Lower Radiator Hose - Stays Cool

XpL0d3r

I had a Civic once.
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Replaced T-stat, ECT sensor, Fan Switch Temp sensor, and bled the coolant.

Fan seems to always be on (at least when car is warm), and the lower hose is straight up cold. Any ideas? Was thinking clog in the radiator (Mishimoto radiator), and HOPING it's not the water pump, lol.

OH, and I have heat.. which is why I'm confused and posting this.

Thanks!
 
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TigBitties

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i have a d16 and my lower hose is always cold i think, but upper is hot
 


Mishimoto

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Are you overheating? If so, I assume you are only overheating at idle since you mention the fans coming on?

If you are overheating, and the upper radiator is hot while the lower hose is cold, the thermostat could be stuck. I would look at that first in my opinion.

Where did you get the replacement thermostat from? Have you tested it to verify it is opening and closing as it should? I have seen numerous Tstats fail right out of the box. If the Tstat is working properly, is the radiator cap holding pressure? The last option would be remove the radiator and flush it out with a garden hose and check the flow. If the water begins to start backing out of the same inlet you are putting water in, that is a sure sign there is any issue with the radiator.

How long have you owned the radiator? It is rare to see a radiator just become clogged out of nowhere to be honest. Also, check out our guide on overheating. There may be something on there that I missed here.

http://www.mishimoto.com/how-to-guides-overheating-troubleshooting-guide.html
 

TigBitties

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well thats about the best answer i would think you can get
 


XpL0d3r

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Haha truth.

It is not overheating at all. I've even sat there car fully warm for about 10 minutes, and no overheating what-so-ever. Radiator is pretty new, from around August or so, and has no more than 1000 miles on it.

T-stat is from Advance Auto, so I'll remove and test at some point. As for the cap I believe so, but not 100% positive. We never let the car run after filling the coolant, so I'm going to top it off and see what happens.

Thanks for the link and info!
 

TigBitties

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i think your fine then. my lower hose is pretty cool and my car never over heats. i beat on it and it doesnt even get half way up the gauge
 

Mishimoto

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How's the heat in the car? I am referring to climate control.

If that blows hot, it sounds like everything is fine with the car.
 

XpL0d3r

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How's the heat in the car? I am referring to climate control.

If that blows hot, it sounds like everything is fine with the car.
Heat in the car is fine, so hopefully all is well. I highly don't think it's a problem with the radiator (I love it btw), and it's not any sensors since they're brand new. T-stat maybe, but heat is fine inside the car.

Thanks for the help!
 

Mishimoto

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You should be fine. I have 99 Civic and it seems like it takes forever to heat up. I'll sit in a parking lot idling for at least 30 minutes before the fan kicks on.
 

XpL0d3r

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Made a nice 2 hour drive twice this weekend and checked the hose both times upon arrival to destination... lower hose was actually warm, and the fan was on and kicking. No overheating problems or heat problems whatsoever. All should be fine, I hope.

Thanks!
 

RonJ

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Cold Massachusetts temperatures this time of year probably explain your thermostat rarely opening.
 

XpL0d3r

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Cold Massachusetts temperatures this time of year probably explain your thermostat rarely opening.
Fall months in Houston also probably explain RonJ 's rare appearances this time of year too :lol:
 


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