would be a good idea to replace the thermostat if there are any doubts about its condition.
Hope this helps. |
Steve Magnusson (91tr)
Member
Username: 91tr
Post Number: 890
Registered: 1-2001
| | Posted on Sunday, August 04, 2002 - 4:16 pm: | |
"What am I doing wrong?" -- nothing. Just add coolant to bring the level up to full and keep bleeding both places until (mostly) coolant appears, then maybe repeat a couple of times over a few days. After that, bleeding the radiator every couple of weeks should be enough to keep this in good shape.
When your car is running hot (230/230) have you (carefully) felt the radiator hoses near the radiator to confirm that hot coolant is actually circulating thru the radiator (i.e., the thermostat valve is working right)?
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Ken Ross (Kdross)
Junior Member
Username: Kdross
Post Number: 103
Registered: 2-2002
| | Posted on Sunday, August 04, 2002 - 3:20 pm: | |
I am a real idiot when it comes to mechanical work, so please be patient with me. I have a 1985 308 that appears to have a lot of air in the radiator system. This morning I started the car and let it idle for 5 minutes, and then turned the heat on. I then loosen the thumb screw on the radiator to bleed the system. It took about 2-3 minutes for all of the air to exit the system and I then closed the thumb screw. Unfortunately, my car is still running hot at 230 degrees for both the water and oil. When I returned home I checked the archives and learned that there is a second bleed screw on the thermastat housing. When I loosened that screw nothing happened. No air and no anti-freeze. I then opened the thumb screw on the radiator and a lot of air come out with a little anti-freeze. This continued for about 10 minutes until no air or anti-freeze came out. I also noticed after I shut the car off that my reservior level is very low because so much anti-freeze ran out of the bleeder screw. Totally disgusted I closed everything and called it a day. What am I doing wrong? Woudl someone please provide me with instructions for Bleeding a radiator for a 308 QV for idiots. Thanks.
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