Thermostat question

[jlspr]

I think I'm gonna grab a used radiator from a local yard that will come with a warranty. They already have them off the cars and cleaned up. If it ends up being the headgasket then I may just order a d15b jdm engine since most are low mileage engines. All depends on how much cash I save up between now and then.

[user removed]

Lets not start throwing parts at the car only to find out they do not solve the problem.

Get the system filled with 50-50 with everything tight. Start it up and make sure you bleed the system until you get no air or bubbles out of the bleeder.

If the temp gauge is not reading more than half way and you are not loosing coolant (checked with the vehicle cold) and the level in the recovery bottle stays at the same level and you pull the cap and it is full to the top of the point where the cap seal seats.

If the system is not bled properly and or the coolant is not close to 50-50, either of those could be your only problem.

If coolant is vanishing into thin air then the head gasket is suspect.

If the gauge shows it running hot at idle suspect head gskt.

If it runs hot the faster your sustained speed the suspect radiator as long as it is not loosing coolant.

If it boils over and overflows the coolant reservoir then it could be clogged radiator or bad gasket or a combination of both.

Bleed and fill with 50-50 even used 50-50 is fine as long as it's close to 50-50. Proper coolant mix will not boil under 13 PSI pressure until it reaches something like 256 degrees, which is why proper mix, system integrity, and a proper cap with the system bled properly are all critical and interrelated.

regards
Mech

[02ws6]

You can get a fel pro headgasket set for less than $100...

You can do the job on the cheap.. I just personally do a bit of overkill because I never want to have to get a tow.. That tow money can go towards my parts. Atleast thats how I see it..

[jlspr]

When I changed out the thermostat I used Prestone 50/50 mix. Replaced the cap with a new one. Then bled the system till I had a smooth trickle with no bubbles coming out of the bleed screw. Before the bottom hose was cold and top was hot and after they are both hot now. But it seems like the coolant is moving over to the overflow now and leaving the radiator about a half inch to an inch low. Thats why I think it could possibly be clogged since the old cap was shot maybe some of it is still inside and I didn't do a good enough job flushing it. Oil looks fine with no leaks anywhere. No white smoke either.

[jlspr]

I drove the car today 40 miles doing 55 mph today and the temp gauge was normal the whole way. Doesnt overheat at idle either.

[toc]

Don't make the mistake I did with my pulsar - replaced the head gasket before getting to the cap and seeing the cap was slightly torn (enough to stop pressure building so that the water would go through the radiator to the lower hose).

And yeh, the lower hose can be the one the thermostat blocks flow back from.

And yeh, a hotter thermostat won't hurt anything, design considerations apply including a slow acting thermostat, and the water away from the thermostat being hotter than that at the thermostat.

[user removed]

The difference between the temp of the top and bottom hoses is how effective your radiator is at removing the heat from the system. In colder weather the difference will be greater and in hot weather it will be less as coolont will flow much faster when temps get hot outside.

It may take a few cycles for the air to completely purge out of the radiator, but it should be completely full when cold after those few cycles. Make sure you do not have any leaks in the hose from the radiator neck to the recovery bottle. I use a magic marker on the recovery bottle to mark the coolant level and watch it for a few days to make sure it is the same. Remember increasing ambient temperatures will cause the level to rise slightly but not much. What you don't want to see is the level dropping without any apparent leaks. That is an indicator of head gasket issues.

Run the heater, even with the windows open to fully purge the system.

regards
Mech

[brucepick]

Burping out the air bubbles can be challenging in a Civic.
Some have the bleeder on the upper hose connector at head. Others have it at the thermostat housing. Mine has none!

My guideline is, with engine warmed up, upper hose will be too hot to grab firmlry and keep holding it. Lower hose will let you hold on to it. Maybe not the case when 100 degrees outside but basic true.