98 Integra LS. I recently built my head (port and polish / new valves / springs and retainers / new cams) and after I put everything back together my car keeps over heating. When I put the head back on I replaced the water pump, thermostat, and thermostat gasket. My problem is my fan wont come on, bottom hose is cold, and the thermostat isnt opening up. Ive tried 2 different thermostats and I checked both of them in boiling water, so im guessing this is not my problem...burping the radiator doesnt seem to help anything. Could my new water pump be bad? Or do I have a clogged radiator? Any help is appreciated...

 

What happens if you temporarily assemble the thermostat housing without the thermostat? Does coolant then flow properly?

Also, what happens if you move the heater lever to max heat? Does this prevent overheating?

 

heater lever is at max heat. if i cant figure something out soon im just going to remove thermostat and drive to a shop...

 

Sounds like you are just not having any luck bleeding the system. I have had this happen many times at the shop. Remove the highest hose in the system and fill your rad until coolant start coming out said hose. That should make sure you have as much coolant as possible in the system. Make sure your heater valve is open. That is the valve on the heater hose. Make sure you put your tstat in the correct way. Is your fan plugged in? Can you manually make the fan work? Is your temp sensor hooked up?

run the engine with the rad cap off and let the system bubble out. Periodically rev the engine to 2500 and back just to see if you can disturb any bubbles.

The reason I think it is just a bubble is because your lower rad hose is not getting any flow and a bubble will cause that. Also feel your heater hose and make sure they are getting hot as well.

 

Yeah, if removal of the thermostat doesn't restore proper coolant flow as determined by heating of the lower radiator hose, then there must be a cooling system obstruction (it seems unlikely that a new water pump would fail). As you say, try flushing the radiator.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by biggee &raquo;</TD></TR><TR><TD CLASS="quote">Sounds like you are just not having any luck bleeding the system. I have had this happen many times at the shop. Remove the highest hose in the system and fill your rad until coolant start coming out said hose. That should make sure you have as much coolant as possible in the system. Make sure your heater valve is open. That is the valve on the heater hose. Make sure you put your tstat in the correct way. Is your fan plugged in? Can you manually make the fan work? Is your temp sensor hooked up?</TD></TR></TABLE>

So you're saying flush the radiator from the top hose that goes from the rad to the head? Ive tried that. I do believe that there is a bubble in the cooling system because i didnt flush it properly. My fan/temp sensor are plugged in and i manually checked the fan with a drill battery. The temp sensor broke during head removal, but i replaced prior to having this problem before starting up the car. I think that im just having poor luck getting this air bubble out of the system.

 

Ive tried flushing the block and the radiator and letting the coolant bubble up and top off. patients is not my problem here because i sat and watched it for over an hour this morning. this morning i removed the thermostat and tried seeing if i could get anything out of the bottom hose - which was a success. i believe this indicates my water pump is working. so when i got home from work i put the thermostat back in and filled the upper radiator hose completely with coolant. im not seeing any more air bubbles come out of the neck. ive checked for any vacuum leaks and have found nothing. to add insult to injury i just popped codes p0172 and p0170. since these are fuel system codes i dont think they have any relation to my coolant problem. im GUESSING they came from either the cams being un-tuned or the fact that i adjusted the valves to the factory spec and they are .5mm oversize. im not sure yet but my bigger problem right now is the coolant issue. any more help?

 

I assume you are saying that the engine still overheats?

The O2 sensor codes might be due to connectors that are wet with coolant and therefore shorting out. Try drying the sensor connectors.

Is the overheating problem possibly related to the newly installed head?


Modified by RonJ@HT at 7:27 PM 3/10/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RonJ@HT &raquo;</TD></TR><TR><TD CLASS="quote">I assume you are saying that the engine still overheats?

The O2 sensor codes might be due to connectors that wet with coolant and therefore shorting out. Try drying the sensor connectors.

Is the overheating problem possibly related to the newly installed head?</TD></TR></TABLE>
Thats true about the wet o2 sensors i didnt think about it. if the code pops back up ill look into it more - i just dont see how you can throw a lean and a rich code at the same time unless your ecu is retarded. Engine isnt overheating without thermostat so until i can get some better ideas as to why the thermostat wont open up im just going to ride without it... however i DO think that this has something to do with the reinstallation of my head because i never had this problem before...

 

di you install your head gasket correctly? do all the water ports line up properly? Can you even install it backwards?

 

Have you tried filling it with coolant through the top radiator hose? I had that problem with my D15B when trying to fill through the radiator.

 

it kinda sounds like a blown headgasket but i mean check all the easy things first

 

yeah ive tried filling the motor up through the upper radiator hose -- no change. <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by D16SiHatch &raquo;</TD></TR><TR><TD CLASS="quote">it kinda sounds like a blown headgasket but i mean check all the easy things first</TD></TR></TABLE>
I just replaced the head gasket along with every other gasket above the head when i put everything back together. My gasket is in correctly -- both of the coolant pins are in and the gasket is properly lined up. My car runs fine without the thermostat...which is what ive been doing for the past few days. i would just rather not let this beat me and get it to work properly. ive since then replaced the 2 temp sensors on the head and that hasnt changed anything. Possibly could be the sensor on the thermostat housing? My next approach is to try a thermostat from honda....

 

i had the same prob. i had a huge clog in my radiator n my fan switch was out...check your radiator... both side have to be hot...if there is a drastic change from side to side change it... i first tryed my fan switch( it is what gets the thermostat to open)

 

This may be a dumb question but are you putting your tstat in backwards?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dannysolis92005 &raquo;</TD></TR><TR><TD CLASS="quote">i had the same prob. i had a huge clog in my radiator n my fan switch was out...check your radiator... both side have to be hot...if there is a drastic change from side to side change it... i first tryed my fan switch( it is what gets the thermostat to open)</TD></TR></TABLE>

good idea about the fan switch. the temp of the coolant in the block is what makes the thermostat open but the fan switch could possibly have something to do whats going on with my ride - its the only thing i havent replaced yet other than the radiator...ill try that but if it doesnt work i think im just going to get a honda head gasket. ill also check around the radiator for any cold spots. ill let ya know..thanks man!

 

hi hollums2k,

can you update on this problem. i think i got the same problem as you are. it suddenly happen to me after i change the thermostat few months ago. i have check the thermostat in the boiling water, it work fine. don't know what it cause why it wont open when i installed it to the engine. now, i temporarily remove that thermostat until i can find the root cause. hope you can update on your finding.

thanks dude.

 

ok here is my problem i just replace my motor its a turbo ls stock motor, theres a new oem water pump and low temp arc t stat and head gasket (which is on correctly just with out the dowel pins, so my head studs lined up the gasket) . but overheat instantly after 1 min of driving, now from cold start up to overheating the lower radiator hose is cold. so i switch the t stat and nothing changed still overheats. its like coolant not flowing so tomorrow i am going to flush the radiator and the block an see what happens. and i don't even want to drive without the t stat cause i shouldn't have to.an the fan kicks on, anyone have any other idea?