Blowing Anitfreeze, but no overheat.

DawgTool · #1 04-08-2007, 08:18 PM

Hi All,

I have a strange issue with my SVX.
Background:
I recently replaced the stock radiator with a PWR aluminum one. The stock radiator had cracked (hair line fracture). I have never had any over heating problems. No oil in the antifreeze, no antifreeze in the oil.

Issues:
Heater blows cool when at a stop, when the car is moving air is hot again. Temp is set to 75 degrees.
PWR radiator is blowing antifreeze when at normal running temps. Antifreeze is coming from the cap, which appears to be in new condition (it is new, so it should be). Smell seems metallic in addition to the normal antifreeze smell.

Info:
Engine is not burning oil, running synthetic oil.
Over flow does not appear to be clogged, but its possible.
Car does not over heat, even if I run it very hard. Usually this just causes the pressure to build up and more antifreeze is blown.
The head gaskets were replaced about 2 years ago, the water pump was replaces 6 years ago.
I'm ruling out the water pump, thermostat, and head gaskets because the car does not over heat, blow smoke and there is no sign of mixed fluids.

Any Ideas?

Thanks,
DawgTool (Subaru SVX Sport)

SA SVX · #2 04-08-2007, 09:02 PM

What ratio of antifreeze to water did you or they use? If its to high a mix it could cause this type of a problem. Also DONT rule out the thermostat, they will fail intermittently before they finally fail.

ensteele · #3 04-08-2007, 09:36 PM

The PWR radiators had some issues with the caps. You might get a new cap and try it to see if that cures your problem. Did you have a clearance problem with the cap and your hood?

Trevor · #4 04-09-2007, 04:26 AM

Quote:

Originally Posted by DawgTool

Hi All,

I recently replaced the stock radiator with a PWR aluminum one. The stock radiator had cracked (hair line fracture). I have never had any over heating problems. No oil in the antifreeze, no antifreeze in the oil.

DawgTool (Subaru SVX Sport)

In N.Z. a few days ago, a fix for the same fault cost me N.Z.$20,00, say US$17.00.

DawgTool · #5 04-09-2007, 06:34 AM

The antifreeze mix is about 1:4 water/antifreeze, so that could be an issue. I ran a radiator flush (with the old radiator) before installing the PWR, hopefully that cleared any junk that was sitting in the lines. After draining, the coolant still looked really clean.

You may be right about the cap, I will contact PWR and see if they can send me a new one.

I did have some clearance issues at first, but after forcing (read pushed and hammered) the radiator to settle into the mounts, no issues. The bushings tend to get really dirty on the bottom mounts, so make sure they are cleaned/replaced before installing. Also I positioned the top mounts as far back (towards the rear of the car) as I could. That gives the radiator a little bit of an angle, so it does not sit as high.

Still not convinced about the thermostat, but I will replace that as well, just in case. On most of my other Subarus, if the thermostat was going bad, the car would tell you really quick, aka: over heating. My SVX isn't over heating at all, in fact to runs cooler then it did with the stock radiator.

Any suggestions about the cool air when the heater is on? It only happens when I'm at idle, as soon as I start rolling, hot air starts again.

Thanks for the replies.
-- DawgTool (Subaru SVX Sport)

Joe 90 · #6 04-09-2007, 07:43 AM

Hi,

I had a similar issue a few years ago.... Found out the anti-freeze/water mixture was wrong.

If you have 4 anti-freeze for 1 water, I believe it's too "rich". a 50/50 mixture is usually recomended.

I suggest you try correcting the mixture first before spending more money.

Good luck!

kewilo · #7 04-09-2007, 01:00 PM

Hey Dawgtool,

I'm am currently having pretty much the exact same issues with my new PWR rad install. The same possibilities come up such as the thermostat, water pump, leaking head gasket... I use premixed coolant so that shouldn't be the problem.

Have you found the cause of the problem. If so, please let me know as i just want to get my svx back on the road.

My thought is that the install is correct but whatever caused my stock rad to blow is causing the same issues in the new one.

Thanks

kewilo · #8 04-09-2007, 01:03 PM

just realized, you just posted yesterday.

kewilo · #9 04-09-2007, 01:04 PM

Quote:

Originally Posted by Trevor

In N.Z. a few days ago, a fix for the same fault cost me N.Z.$20,00, say US$17.00.

So trevor, do you know what was causing the problem?

Trevor · #10 04-10-2007, 01:26 AM

Quote:

Originally Posted by kewilo

So trevor, do you know what was causing the problem?

Sorry for the confusion. I was referring to your stock radiator replacement. Refer my post regarding radiator repairs.

You state that anti freeze is coming from the radiator cap. Surely this must mean that either the outer main gasket/washer, or the sprung seal which holds the required pressure, is leaking. Probably the former, as the pressure seal exits via a drain tube.

It is also interesting that you mention that the engine is running cooler. This could indicate lower than normal pressure and also ties in. Check for a damaged filler neck, a dent on the seal face caused in transit or whatever, could be causing the gasket/washer to leak.

TomsSVX · #11 04-10-2007, 03:07 PM

the problem is the cap necks that PWR uses on their radiators... The caps do not seal very well. ALSO... the fact that your hood is probobly hitting th cap on one side and cocking it allows anti-freeze to leak.... AND you should be running a 50/50 mix of anitfreeze to water... too rich and too lean of a mixture causes the boiling points to change and severly effect the cooling and expansion capabilities of the fluid. You won't overheat until the coolant level goes down far enough to allow it

Tom

themoneypit · #12 11-11-2007, 03:49 PM

Quote:

Originally Posted by ensteele

The PWR radiators had some issues with the caps. You might get a new cap and try it to see if that cures your problem. Did you have a clearance problem with the cap and your hood?

radiator cap is the cause. i installed a pwr in my 92 and had the same problems with coolant leaking around the cap. problem is, the pwrs come with a 16lb cap, ours require 13lbs so the system is building too much pressure. i bet if you look at the top hose its ROCK HARD when hot.

put on your stock cap or buy a 13lb cap from anywhere and you should be good to go. worked on mine.

crazyhorse · #13 11-11-2007, 04:04 PM

Blowing cold air when the heat is on usually means an air bubble in the system. Seeing as you recently replaced the radiator, this could be the culprit. Also, since you've been losing coolant, that could have caused one to form.
Get your radiator cap issue fixed then properly "burp" the system. After that you should be golden.

bugs · #14 11-11-2007, 07:32 PM

In addition to the cap losing pressure it sounds like your thermostat might be stuck open. That could account for it blowing cool (less hot fluid through the heater core because of low rpm) when stopped and warm when driving.

Eric

gsodonis · #15 11-12-2007, 06:17 AM

I have one on the first production PWR rads and mine needed the custom PWR cap to avoid hitting the hood when closed. Neither their original cap that came with the rad, nor the second cap that they sent to fix the problem fit right; it appears that their filler neck groove - the one that the cap rides in - was machine too close to the top sealing surface of the filler neck. The cap would be in the fully locked position, but the cap gasket wouldn't make a tight seal against the upper sealing surface of the filler neck.

That causes two problems. The overflow tank is really an expansioon tank and a critical part of the cooling system. As the coolant warms, it expands. As it expands, it flows into the expansion tank from the bottom via a hose that must be covered by coolant at all times to work properly - that's why you see a min level stamped on the side of the expansion tank. When the engine is off and the coolant starts to cool, it contracts. While contracting, it creates a vacuum which draws coolant from the expansion tank back into the radiator, thus keeping it always full. Without the expansion tank (or without sufficient coolant in that tank), the rad would suck in air into the system rather coolant and as we all know, our SVX's hate air in the coolaing system.

I found that the PWR caps are simply cheap and don't seal well. When running one, my car always smelled like leaking coolant - nothing obvious leaking, but the smell was always there. That was the coolant leaking past the cap and running down the front/rear of the rear where the heat would cook it off.

the fix - Just buy a Stant 13lb cap at Autozone ($6 - get it without the pressure relief lever - it might the hood). If your rad is an early production model, you'll need to hacksaw off one of the cap 'ears' and when you install it, the remaning ear will have to face the engine, not toward the front - that's how I get mine to fit. My smells and leaks went away after that.