OK to Re-use Coolant?

I was just thinking. I changed my coolant about 2 months ago, but I didn't install a new thermostat. I'll probably put on my car 20,000 miles a year, so I don't think my OEM thermostat will get through the winter safely. If I change the thermostat, do you guys think it would be fine if I re-use this 2 month old coolant?

Crucial Racing has a 160 degree thermostat that they sell. What are it's advantages and disadvantages? Engines like to run hot, right? Increased cooling to motor = less efficiency, you think?

 

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by kickin_81

I'll probably put on my car 20,000 miles a year, so I don't think my OEM thermostat will get through the winter safely.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Seems to me that a thermostat is something you replace when it is kaput, but it is not a preventative maintenance item. That is, you don't replace it every 30/60,000 miles or whatever just for the heck of it.

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Crucial Racing has a 160 degree thermostat that they sell. What are it's advantages and disadvantages? Engines like to run hot, right? Increased cooling to motor = less efficiency, you think?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

That sounds essentially backwards to me. With forced induction, anything that can be done to provide extra cooling to the cylinders should help lower the risk of detonation or pre-ignition. Go back through the famous thread on nasioc talking about all the people who have blown the #4 cylinder. One of the better theories for this is that there are fewer cooling passages in the block back there...combined with the fact that the intake runner flows more air to that cylinder...combined with too much ignition advance and/or boost...*knock* *knock* *BOOM*

 

I'm scared...

Thanks for the advice, Joel. I'll probably save up for one just in case so I won't have to wait a week for it to get shipped when mine does need to be replaced.

 

I wouldn't be scared, like you said elsewhere, yours is tuned for 91 octane so it's probably very conservative with advance.

Anyway, I would get a second opinion besides mine.

 

Are you scared that the thermostat will not make it? I never reuse coolent but I don't see the issue with the thermostat. Most of my cars usualy make 80-100k miles before replacing the thermostat. Except for this crapy minivan that I had, but that was a design flaw.

 

Fong,

If your that scared and dont mind chaning your thermostat every summer, I would recomment drilling two little holes on the thermostat to allow more flow. But make sure you change it for the winter.

C

 

That's what I'm talking about! I have wondered if a lower temp thermostat, much less, a free-flowing one would provide negative results as well as good one. I thought to myself on how the winter would affect a cooler running system. Coolant doesn't freeze easily, but if it ever does (my experience in fact), I would not want it to freeze in the block or the water pump. I cruise at least 95% of the time on the street so I suppose an OEM thermostat will provide the most year-round safety. Thanks for the eye-opener, guys!

 

I read somewhere that if you add more water instead of mixing 50/50. The effect of that will actually lower the engine temperature, the only drawback is that water evaporates quicker so your going to have to monitor the fluid level. Also Redline has a great product called Water Wetter. I'm sure there are other brands out there too that works great.

 

Yes, C. Those graphs of cooling temps of water(distilled) vs coolant are actually on Redline's website. I have invested in Redline's water wetter and genuine Subaru coolant for all my engine cooling needs. I use them because the hardcore racers use them.

 

After 20k and you are doing the thermostat I would replace the coolant. The thermostat is indeed a routine maitanance item. I would (and usually do) change it once a year. I generally change the coolant with the seasons.

Routine maintanace is the KEY to how long your engine will last.

 

Yeah, the thermostat is something that's not listed as routine maintence from Subaru. You could call it "preventative maintence." My motor currently has 60K miles on it, so I would probably do it before the winter. Just to be safe.