Hey,
It's me again. I've got a 91 Civic HB Standard and I just put a 41 wet shot of NX nitrous on it. The first time i took it out to the track when I got there (sprayin nitrous a few times on the way to the track) my coolant reservoir was boiling and overflowed! The temp gauge in my car never moved. I emptied some of the extra coolant in the reservoir out and ran the car (5 runs, 15.04 best time) on the track and throughout the night it kept boiling in the reservoir. The temp gauge still never moved at all. I drove the car for a week with no problems and no boiling... not once did the temp gauge go above normal. I took the car to the track again this time I drained my radiator and added new coolant (didn't drain block) and some Redline Water Wetter. Again on the way to the track I sprayed a few times and when I got there the reservoir was boiling and overflowing! I think I lost a lot of coolant throughout the night this time. The car was fine the whole night at the track and on the way home the temp gauge went almost to the red! I had coolant running everywhere. Why is this? It seems to only do this when I use nitrous. Could my radiator cap just be old? It is still the stock one from 91! I don't think the head gasket is blow cuz there isn't any coolant in the oil, I don't see any leaks from around the head/block, and the power isn't affected. Plus the car doesn't do this under normal/hard driving... only when I spray.
I know this was a lot of info, but please any help would be great. Could my water pump possibly be going? Thanks.
Later, Davey

 

looks like you have a weak / blown head gasket

 

Thanks for the help...
can anyone else back this up?
why is it only when I'm on the bottle, daily driving it doesn't boil like this...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ahknodd &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the help...
can anyone else back this up?
why is it only when I'm on the bottle, daily driving it doesn't boil like this...</TD></TR></TABLE>
basically,when on NOS,there is more pressure in the cylinders-the old headgasket can't handle it.

 

Alright, so I need a new head gasket... but will an aftermarket high pressure radiator cap help in the mean time? Also what are the benefits/draw backs of these caps? What are the best ones to get? Thanks again.
Lates, Davey

 

If it wasn't overheating, but still boiling in the overflow.....gotta be headgasket.

Just roll it over like the others and start again

 

hey man,
We don't need any of that crap on here... so what I've had some miss haps in the past but no need to say **** like that.

Davey

 

Sorry Davey....just noticed a pattern.

*e-hug*

 

Yeah and it's a pretty shitty pattern... Young and Dumb, just pisses me off. It's all good though
Lates Davey

 

i dunno. my reservoir has been bubbling a bit lately too. i actually require refilling just the reservoir in order to stop it form happening, until it all steams out again.

im not certain its not the head gasket, but i see no reason why it would be. im not losing fluid in the radiator. im certainly not blowing white smoke out the tail. so that tells me theres no issue with a blown head gasket.

i dont race nor over rev the engine, rarey go over 6k rpm.

my temp guage never moves beyond normal. however, we all know the stock temp guage has a pretty wide spectrum for being "normal".

i think its just needing a new radiator cap. they do go bad, lose sealing and therefore pressure and lower the boiling point. so i got a new radiator cap this week. i honestly havent bothered to put it on. im gonna flush the system first. hopefully that'll fix it and everything is a-ok.

 

it could be the cap it could also be your thermostat, they are both very cheap so iw ould start with this. try a compression test and/or a leak down test they'll tell you a little about whats going on worst case it is the head gasket hopefully its not

 

I'm posting this incase anyone has this same problem...
My coolant had been boiling in my reservoir and was actually pushed out through it while I was driving. My car overheated a few times because it was very low on coolant since a lot had escaped. I had installed a nitrous kit (NX 50 shot) and like they always say, "nitrous doesn't cause problems, it acentuates problems that are already there". So since I started using nitrous I was having this coolant problem. What was happening was the nitrous was making a lot more pressure in my cylinders and I must have had a tiny leak between one of my cylinders and the coolant passage beside it (not into the oil passage though). When I would spray nitrous the pressure in my cylinder would escape into my coolant passage which would push my coolant out my radiator cap and into my reservoir and it would over flow. It would boil because your coolant in your motor is often above the boiling point of water (212 degrees F), but it can't boil cuz your radiator cap keeps the coolant compressed as water and it can't evaporate into the gas state or steam. But the pressure in my cylinder when on nitrous which passed into my coolant system was more than my radiator cap could handle (which is like 14 psi I think) and so my coolant would escape. I didn't know what was causing this so I searched to find out. And no one could answer with any kind of definate resolution.
One morning I went to start my car for work and it would try to turn over, but it seemed like it would get stuck. It wasn't seized, but it couldn't turn over. What it was was my coolant had leaked into my #2 cylinder and it happened to be on the compression stroke (all valves were closed, compressing the air/gas to be burned). Since all the valves were closed, there was no place for the coolant to go and it stopped my motor from turning over. So the end result was a blown head gasket and some coolant in my cylinder.
No biggy, bring on that mini me head swap!
Hope this helps someone.
Later, Davey

 

thats exactly what happened when my hg **** the bed