Overheating Problem w/ Solution & Question
 

Here is a case study for you guys (and girls):

2004 Honda Civic EX Coupe
Fiji Blue
130,000 miles

Issue:

First Day
-First time using my heater this fall on the way to work
-Noticed that when I slowed below 20mph, my car blew COLD air -- BBRRRR
-Fans were running, coolant level was ok

Second DAY
-Overheated (didnt actually overheat, just started getting too warm for comfort ~ temp guage inching towards 3/4) == SHUT CAR OFF RIGHT AWAY
-reservoir was filled to the cap- eek
-Let my car set for 2-3 hours
-Turned my car on, with rad cap off, no air...
-After car reached operating temp, a few bubbles came up, nothing crazy


Solution:

Drove my car to the STEALERSHIP due to panic that my heater core or HG had gone...F.

Paid them $85 to "look" for the problem. They lifted my car and some air came up - "burping" the coolant. The mechanical they lift the car due to the position of the radiator in relation to the rest of the system. Next, they pressurized the system and checked for leaks. They found NONE, thank GAWD. I told them about 20,000 miles back I paid a local shop to replace my timing belt and water pump, at a cost savings to me (I too am no mechanic). They mentioned that the other shop may have put the water pump in w/o bleeding the coolant system. I had this same problem last year around this time and it just needed more coolant and the same "burp". The other shop tried to convince me last year my radiator was leaking, which the STEALERSHIP confirmed was NOT THE CASE. He said to keep a close eye on the temp guage and went ahead and flushed / replaced the fluid.

I am hoping that last year they simply did not get all the air out of the system AND I hope my water pump hasnt been damaged due to cavitation.

Status:
4 WEEKS and NO PROBLEMS.

LESSONS LEARNED:
The issues I had were caused by AIR in the system. That air, as the above members have mentioned, can get into the system multiple ways. All you can do is hope that it is one of the cheaper fixes.

I am worried that the air may have gotten into the system another way, i.e. the replaced water pump 20k ago wasnt the ROOT CAUSE of the issue.

MY QUESTION TO YOU?

Do you think I should worry about the Rad Cap, Thermostat, or WORSE the HG? Should I replace the Thermostat and Rad Cap just in case?



~~ ONLY USE *OEM* RAD CAP, THERMOSTAT, COOLANT ~~ NOTED.

Re: Overheating Problem w/ Solution & Question
 

from what i gathered the car is running fine now???

after i replaced my water pump and thermostat and drained all the coolant, it took about 400 miles of driving to "burp" all the air out of the system, during this time i would just have to simply top up the coolant in the overflow tank....

a loss of heat on a continuous basis would kind of point to a clogged heater core

Re: Overheating Problem w/ Solution & Question
 

Just where do you think that "air" could have entered the system at?
What do you think the root cause would be for this "air" getting into the system?

I do water pumps all the time. I don't seem to have trouble burping them out.

I know what I'd be checking first.

Re: Overheating Problem w/ Solution & Question
 

Thanks everyone for the help! It ended up being my head gasket...see below.


Took it to the dealer and replaced the thermostat & rad cap and it still overheated. Compression test showed loss of pressure in cylinder #2 after about 15 mins at idle, then resevoir started overflowing.

ISSUE: Head Gasket Leak :hithead:

GRAND TOTAL of $1543.77