Ok I just got My rebuild today drove it from the shop about 1/4 mile and the add coolant light came on, I turned around tool it back to the shop, Mechanic said it was the fill cap spring wasnt working he changed it and it stopped. I drove it on the highway about 20 miles or so no problem drove great I get off the highway get into some trafic and it starts going off again!!! The shop is closed and Im supossed to drive home tonight but I dont want to drive it. the over flow and radiator are both full. ANY IDEAS???
Thanks Alot

 

bleed the coolant system. It was not done properlly

 

well Im at my girlfriends and I dont have the tools to do it....would I be ok driving it about 20 miles on the highway back to the shop??? When I was driving it on the highway befor it wasnt doing it and the temp was normal.
and how do I bleed the coolant???

 

You dont really need any tools. Take off the cap on your tstat housing and let the car idle (careful removing the cap is the system is pressurized!). Leave the heater on full blast and gently squeeze the lower rad hose at the same time while it is idling. May take 10 minutes or more.

 

I just read a thread that said,


No, you use the bleeders and bleed the air out.

Unscrew the highest bleed. Fill radiator, put the cap back on the radiator, squeeze the top radiator hose a couple of times, until coolant is flowing out the bleed. Put the bleed in, take the highest point cap back off, fill to over flowing. cap on. squeeze a couple more times, remove cap fill, repeat until you no longer hear air bubbles moving when you squeeze the top hose.

At no point should you have to run the engine with the cap off.

Should I do this with the engine hot?? or does it not matter

 

Hey man, one easy thing to do is to check the one-wire harness that runs from the level sensor on top of the rad. Maybe the rebuilder didn't push the connector ends together good enough or something. The connector is down by the air filter area in most cases, or by the side of the rad...

If the rad and overflow are both full, it may be the wiring...

I have never, ever had to use the bleeder screw at the rad to bleed my systems after a rebuild/ coolant change over the years. Just use the high point cap (t-stat housing on most cars) after she cools down. If it's full there, it should be full everywhere, unless your water pump's crapping out on you...

 

Thats another idea I had if the water pump is craping out and not pushing enough water during normal driving would it possibly be working better in higher RPMs when Im on the highway?

 

Some people do it different ways and I'm not saying any of the above info is wrong but I always have better luck doing it the way I described above The highest bleed valve for your car would be the flat cap assuming your car is s4.

Plus how do you think people with s5 waterpumps and s5 koyos bleed the air out without the metal neck s4s have on the thermostat housing and no bleed valve on the radiator. Gotta leave the rad cap off. You would want to do it with the engine hot so the thermostat is open and all of the coolant is flowing unless you want to take out your tstat.

 

But you should if you want to do it right. By far the most effective way to bleed air out of the cooling system is to run the engine with the filler cap off. This technique is as old as the hills. The moving water will quickly move any air bubbles up to the filler. This is way better than simply squeezing the radiator hose a few times. How's that going to move air bubbles in the engine?

 

jason is right....
i just fill it up all the way, start the car, and just keep adding water till i cant add anymore....

 

use the bleed screw on the radiator. If that doens't work try replaceing your sensor. When I got my daily driver the coolant buzzer was always on. I finally replaced my sensor and it went away.

 

archive has good stuff

https://www.rx7club.com/2nd-gen-archive-72/filling-coolant-after-rebuild-383818/

 

I went out this morning to bleed the system, I drove the car around for about 20 mins to warm up the engine and nothing let it idel for another 5 or 10 mins and no light no buzzer. befor I drove it I disconnected the plug on on the fill neck and pluged it back in to make sure it was good. could the air worked its way out overnight??? could the plug not have been making a good connection???
Thanks

 

I think it's the fact that you kept driving it around and checking/ adding coolant that finally got it "good to go" now

Keep an eye on the level in your overflow tank- if it doesn't change any over the next couple of drives, you're free and clear to celebrate a job well done...