there is a tsb on the radiator cap, but its usually caused by a lifted head(which warps the gasket) or a warped/bad headgasket. what happens is combustion pushes past the thermostat into the radiator and once its full the overflow tube does its job. the issue is it constantly pushes combustion and the overflow tube can not draw the coolant back in. i actually just changed my gf's head for this very reason not too long ago

 

I am also having the same problem. I am running the headstuds below with an HKS headgasket. I have changed turbo setup and remapped the car on a 2.0LR 6262 setup using 33psi boost.

Are these headstuds strong enough?

http://www.maperformance.com/map-hig...11mmalloy.html

 

Iam using the exact same setup as you with the exception of the head gasket. I am using oem head gasket. I originally had a head gasket issue due to improper torquing. I replaced head gasket and had the head milled and then I started having overflow problems. I believe the radiator cap may have become damaged when the head gasket was bad. I replaced the cap and it seems to be okay now. Hope what I told you helps?

 

My overflow when cold is at the full mark. When at full temp it rises to just under where those small numbers are. Even when I stay out of boost.


I'm no expert but from my experience, the overflow always rises a noticeable amount when the coolant heats up.


The-Evo, did you go with another OEM rad cap? Those 1.3's put extra stress on the cooling system.

 

Yes HG is blown, you are building excess pressure in the coolant system and it needs to go somewhere.

 

Yes I did. I bought a mishimoto radiator and it came with a new 1.3bar radiator cap with it.

 

An update on mine: still pushing after new cap and t stat. Gonna do the head gasket next month. F frustrating issue as i have great compression and no fluid mixing but i don't see what else it could be at this point. Any other thoughts before i take the big plunge?


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Sorry to say, but at this point, it's definitely a head gasket issue. What head studs are you using. Is it a built motor/head? What psi are you pushing?

 

Factory 9 everything, except for a TBE and a tune. It's at about 18psi-ish I believe and it is still on the factory head bolts. I bought head studs and a head gasket. Weird since it never pushes coolant when boosting, only when it's up to full operating temp and I drive it long distances.

I have a sneaking suspicion the PO used stop leak on it to get it by until he could sell it (to me) but there isn't quite enough residue in the overflow tank to know for sure. Oh well, it needs head studs anyways.

 

Do you have any oil residue in your coolant? It should collect at the top of the radiator neck or in the overflow bottle. Mine looked like small specks of dirt at first.
I made this thread so you can see what it looks like. https://www.evolutionm.net/forums/ev...ption-3-a.html

 

Nope no oil in there. Wish it was that simple. One of the first things i checked for.


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Update for you guys.........mine was the Rad cap.....Greddy 1.3bar Rad cap has done it for me

 

my experience is Cometic HG are not very good at least on the Evo platform. get somthing with a stopper layer or integrated fire ring . somthing like the Power enterprise HG or Cosworth HG . i have had the best luck with those two HG on 30psi 582WHP VD . running 10.92@130.9mph. on street tires 1.8 60 foot. the Power enterprise HG has lasted over a year of racing now . never push any coolant at all ...knock on wood. A huge factor too is spool up and max tq/boost timing tuning.. i am currently on 3 deg at 5k rpm @320 load.and 6 deg at 5500rpm 320 load steady going up to 19deg @7500. .. you want to have low timing at peak tq /boost in the high load cells..timing should be set at between 2-6 deg in the max boost/peak tq range at high load cells is ideal. too much timing at peak boost/tq and you will go thru many a HG .

 

I would check that radiator again.

 

quick update: mine was absolutely a blown head gasket. both head and block warped (from the P.O. I assume, it's never overheated when I had it) out about .015" which is quite significant. They warped the same direction, however, instead of away from each other masking my symptoms pretty severely.

Just a run down of symptoms:
Pushing coolant, but only on long drives
Perfect compression 155-155-155-155 (Mitsu FSM for the car states 145 as normal for a IX)
No mixing of coolant/oil or vice versa
No significant loss of power that I could notice.
Never overheated, under boost or otherwise (as long as coolant kept up to proper level)
Minor coolant consumption, but mostly just pushing it out of the res.

Basically, the symptoms you might expect from a bad rad cap, except mine was a blown head gasket (that was actually quite severely warped.

Food for thought--- thanks to English Racing for taking on the work of doing the job.