Stanello

iTrader: (1)

I finished installing my Koyo radiator yesterday, and it ran nice and cool. Maybe 1/8th of the way up the gague at the most. Drove it for about 100-150 miles and everthing was fine. Today drove it for about 30 miles, when I stopped and shut the car off, I heard a BLURP BLURP GURGLEEY BLURPISH noise, like it was overheated. I get out, and coolant is coming out of the already full overflow bottle. The engine is not hot. The cooling system is not overfilled. I let the car sit for a couple hours and come back out to it, the overflow bottle is still full, and the engine is not sucking the coolant back in. If it is, it is doing it really slow. Does the way I have the overflow hose from the radiator into the coolant bottle matter? I've got an S4, and my coolant overflow tube comes off the thermostat housing. So right now the one off the radiator is just down into the bottle. Any help would be great, I'm stumped on this one, for now anyway.

jreynish

iTrader: (2)

How do you ahve the lines running to the cap on the overflow bottle is the Tab on the cap facing the front of the car or the rear?

yearrgh

You've got a pinhole leak somewhere in the coolant system. Pressure test it.

BlaCkPlaGUE

^yep.

Does the coolant buzzar come on after this all happens and you do not fill it again?

All I can think of is that the rad cap your using has a weak spring, or a bad seal, and or does not fit properly.
I don't know how well they fit on the koyos, but I'd personally stick to the one thats on the thermostat filler neck, as its designed to be used with the mazda one. That is, if the pressure cap flange on the koyo is not the same size...

jreynish

iTrader: (2)

if you have your hoses hooked up improperly on your coolant resevoir cap you will only manage to spew coolant out into the resevoir but not pull it back in, there is a one way check valve in the cap, for the overflow resevoir that is why I asked how it was hooked up and oriented.

13Beast REW

I'm having a similar issue after changing the upper radiator hose. Until I read this I'd actually given up on my motor and called the problem as being blown coolant seals since that is what I determined to be wrong with my FD. Now that I think of it though, my coolant temps stay regular, my coolant buzzer does go off, and the coolant in the overflow is not drawn back into the coolant system. Guess I'll look into the issue a little further tomorrow.

Stanello

iTrader: (1)

OK, there are no visible leaks, I checked this extensively during the install. Both radiator caps are new, 13psi caps. Before I went to work today, I took off the overflow hose from the radiator and plugged the ....nipple I guess I'll call it with a bolt to see if that was the problem. So now I've got it back to the way it originally was. When I got to work, I popped the hood and checked everything out. Not as bad as before, but still the same. Overflow bottle is full. After work, (7hrs), I popped the hood before I cranked it up, and the overflow level had dropped to about 2cm above the full line. Drove home, and it's about 3/4 full.

Edit: How do I go about pressure testing?