Hey guys, I have some type of coolant issue and can't really figure out whats going on. For some reason it sounds like the coolant is boiling in the AST after the car warms up, when I drove it home from buying it all the gauges seemed fine, the water temp never rose past the half way mark and normally stayed under it. I was thinking maybe since it was hot out and the ride home did take about and hour or so the temps might have gotta alittle hot, but I took out yesterday morning for about 15 - 20 minutes and it was doing the same thing, the boiling noise from the AST. I checked the coolant and oil levels, they are both fine and I haven't been able to find a leak anywhere from any hoses. I have read on other posts some people have had this problem but it seemed no one gave a real clear cut answer as to how to go about solving this mystery. I thought to test the coolant to see what the ratio is (which should be done later today) and I've ordered a aftermarket radiator. Also something else I was wondering, should the AST be full of coolant? And if anyone is wondering the mods on are...

-Stainless steel DP
-PFS catback
-m2 carbonfiber intake box

other then that its a 1993 twinturbo, remanufactured engine with orginal turbos, if I left anyone thing out just ask!

another thing I just thought of the stock coolant gauge noramlly stays under the halfway mark (I know they're unreliable) and never raises past the half way point.

 

Are you sure your coolant is a good mixture? If you have too much water it'll boil. And I really hope you havent added any tap water in there. Thats my best guess. Yes, your AST is supposed to be full of coolant.

As for the temp gauge, it wont even start creeping till you get to the 110's C. It usually stays a hair below middle. Thats not the best gauge of your coolant temp. That guage measures block temperature. I've run for an hour at 107C and the gauge didnt budge, but it doesnt mean 107 is a smart temp to be running at.

 

I just checked the mixture and it read 40% coolant, and i haven't added anything, so I guess the next step after i get the radiator is a AST and temp guage.

 

i had the same problem and it was a leak. my hose from the filler neck to the overflow bottle was split and causing the noise. my guess is you have a leak and just can't find it. it may be small enough that you don't see any coolant dripping. try the same hose as mine first. i also remember an incident where that same hose was pinched and causing a similar problem.

 

Hrmm, ok, looks like I'll be going back over the hoses tomarrow, but tonight when I got home there was no boiling sound, and I made sure the car had time to warm up and everything.