Coolant Disappearing

[Gords_zenith]

Originally Posted by 448hpsti

if you smell it, there is a problem!

That's what I thought ant mentioned to my dealer, however it's only a faint smell when first start the car up or turn the car on, so the fan hvac fan is blowing. But like I posted, I'm looking for instructions to get to the heater core to inspect for myself. My dealer has also refused the TSB for the window switches so....to get them to look into something is a huge hassle.

[Suberman]

Originally Posted by Gords_zenith

I'm still having coolant issues and coolant smelling hvac when I first start it up. Spoke with the dealer about paying for a pressure test and if they find anything that will warranty it. Still haven't back from them and this is the third time I've mentioned it. I also have pictures documenting the reservoir tank level dropping. And they still won't do anything about it. Does anyone have any information on how to properly do a pressure test yourself-I'm very mecanically inclined so I just need the actual procedure for this car as well as any documentation of getting to the heater core? I have the sport-tech (limited-I.e auto climate control). I'm also getting an oily residue on my windshield fairly quickly which maybe implies a heater core, but I'm not sure. Any ideas?

Oily residue should smell faintly of coolant if heater core is seeping. Most if not all new cars get vinyl vapour deposits on their new windshields. Use a paper towel to wipe the suspected film off and give it the old nose test. Coolant has a distinctive odour, different for different types though. Does this engine use green or pink?

[fstlane]

Originally Posted by Texaz Boy

I've had my car for two months and it has 3600 miles on it. I noticed the coolant was not completely full. And I just checked it about an hour ago and its at the low mark. I'll will check in the morning after its been sitting for 12 hours. Any thoughts as to why this is happening? When I've gotten off the highway I can smell coolant when I stop at a light. Anyone have any thoughts?

I'm at 4100 miles and my level when cool also read at the low mark. Adding 1 cup of diltilled water brought it up to the full mark when the engine is up to operating temperature. I would consider this normal and you shouldn't worry especially considering your environment.

[White64Goat]

Pressure test it. Most pressure testers have a pressure gauge mounted to the pump handle. Pump up system to operating pressure and watch gauge for 15-30 minutes. It should not drop. If it does, you have a leak somewhere. Your dealer should be able to do this and if they won't, contact Subaru.

[Gords_zenith]

Originally Posted by Suberman

Oily residue should smell faintly of coolant if heater core is seeping. Most if not all new cars get vinyl vapour deposits on their new windshields. Use a paper towel to wipe the suspected film off and give it the old nose test. Coolant has a distinctive odour, different for different types though. Does this engine use green or pink?

Yes I know about the vinyl residue but I'm now at 35000 km and that should be long gone. This engine uses subaru's super coolant which is blue.

[Gords_zenith]

Originally Posted by White64Goat

Pressure test it. Most pressure testers have a pressure gauge mounted to the pump handle. Pump up system to operating pressure and watch gauge for 15-30 minutes. It should not drop. If it does, you have a leak somewhere. Your dealer should be able to do this and if they won't, contact Subaru.

Thanks. But is there anything specific to testing the heater core like needing to leave it to its heat setting? Or anything like that as I used to have a ranger that when it selected to off there was a valve that would close preventing the coolant from going to the heater core thus eliminating that circuit. Is there a test pressure limit? I know the stock system runs at roughly 16 psi, but don't want to exceed any design limit rupturing something, you know?

[White64Goat]

If there is a PSI listed on the cap, that's your limit. Usually around 15 lbs.

[Nightbringer]

Don't have anything useful to add to this thread unfortunately, other than mine is slowly losing coolant as well. First noticed it at 8000 miles, and has been increasing in quantity missing since. I'm perplexed on the "evap is normal" concept. On all my previous cars I've never had to top them off, so anything that evaporated was negligible. Only time I've had to every oil change was a heater core leak or a head gasket. Not trying to be rude, just curious if someone could give me a layman's explanation. I understand it's a vented tank, I've just never had experience with this quantity of evaporation taking place.

[Turkish]

@civicdrivr I may have missed it (I just found this thread), but did the repair affect your original issue in this thread?

On a side note, Toyota seems to want to disown the frs based on their desire to take care of their customers. At least at the dealership level. Also, it sounds to me like they never had a FE involved if he was never available.

Sent from my SCH-I535 using Tapatalk 4

[fstlane]

Originally Posted by Nightbringer

Don't have anything useful to add to this thread unfortunately, other than mine is slowly losing coolant as well. First noticed it at 8000 miles, and has been increasing in quantity missing since. I'm perplexed on the "evap is normal" concept. On all my previous cars I've never had to top them off, so anything that evaporated was negligible. Only time I've had to every oil change was a heater core leak or a head gasket. Not trying to be rude, just curious if someone could give me a layman's explanation. I understand it's a vented tank, I've just never had experience with this quantity of evaporation taking place.

I'm not an expert but here's my take on it. The majority of the cooling system is sealed however the expansion tank is not. It has a simply plastic snap on cap that is not completely sealed. The coolant is a mixture of around 50% water which can evaporate from the expansion tank especially with 200 degree coolant moving through it. Add high underhood temperatures and summer months on top of it and it's likely just evaporating from the expansion tank. The tank is actually pretty small as well so what appears to be a lot is probably just a few ounces. I could be way off but I hope it's nothing serious as my previous vehicles didn't lose much either.

[Books]

Interesting thread. I noticed a few weeks ago that my coolant reservoir was totally empty in a span of 4k miles! (I had it topped off at my last oil change) I didn't check the radiator cap but I will do so next time. It has been very hot in the past few months so I'm hoping that was it.

Sent from my Galaxy Nexus

[Suberman]

Originally Posted by fstlane

I'm not an expert but here's my take on it. The majority of the cooling system is sealed however the expansion tank is not. It has a simply plastic snap on cap that is not completely sealed. The coolant is a mixture of around 50% water which can evaporate from the expansion tank especially with 200 degree coolant moving through it. Add high underhood temperatures and summer months on top of it and it's likely just evaporating from the expansion tank. The tank is actually pretty small as well so what appears to be a lot is probably just a few ounces. I could be way off but I hope it's nothing serious as my previous vehicles didn't lose much either.

Both water and antifreeze can evaporate. There is a fair bit of air circulation through that expansion bottle as it is not sealed and pressurized as for European systems. You will lose a tiny amount of coolant mix every heat cycle as a result of this air pumping in and out as the coolant in the system expands and contracts. I find it very odd that Japanese cars still use radiator caps.

Actually, the only manufacturing defect on my 1998 Mazda Protege was a defective radiator cap, come to think of it. The only warranty claim I made. The dealer kept replacing the block heater because that's where the coolant blew out when the rad cap failed to relieve expansion into that bottle. The reverse effect: a rad cap with insufficient spring pressure could cause a loss of coolant.

European systems pressurize to around 21 psi and are designed not to breathe up to that pressure. They have enough head room to allow only some air out at higher than designed pressures, breathing air back in when the system cools. The expansion bottle systems have to "breathe" coolant out and back in.

[civicdrivr]

Originally Posted by Turkish

@civicdrivr I may have missed it (I just found this thread), but did the repair affect your original issue in this thread?

On a side note, Toyota seems to want to disown the frs based on their desire to take care of their customers. At least at the dealership level. Also, it sounds to me like they never had a FE involved if he was never available.

Sent from my SCH-I535 using Tapatalk 4

Not entirely. I'm still losing coolant, but at a much slower rate. I am now starting to believe that it did have something to do with evaporation. My other car doesn't have a sealed tank either, and I've never had to add coolant in the 5years/110k miles Ive put on it, but it doesn't run as hot as the FR-S either. The one thing that makes me somewhat nervous is that this wasn't a very hot summer, so Im curious to see how the coolant levels fare next summer.

I picked up the Robispec rad/oil cooler two months ago. I'm still waiting for the sandwich plate and lines, but I'm hoping once I install it the coolant loss would slow or (preferably) stop altogether.

[FRSBRZGT86FAN]

Originally Posted by civicdrivr

Not entirely. I'm still losing coolant, but at a much slower rate. I am now starting to believe that it did have something to do with evaporation. My other car doesn't have a sealed tank either, and I've never had to add coolant in the 5years/110k miles Ive put on it, but it doesn't run as hot as the FR-S either. The one thing that makes me somewhat nervous is that this wasn't a very hot summer, so Im curious to see how the coolant levels fare next summer.

I picked up the Robispec rad/oil cooler two months ago. I'm still waiting for the sandwich plate and lines, but I'm hoping once I install it the coolant loss would slow or (preferably) stop altogether.

Maybe its time to invest in a better radiator before next summer? I mean these high compression FA20s run hot but I heard mishimoto and Koyo make good radiators that are actually better than stock.