Coolant shooting out of overflow reservoir.

[84sithlord]

I have the aftermarket overflow reservoir (the one that comes with the Alky Control kit). I noticed coolant shoots out of it sometime. I did a compression check. all my numbers are good. what could cause this to happen? too much coolant? a leaking intake manifold? my oil was normal when i changed it last weekend. any thoughts? Thanks!

 

[big reazon]

either over heating a bad thermostat causing alot of restriction or your overheating.

 

[84sithlord]

ok. my scanmaster said i was running 162-165. my vdo gauge read about the same. i have gone through 3 thermostats. lol! been chasing this heating issue/coolant spill issue for over a year. i have new radiator, flex fan, water pump....i'll swap thermostats again. lol! thanks for the input!

 

[Slow91z]

Or a headgasket that only leaks under boost, been there, am there

 

[bison]

Compression entering the
Cooling system. Time to replace head gaskets. This is usually triggered by a good shot of detonation.

 

[projectmoneypit]

silly question but have you changed the rad cap. I have a simular issue with my hauling truck. It has a 7.3l idi diesel and does the same thing while idling but is fine while driving. Everyone says head gaskets but oil and coolant are clean and the blue dye combustion gas test never changes color.

 

[fmster]

2x on rad cap

 

[84sithlord]

thanks for the input guys. i want to do the chemical test so i can rule out the head gasket. i have a pressure relief rad cap. i will go ahead and replace that....its about a year old. i will let you know.

 

[fmster]

You said you have a new rad,is it a f body rad? Make sure you have the cap for the specific rad.

 

[84sithlord]

yes it is. i will. I know it is a stant and it seems to fit it...does advance have those chemical tests to check for exhaust gases in coolant?

 

[JayC]

Or a headgasket that only leaks under boost, been there, am there

This

I always wish for it to be something else. It never is.

 

[84sithlord]

 

[84sithlord]

these will seem stupid but the coolant still shoots out even when i'm not getting on the gas.....also it will run what i consider to be a good temp for a while (15-20) riding down highway. then, when i get off highway, sometimes the temp will go crazy. could this be air trapped in system or a blockage somewhere. i have used stop leak before in the radiator.

 

[JayC]

That's a head gasket. Might as well just face it. The wonky temperature is a tell tale sign. Ive seen that more times than I wanted too and its always a head gasket.

Sent from my MB855 using Turbo Buick

 

[84sithlord]

lol! my dang compression readings were good....dammit! lol! guess i'm going to face the music.

 

[84sithlord]

are you at the nationals this week Jay?

 

[84sithlord]

good news is, i've been gathering all the goodies needed for a head gasket change so i can start this weekend....

 

[Slow91z]

I've seen completely blow out head gaskets compression test good, a leak down test tells a way more complete story.

 

[84sithlord]

i've been thinking its blown for a while....my alky system was jacked as soon as it was put on the car.... i remember hearing knock when the system was first put on while running 21lbs of boost so i'm sure thats the problem.... guess this is the reason I do the work now and not pay somebody else!!!! hard lesson learned...if you want it done right the first time, do it yourself!

 

[84sithlord]

what is a leak down test exactly?