After driving my fd, sometimes I get a water leak from my resevoir and sometimes I don't. I just replaced my Pettit AST cap with a 16lbs. Stant cap, my idle is fine, my vaccume reads 16-18 at 900-1000 rpm, I've never overheated, I have excellent throttle response, and I have a koyo radiator mounted vertically. When I pressure test my cooling system, the friggin thing holds pressure up to 16lbs. but when I fill the neck up with water, the water just flows really freely from the neck to the ast, to the overflow. I don't get it. has anyone else experienced this same problem, and if so, how did you fix it? Feedback is greatly appreciated.

Oh, also, I did the champagne bubble test, and no bubbles came up. Whew!

Anyone?
TIA.

 

Also, I can hear that my water pump is gettin a bit squeeky, but there is no water comin out the weep hole.
Can these things go bad without water coming out the weep hole? If so, would that explain why there is no water circulating throughout my cooling system, and thus flowing straight to the overflow?

 

I have a similar problem, In the filler neck no mater howmany times I fill it to the top it allways drops like 1 or 2 inches down (while checking the coolant the next day). I also did the champagne bubble test and its fine, and I dont have any coolant leaks anywhere. What could be the problem?

 

Forgot to mention this one time it went so low that my coolant buzzer went off.

 

Yeah, it'll do that when the coolant level reaches below the sensor, you should be okay as long as you didn't overheat the sucker.

 

I'm hoping that something like this would be a textbook case of a waterpump that is on it's way out.

 

Allways watching that damn temp sensor, I think this car is going to drive me insane.

 

Water pump huh, well add that to my long list of things to replace this winter when I put the car away.

 

Everyone, could my radiator be clogged? Would a good flushing do the trick?

 

I think I can help both of you.

Series7, you should be running a 13 psi pressure cap, 16 is way too much. Things have a tendancy to explode at this preasure.

I had a similar problem to both of you and I found that my resiviour return line was bad. This line doesn't get pressure tested during a coolant leak down test and can collapse or leak causing weird coolant problems.

Replace the line and get a 13 psi cap and see if that helps your problem.

JCW

 

FPG, thank you. I will do this asap. Tonight, in fact!!!

 

Me too
I think a new 2 row radiator will fix my cooling problem.

 

If you are replacing it the bigger the better, the more surface area the radiator has the better it will perform.

This thread describes the methods of achieving better coolant temperatures.

https://www.rx7club.com/showthread.p...light=radiator

 

My water pump was recently squeaking but not leaking. After I ordered a new one, I pulled it off and it looked like the vanes were slowly cutting into the housing.. (only a small amount) It was like the bolts weren't tight enough to hold the pump in place, and the force of the belt pulling between the main pully and the air pump had shifted the waper pump cover to the left. The pump was fine though. Just needed to be repositioned.

 

NewBD, thanks for the insight. So are you saying that I don't need to replace my water pump?

 

I'm saying that there's a good chance that you don't. Pull it off and see if it's still making noise when it's free. Here's a pic of the damage on my housing.

 

SERIES7, there's really no reason for the water pump to even come into the equation with this issue. Check the return line.