Ok guys i know everyone is sick and tired of seeing another overheating thread but this one might be a lil dif. Possibly cracked CYLINDER HEAD?

Well since it was overheating i decided i need to make sure its fixed so i decided i was gonna put a lil more with it. So i went out got some full race traction bars put the new EG rad in it with new slim fan. Replaced the water pump, thermostat, rad cap, thermo sensor, and throughly cleaned the system. I also did a compression and leak down test. ALL GOOD. Compression was about 270 on all 4 cylinders and and leak down was no more than 8% on all 4 cylinders. I then bleed the system with heat on full blast extremly well about 2 times about 30 min a piece Well i thought this was def going to fix my overheating isssue. WRONG. The bastard still overheating. Its advadently building pressure somewhere becuase it fills the resivor completly up.

My heat only comes out sometimes but when it blows out cold air then it overheats. As soon as the heat blows again it begins to cool down. So obviosuly theres air in the system which causes no heat to come out when the air passes threw the heater core. THATS MY OPINION!!


So to sum it up i cant figure out what the crap is going on. Do you think theres a possible crack in the cylinder head causing air to get into the system? Thats the only thing that can be left. PLEASE HELP!!!!!

THANKS!!!




Modified by doublek at 7:34 PM 7/28/2005

 

someone has to know or have had a this problem.....i cant be the first.....

 

you pulled the head yet to have it checked for flatness as well as pressure tested? and while its out you can examine the block as well.

 

no i havent i pulled the head yet.....i was actually trying to avoid that and see if anone had any other insight before i did that......

 

what temp thermostat are you using? and is it aftermarket, or oem?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PURPLETERROR &raquo;</TD></TR><TR><TD CLASS="quote">what temp thermostat are you using? and is it aftermarket, or oem?</TD></TR></TABLE>


Im using an aftermarket one from autozone.....this is the 2nd one

 

well a few years backj my wifes gsr swapped civic had a wandering temp needle, great compression, but sometimes overheated. so i put anew theormstat in, new radiator, new fan, wired fan to be on all teh time, repalced sensors.....i wasted a LOT of time. the fix was replacing the head gasket. it was allowing exhasut into the coolant ONLY under a driving load.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">well a few years backj my wifes gsr swapped civic had a wandering temp needle, great compression, but sometimes overheated. so i put anew theormstat in, new radiator, new fan, wired fan to be on all teh time, repalced sensors.....i wasted a LOT of time. the fix was replacing the head gasket. it was allowing exhasut into the coolant ONLY under a driving load.</TD></TR></TABLE>


Humm.....well im hopping that is the prob.....would be aweosme and save alot of money. Guess imma pull the head of the this evening and replace the head gasket.....thanks bro....

 

if it is the headgasket and alowing air into the system ONLY under a load then how could we test to make sure? Is there a way to know?

Im just asking becuase if i pull my head a replace the headgasket i want to try and make sure thats the prob and not a cracked cylinder head? Who could test my cylinder head to see if its good or not?

 

You could pressurize the cooling system with one of those radiator cap testers...If it doesn't hold you eliminate each component until you get to the cyl. head. Or just pull the head and look for cracks..

 

I'm voting on a blown headgasket.

instead of running air through a leakdown tester, I say run full shop air through each cyl and see if you hear a leak from anywhere. this is what I did on a customer's car and found a blown headgasket letting cyl pressure from cyl 2 to cyl 3. make sure you're at tdc to close all the valves.

 

are the fans blowing in the right way?
have the rad pressure tested for leaks and will show u if u have busted HG.
are ur hoses new? they could collapse when running high rpms.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ekek888 &raquo;</TD></TR><TR><TD CLASS="quote">are the fans blowing in the right way?
have the rad pressure tested for leaks and will show u if u have busted HG.
are ur hoses new? they could collapse when running high rpms.
</TD></TR></TABLE>

Yeah the fans blowing the right way...hoses are not new but clear off all debris....

 

This morning i finally got a better clue on a blown headgasket........finally got some air comming out the resivor lines....bubbles like a champ. Weird thing is that no air comes out of the lines while at idle. I bleed the system. Idled for about 45 min. ALL GOOD. Took for test drive about 30 min into it the gauge skyrockets. Looked at the resivor and it was overfilled with air bubbles oozing out of it.


NOW how do i tell if its a blown headgasket or a cracked cylinder head?