Hallo,

i have a strange coolant problem some time ago...
i made the following changes from the stock coolant system:

- new half size radiator but with old radiator cap (reused)

following symphoms:

- stock water temp gauge stays where it is normal, so from this gause (i know its inaccurate) its not overheating
- when i drive everything is normal
- but when i park the car i notice that my fan is on every time, also when it is not very hot outside (aprox. 10-12°C) and it stays on for aprox. 3-4min. when i shut off the engine and reengage the ignition so that the fan could stay on.

- after long (~65-70mph) highway runs i notice some coolant spray over my radiator hoses from the coolant reservoir. so i guess its shooting the coolant out of the reservoir.

- when i park the car, shut down the engine i can look at the reservoir and notice the fluid level rising, way over max. sometimes it presses the water out of the reservoir too. when i let the fan running, it doesn't rise that high and quick.

- after the engine cooled down, all the coolant in the reservoir is sucked back into the radiator.

i allready changed following think:

- thermostat
- radiator core
- hoses
- headgasket (had some trouble with it too)
- water pump

is it possible that the spring or gasket of the radiator cap is not working properly and thats the reason why i had the coolant overflow?

or do i have a cooling problem in general? is it possible that my half size radiator is not able to cool the engine enough?

what do you suggest... please help :-) i have no ideas anymore.
The problem is, that the gasket of my rad. cap is very old and i guess its broken (see above) but i can't find another one to just simply replace. if i have to check that i have to change the cap type completely on the radiator.

Thanks
Malte.

 

up for some help...

 

why can't you find a cap? Theres tons of companies that sell them.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by coneheadsracing &raquo;</TD></TR><TR><TD CLASS="quote">why can't you find a cap? Theres tons of companies that sell them.</TD></TR></TABLE>

i don't know, the intake port of my radiator is not a standard one. Its bigger then the honda ports. I've found a company that sells caps like this but unfortunatly is the gasket not big enough and i get the same problem as with my old cap...

if nobody has another idea about what error in the cooling system can cause this symphoms i will try to weld another port on the radiator... but i only want to do this if its the only solution...

 

i have new news, maybe someone has an idea.
i have found a company which sells a radiator cap that fits to my radiator.
i've orderes a new cap from them with 20psi pressure rating.
my stock one has (i guess) 13psi but the radiator can hold the 20psi without to blow.

with my old cap i have the sympthoms described above: spray out of my reservoir when crusing the highway with aprox. 100km/h

with the new cap, i have no problems with spray around the reservoir anymore, but the water is pressed out of the pressure releave valve on top of the radiator cap and around the neck of the radiator where the cap fits inside the radiator.

the cap is correct and should seal the radiator correctly (radiator company double checked that) and coolant temps are around 220°F when crusing on the highway when it is aprox. 30°C ambient temperature. so i think its a bit too hot.

now my questions? what can cause the pressure releave valve to open? maybe damaged? is it even possible that water builds more then 20psi of pressure when its around 220°F?

what can cause the leak?

the radiator company give me the advise to check the whole thing with a 17psi radiator cap but i'am not sure if that helps me

headgasket is ok, everything is fine...
radiator size is: 15" x 12,5" x 1,3" (net size)

i don't know where too look for anymore.

 

did you bleed ur cooling system properly ?

 

In your original post you sad you replaced the headgasket but had isssues... what issues?

I"ve replaced a headgasket before, and it didn't seal up, and was pushing fluid out into the resivoir. Changed it again, with copper stuff, and it sealed up.

 

repalce the cap. alreayd had same issue with anotehr guy on here and it resovled his problem. I've seen the cap not holding pressure properly and that canc asue the fluid to boil pre-maturely. so try a new cap.

 

hi,

the system is bleeded correctly. but i have the problem that with the 20psi (new) cap he doesn't pull out fluid from the reservoir either and so he is sucking air when cooling down each time. not many but a bit every time...

the headgasket is sealing correctly because i'am running with a different engine until my new engine is build and the engine i'am running now was running properly in a stock civic until the day it was build in my car.

@oscarmayer: what did you mean with change the cap? do you think its the pressure rating of the cap (too high) or just to change the cap for the case i get a broken one?
what did you mean with pre-maturely? didn't know that word... :-)

Thanks
Malte

 

change the cap incase yours is broken. it may resolve your issues.