renvagn

Hi
Just did tires, air filter, oil and filter, plugs, wires. rotor, cap, brake fluid and coolant on Saturday on my 2 wk. old 89, 951 ( fuel and brake lines are currently very corroded and seised up) Since then my coolant temp has bounced from middle to 3/4 mark and the previous 2 weeks it never even got to the middle line. After looking at previous threads, do you think there is air in the system? My mechanic/friend dumped it the way he does my daily drivers(drain, plug and fill) I don't have a Haynes manual yet and not sure where the bleeder valve is and how to properly do this. The coolant is filled to the low middle point of the resevoir and I took off the cap and let the car run with the heater on for 10 minutes hoping it would push the air out. This seemed to help some what.
thanks

nathan944

You have to bleed at the highest point of the system. There is a bleeder screw where the top rad hose goes into the head. The way I do it is take that out and fill until it come out, then run the car with the heat on untill all the bubbles are out. Good luck.

renvagn

I just replaced the coolant, are you saying I have to dump it and refill in the manner you mentioned? Also is this water wetter any good? Project 951 in European car stated it drastically reduced engine operating temp.
Thanks

TheMAXX

You don’t have to remove the coolant to bleed it. But you will need to add more using most methods of bleeding it. It definitely sounds like you still have air in there. It can take a couple of times (of bleeding it) to get all of the air out.

Serge944

Fastest way to bleed is to do mouth to mouth on the expansion tank. Although, bear in mind that antifreeze is a toxin. (Don't swallow )

joseph mitro

in this photo the bleed valve is located immediately under the fuel rail cover where the red arrow is pointing. you have to open this valve to bleed the air out of the coolant system. it takes some time, the car will probably overheat while you're bleeding until you get enough coolant to make the fans come on and the thermostat open

nine-44

My 8V cars always take just at 2 gallons total to fill them. I use that as rule of thumb. I let the system buld a little pressure and open the bleeder, watch out for hot coolant and steam. When you get a constant flow of coolant and no air, you are good. Also, don't forget to turn the heater on to circulate the heater core as well. I've had some nasty air pockets hold up in there too. Good luck

RMills944

^^
like Andy said - warm up the engine so the fluid is flowing, then slowly crack the screw till it starts leaking a little. Let it go till it starts leaking a solid stream of fluid with no air bubbles. It's easy to do and just make sure not to let the resovoir empty out on you.

Charlotte944

OK, here's the procedure:

NOTE: This is performed with a COLD engine!

1. Get the car in a "nose high" attitude by either jacking up the front, or parking on an inclined driveway.
2. Set the heater controls to full hot.
3. Start the engine and let it run for 30 seconds or so to circulate coolant through the heater core.
4. Stop the engine.
5. Find the coolant over flow hose. If necessary, loosen the expansion tank mounting bolts (had to do this with my 951) and pull the hose from behind the expansion tank.
6. Remove the expansion tank cap.
7. Use a 12mm wrench to open the coolant bleeder bolt.
8. Put one hand over the expansion tank neck and gently blow into the coolant over flow hose. When you see a solid stream of coolant at the bleeder, close the bleeder.
9. Add enough water to the expansion tank to restore the previous coolant level.
10. Install the expansion tank cap, start the engine, let it run for 30 seconds, shut down, bleed, top-off. Repeat as necessary.
11. Find another mechanic.

The bleeder bolt is located in the coolant fitting (gooseneck) at the front of the engine.

renvagn

Thanks, I want to confirm your instructions. Once I complete the process once, do I repeat the process the same way...run for 30 sec c/ heat on, turn off, blow in overflow hose, bleed ect. Or can I just follow your step 10.

fezz

what cliff said, and I found it helps to fill the block from the head spout ( it will take a gallon) and fill the radiator from the expansion tank with another gallon.
running the car on an incline, nose up, will send any air bubbles up and out.

RMills944

My way's simpler :-p lol