What could be the cause of my hatch to be overheating. Its fine for the first 10 minutes or so of driving, then the meter jumps to H really fast. On the highway if goes up then cools down then up and down again. I had my heater on and when it blows hot its fine....then when the meter goes HOT its blows cold. Its does this on and off. I am thinking that the thermostat is not opening.

Any advice will be helpful or thoughts of what may be wrong will help.

Thanks -P

 

any suggestions??

 

thermostat...

 

make sure ur resovouir tank is not over filled, it has happened to me.. but do check ur theromstat!

 

I would say thermostat or water pump. good luck.

 

your rad could be clogged do a flush replace the thermostat and see what that does for you. if thats not the prob, i have herd of people having the same prob when the water pump was about to die. is could also be the sending unit to your gauge. just a thought

good luck

btw the engine stand is workin nicely..

Blaze

 

in this order

flush/refill radiator
inspect all hoses
thermostat
and then try replacing radiator cap
lastly check fan motors.

 

I normaly start with the cheapest thing and work through according to price.

Only cause im broke as heck, hehe.

 

Have you recently changed the fluid? Sounds like you have air in the cooling system. The up and down of the temp gauge hints to air being trapped. Drain the coolant and when refilling make sure to use the bleed screw on the upper rad hose. Let all the bubbles escape before tightening the screw to 8 ft-lbs. Also just for piece of mind change out the t stat while there is no coolant in the system. HTH

 

thanks for the help everyone.....I will be doing all the thing suggested.
The coolant has been replaced recent, but i did not flush the system. I recently changed pistons rings and swapped on a nothing Si (a6) head, due to the old one having a broken valve. Once the work was complete, new coolant was put into the system. The car runs fine for a while then does the things I mentioned. I'd open the cap to let pressure out and I do notice that it bubbles up ( like spit air bubbles).

I will keep this update as maybe someone else may have the same problem later.
Thanks to ALL!

 

did you bleed the air out of the coolant system?

 

yes, i did bleed the coolant while filling.....

 

I'm having the exact same problems with my JDM SiR over here at the mo!

I'm pretty sure its the water pump, i've checked all the usual suspects (water, hoses, rad cap, radiator etc), its not showing signs of full on headgasket failure!

The impeler (fan), in the water pump can corrode, and once the engine is put under extreme load....the corroded fan cant pump the water round fast enough!

Mine only gets hot when booting it, but normal driving and idling speeds, its fine!

Its in the workshop at the mo, so i'll let u know how i get on!

Dan!!

 

heres a pic of a knackered water pump (of a Mk2 CRX VT)

 

check ur fan. if the fan doesnt wor it will get hot very fast and while driving it will cool down a bit but then when u stop again it will heat up real fast.

 

I had the very same problems with my B16A in my CRX. The water pump was pretty much gone.

 

Fan blows and wroks fine......

 

my fans work fine aswell...the rad fan kicks in as normal, and the aircon fan comes on when asked.

theres been about 9-10 of these pumps gone on our crx club cars over here, all with the same symptons...i bet its the water pump!!

Dan!!

 

Me LS is doing the same thing. Both fans run fine. The upper coolant hose is hot, but the lower seems cool? If the thermostat was going out the upper coolant hose would be cool, too, right? Does the water pump make noise before it goes out. My car make a grinding noise in that area, though I just ASSumed it was the alt about to go out. This car never overheated before and it has plenty of coolant, haven't had to put any in since I bought it several months ago. BTW, oil seems to be fine. Any help please.