Coolant Temp under Boost...
 

I've been noticing something new lately...

My car runs nicely at 200' all the time regardless of outside temp, traffic, and hot days etc.. But lately under boost the coolant temp maxes out.

It is at say 205'F then as soon as I make a pull it will taper up to 260 then the second I get off the gas it instaly goes back down to 200. If I stay out of boost it will stay around 200, it's only when I boost that it skyrockets.

I change/checked both my oil and coolant and neither have any signs of mixing, the car doesn't show any signs of overheating or anything well boosting, and i don't seem to be loosing coolant. But it does seem to be running hotter, and doesn't like to idle too well imeditly after.

My only few guesses is that the head is lifting, which i doubt since I'm running ARP studs well tq'd and a cometic headgasket, or a sleeve is cracked but also unlikely since there GE godzilla sleeves and compression is fine, and I have no mixing of oil/coolant.

Just seems weird, that the coolant could get heated and cooled so rapidly, going from 200-260 in 1.5 seconds then 260-200 in like 1-2 seconds.

I'm running a Koyo dual core alumin radiator, and a FAL fan which I have never had problems with before..

Any help, ideas. or experiences would be appreciated, thanks... https://honda-tech.com/forums/images/smilies/emwink.gif https://honda-tech.com/forums/images/smilies/emthup.gif

Re: Coolant Temp under Boost... (Alstare)
 

what are you running in the rad? also how close is your DP to the Rad? that might make a diff

Re: Coolant Temp under Boost... (Alstare)
 

I dont think Ive seen my coolant temp go past 210*. 260 is way high. Id look more towards air bubbles or or possibly bad thermostat. Is your fan even coming on? Is it blowing in the right direction? Does it over heat when your driving or after you slow down/stop?

Re: Coolant Temp under Boost... (Muckman)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">I dont think Ive seen my coolant temp go past 210*. 260 is way high. Id look more towards air bubbles or or possibly bad thermostat. Is your fan even coming on? Is it blowing in the right direction? Does it over heat when your driving or after you slow down/stop?</TD></TR></TABLE>

https://honda-tech.com/forums/images/smilies/emthup.gif everything he said.

Re: Coolant Temp under Boost... (DaX)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I dont think Ive seen my coolant temp go past 210*. 260 is way high. Id look more towards air bubbles or or possibly bad thermostat. Is your fan even coming on? Is it blowing in the right direction? Does it over heat when your driving or after you slow down/stop?
</TD></TR></TABLE>

Yeah untill lately I haven't ever seen my temps go that high either.

But now that you mention it I did recently convert to an open dump for my downpipe stright down right now well I save up money for a nice new 3". :hammer" But i made the piping go straight down lower then the oil pan so I figured well driving the exhaust would blow under the car, maybe it's getting trapped in the engine bay and heating everything up.

So maybe that's not helping, I have flushed my coolant a few times and I'm sure it's not air bubbles, and I'm gonna try a new thermostat this week.

My fan is definitly comming on since I have it hardwired into my EMS. I have it comming on after 180'F and I have varified it is comming on and in the correct direction.

It doesn't overheat at all well normal driving, just logging I notice my coolant temps sky rocket under boost, and then under normal driving there fine. And I have noticed some overflow from the resivoir afterwards, and my coolant a bit lower.

Re: Coolant Temp under Boost... (Alstare)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Alstare &raquo;</TD></TR><TR><TD CLASS="quote">
And I have noticed some overflow from the resivoir afterwards, and my coolant a bit lower. </TD></TR></TABLE>

Now we're starting to sound like a headgasket or head lifting under boost.

Re: Coolant Temp under Boost... (DaX)
 

wouldnt it be really obvious though if the head was lifting?

Re: Coolant Temp under Boost... (DaX)
 

How about checking the condition of the Rad Cap???

That would explain the overflow also.

Re: Coolant Temp under Boost... (CRX T-Si)
 

Just some experience from overheating civics:

-Thermoswitch? but it seems your ems kicks the fan on
-Radiator? how old is your radiator?
-Radiator cap? doesn't hurt to try
-Thermostat?
-Waterpump failure?

Well, hope you get to the root of this. Good luck!

Re: Coolant Temp under Boost... (95stangkillah)
 

Thanks guys... https://honda-tech.com/forums/images/smilies/emwink.gif https://honda-tech.com/forums/images/smilies/emthup.gif

I'm gonna get the whole system flushed, new rad cap, thermostat, and check the water pump. Hopefully that helps, but if not, I guess I'll yank the cam's and try and re TQ the ARP's. https://honda-tech.com/forums/images/smilies/emwink.gif https://honda-tech.com/forums/images/smilies/emthup.gif

I really don't feel like the changing a HG...lol

Re: Coolant Temp under Boost... (Alstare)
 

definately sounds like head lifting to me. Is your overflow bottle filling up?

Re: Coolant Temp under Boost... (boostismycrack)
 

Seems to go up and down as usual, but there is some indication that it has overflowed a bit recently.

Re: Coolant Temp under Boost... (Alstare)
 

Have you identified your problem yet? I just devleoped the same problem that you are having. Car starts to overheat then comes down slowly if i stay out of boost or turn the heat on. teh last time it started to overheat i changed the radiator, which helped it go away for a while. recently i tried changing the thermoswitch too, because for some reason, my fal fan is not coming on. I checked the fuse for the cooling fan too. There is no mixing of oil and coolant and it doesn't seem like I'm losing coolant either. very frustratind indeed. any help would be apreciated.

Re: Coolant Temp under Boost... (95stangkillah)
 

I found some really old logs of mine from back in march and it appears it was maxingout under boost even back then... So apperintly this isn't a new problem just something I finally noticed. https://honda-tech.com/forums/images...s/emthdown.gif

I re-tq the headstuds, they were fine. swaped out the thermostat, flushed the cooling system, got a new rad cap and tried some water wetter and still no better.

Although removing the thermostat did drop my normal driving temps from 200 to 180 and it stays there nicely. But I plan to replace the thermostat with a new one as soon as I findout where to get one for a JDM h22, which is not the same size at the US ones... http://images.honda-tech.com/set1//smile/emcrook.gif

I plan to swap in another coolant temp sensor this week too.

I have my wg dumping open into the engine bay right now so that is not helping either, so I plan to route it out and under this week to help.

Also I think I may take off my front bumper and make some runs to see if maybe I'm not getting enough airflow to the rad with the FMIC in the way...

Re: Coolant Temp under Boost... (itr206)
 

Heat wrap the downpipe, add another fan on the other side of your radiator with a switch, and make it blow air through the rad. It should fix your problem. Good luck https://honda-tech.com/forums/images/smilies/emthup.gif