Ok I will try my best to explain the problem... About a month ago my fiance was driving her car to work 30 miles away and she heard it start clicking (ping) and noticed the car was pegged at high on heat. The radiator was out of fluid.. It wouldnt start again after it was off (still too hot) it was towed to a shop where they let it cool down and it started fine after.

They refilled coolant and said they tested for radiator leak and saw nothing. They supposedly pressurized it and also checked for exhaust gas in the fluid but I doubt it since they didnt charge us anything.

I bring it home and a weak later its losing fluid... I inspected and the radiator had a pinhole leak. I replaced the radiator with one from radiator.com its a OE replacement. Now fast forward 2 weeks or so and she is driving home when she head a rumbling noise for a few secs and then starts to smell radiator fluid. Now I am fairly certain the NEW 2 week old radiator had blown (broken end cap possibly). Now do I have a crappy replacement radiator or is something else wrong... All I can thing of is soo much pressure built up the radiator blew BUT why wouldnt the radiator cap blow first... could I have a head gasket leak that is pressurizing the radiator causing it to fail? Again why wouldnt the radiator cap instead release the pressure?

I am debating if I should replace the radiator again or if I have a bigger issue like blown head gasket... any recommendations?

Oh almost forgot 2005 Honda Civix Ex 85K miles

 

Have your ran it for a little while and see if the hoses expand alot?
Have you tried also the thermostat, you may have gotten a defective rad.
Have you called/emailed the company you just bought it from and tell them it busted?

 

your thermostat might now be opening thus building up pressure, thermostats are easy and cheap to replace.

 

I would replace the rad, rad cap, rad hoses, and thermostat. Be sure to bleed the cooling system. After you have done this, drive the car around for a few short trips. Check the coolant level and the oil level when the engine cools down. Hopefully your fluid levels are correct. If not, you may have check out the headgasket. Good Luck!!

 

well the radiator is new and the car has not overheated since i replaced the radiator.... I believe the first time it overheated was because of a pin hole in the rad that let the fluid leak out until it was just about empty.

After I replaced the radiator it worked fine for 2 weeks... Until last night where she said she heard like a sound that sounds like when you go down the rumbl strips on the road to wake you up but not as violent and then she smelled the radiator fluid.

I refilled the expansion tank (since it was empty) and this morning the radiator seemed to suck from it as it cooled since the radiator was full again but you can see rad fluid....

Also since the car didnt overheat again I doubt it is the thermostat... any other ideas? I may just replace it sinc it is cheap though.

 

If you are positive that the rad is ok, you should really replaced the thermostat and the radiator cap. They are cheap. You can pressure test your cooling system to see if there are any visible leaks.

 

Ok I pressure tested the system and it held fine at 15 psi for 10 minutes without the pressure dropping...

Then I set it to 0 and turned the car on and let it rise... it toped out around 8 psi. I then kept the engine revving around 2500 rpm for 5 minutes or so until I would get the engine hot... I saw it get close to 16 psi then the fans would kick in and drop it to 10... It kept going 15 - 10 - 15 - 10 as the fans kicked in it would go to 10.

Now should I apply more pressure to check for leaks since it seems the car got up to 15 psi by itself...??

One interesting not my radiator cap rated for 1.1 bars held 2.5 bars without releasing... I think I have a bad radiator cap... but the thermostat seems to be functioning... Can it function sometimes and get stuck others if it is on its way out?

For now I am going to purchase at least a new cap (maybe thats why the system leaked last night got really high in pressure until it squirted out somewhere...

Where do you recommend I purchas e the stuff honda wants 22 for cap and 44 for thermostat is that decent?

 

I may have spoken too soon...

I went back and pressure tested it again now that it was hot.... I put 17 or 18 psi when pssssssssshhhh and radiator fluid seems to be leaking from the bottom of the radiator and a lot... it didnt stop until the pressure hit 5 psi or so.. I again went up to 15 and same thing happened again...

So I am guessing the radiator (new radiator) is bad as well...

So new radiator thermostate and rad cap I guess....

 

I bought a rad and it came with cap for 90 bucks at Autozone. The thermostat cost around 15 bucks at the dealer.

 

I replaced the rad again... The dealer wanted 40 for the thermostat and didnt have any..

I gtook out the thermostat and tested it against a new one from autozone and they opened up at the same temp so I decided to keep the stock one since it was working. I replaced the rad cap since it failed the pressure test...

The cooling system held 18 psi for 10 minutes just fine...

The compression was 215 for each cylinder. So I think I just got unlucky and got a bad radiator.