Overheating...

This is a confusing one...
Ok, I'm looseing water out my overflow, I mean ALOT of water... I loose about a gallon of water in about 10 miles...
it only does it when I rag on it...
but if i drive it normal I have no problems...

here is what I have done,
I had a block test on it to see if the heads where warp or gasket shot... but the test turned out good...
(I knew it would, They are built heads with a multil layer gasket)

replaced thermostat, after that completely removed thermostat, both times still did the same thing.

I've flushed the system twice... still does it

I've got a higher PSI Radiator cap... didnt help.

this is whats happening, the system is get wayyyy over pressured, causeing it to blow by the cap and go out the over flow...

what causes this? It doesnt over heat until I loose about 1 1/2 gallons...

the only part of the intake that is connected to any water sorce is the throttle body... I havent really checked it for cracks... but I dont think that is it.

any Ideas...?

the only thing that would pressureize the system that much is a blown headgasket or cracked head. but you said you checked both those things so...does your coolent look contaminated at all? your oil look contaminated at all?

that really sux man. good luck figuring it out.

Bro the exact same thing happend to me, I thought my car was farked, Everyone was telling me it was my gaskets etc Water was pissing out of the overflow hose, in the end it was actually my main radiator fan, Get an Auto electrician to check it even if it looks to be going, is it going when the car overheats???? I bet that your problem is as simple as that.....................

nope... fans are after market...

does your coolent look contaminated at all? your oil look contaminated at all?

Nope already checked... Looks great... I take really good care of my car.
when you have over $60,000 invested and all my time invested I tend to be good at maitenence.

Make sure they are working!!!

Make sure they are working!!!

I did loooooooong ago... Trust me I wired them in my self... I have them on all the time as well... both turn on when the car turns on.
and I have a puller fan on my oil cooler and and small pusher located on the fire wall behind the rear turbo (I have no heat sheilds, I used alot of heat wrap)

Its just that mine were going when the car was stoped or there wasn't much load on the engine, and as soon as I gave her hell, The fans would stop under load. I'm sure its your fans, I would get an autoelectrician to check your fan motors.........................

I understand your theory and all, but Ive install many of these fans (MVPMotorSports mechanic <<<<<<<< )
Plus mine are reasently new because I had only one at first but my bigger trubos I reacently installed melted the main one... so I got 2 matching ones.

But I will look into it, Ive added it to the list, I really dont think it is, but tomorow at work I'll throw my car on the dyno and see if thats the case.

The reason why I rule your theory out is, that when I do give it hell I never over heat, and I rarley do but when I stop and look under my car it looks like it is pissing... I would understand if you gave it hell and the car overheated causeing the water to boil and pressureize the lines... but mine doesnt overheat...

If you are at normal temps and overpresurizing your coolant you are either getting presure added from somewhere or not holding the presure.

I would try a different radiator cap, just to make sure your high presure one isnt bad. And I would do a compression test on the engine, which it sounds like you may have already done.

I have done both, changed cap, and compression test.
I think I'm going to removed my throttle body to check for any cracks...

You could always try buying some Evans NPG+

Ive heard nothing but good things. If you still get overflow with that stuff then you deffinatly have something adding presure to the system other than just heat.