5thgencivic

When you are boosting alot. I just noticed last night my temp gauge would jump from half almost up to the red then back down again. Here I've been boosting for a while now and I just look at the temp gauge after making some hard runs My car will pull, stop pulling a little, pull, stop pulling when it's hot. Can actually hear the turbo spool, then let off a little, spool, let off. After I make a few passes and shut the car down it starts pretty hard too. This happen to any of you? My setup is a Greddy kit with greddy fmic on a sohc.

scttydb411

my temp never makes too great a change (stock gauge though) it goes up a little when running it hard, but it never gets above or even at half way. however i have all new coolant too. my fan just seems to kick on a little more than before. is your car consuming any coolant?

turbo Si

I was some what discussing this topic earlier in my thread today.
https://honda-tech.com/zerothread?id=516264
My temp guage doesn't budge under boost. It actualy begins to climb only when the car is at a stand still. Your fisrt step should be to check the coolant, or radiator for leaks. Also let your car sit and see if the fan is even working!

5thgencivic

yea, it drinks coolant, could also be because it overflows out of the reservoir(headgasket maybe but compression checked out fine). A friend said his temp gauge will jump around like that, so I dunno. Have to keep an eye on it though I guess.

alpha

Time for a leak down test.

Tomek

I remember you posting in my thread a few days ago saying your temps never climbed too high. That was exactly my situation, then my 3rd day into boosting my temps began to climb very high but the reservior was overflowing since day 1 of boosting. Its probably a small leak in the headgasket that is enough to form small air bubbles inside the engine....similar to what I think I have(I'll know when I pull the head once I get all my parts) A compression test wont always show a leaky head gasket.
Does your car smoke at all on startup or when you boost?? I get a small puff of white smoke when I start it cold and a friend driving behind told me he noticed a minimal amount of white smoke comming out when I was boosting.

631 Teggy

could be your water pump...

Quick 200k Mile Motor

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 5thgencivic &raquo;</TD></TR><TR><TD CLASS="quote">My car will pull, stop pulling a little, pull, stop pulling when it's hot. Can actually hear the turbo spool, then let off a little, spool, let off. After I make a few passes and shut the car down it starts pretty hard too.</TD></TR></TABLE>

How hot? you never said. Hot like past the half mark on the temp gauge?
Past the half mark is when you'll start to see decrease in performance.

I suspect its getting tremendous heat soak.
The car must be moving, or fan must be on.
The temp can climb because of the fan not turning on.
If I were you I would keep the motor idling for a little
just for coolant to circulate around, instead of shutting it down right after a pass.

It's summer.
Use a bottle of "Water wetter".

5thgencivic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I just noticed last night my temp gauge would jump from half almost up to the red then back down again.</TD></TR></TABLE>
A slight decrease in performance. Just now noticed the temp gauge that high, so it could have been happening for a little while. Hmmm, maybe I should go ahead and replace the head gasket and water pump...

scttydb411

do the timing belt at the same time. good luck.

SMUDGE

If the HG is starting to go, boost may pressurize the cooling system and force coolant out of the rad and into the overflow tank.
That's what happened to mine.It only happened when i boosted hard and not when i drove really easy.