Spontaneous radiator combustion.

Awox · #1 05-03-2010, 04:27 PM

My radiator just blew up!

I am currently blaming my radiator cap. Earlier on in the day, the old old old old rubber radiator hose sprung a leak. 20 bucks later that was fixed and I went home. 100+ mile drive. No sweat.

I let the car cool down an hour or so then went to the store. I was sitting at a stoplight, for a while, the temperature needle moved up a bit, but not much, nowhere near the red, but just a bit higher than normal. I just watched it very slowly inch up. Then when i stepped on the gas when the light turned green. KABOOM

Coolant everywhere, the force of the explosion tore up the insulation on the top of the hood. It looks like it's only the top plastic part that actually blew up. Is that specifically replaceable? Or does the whole radiator have to go?

I am currently blaming the fans for not coming on from possibly being sprayed with coolant earlier in the day, because they weren't on at all when I was checking out the car after the radiator blowout. That and coincidental radiator cap failure, possibly some grit got in it while i was filling the radiator back up?

Does this sound about right or could this be a more devious plot by SVX gremlins?

SoCal LS-L · #2 05-03-2010, 04:38 PM

Head gasket.... sorry

immortal_suby · #3 05-03-2010, 05:50 PM

Possibly a head gasket but don't rule out a sticking thermostat. I had mine blow up a few radiator hoses this winter before replacing the thermostat fixed the problem.

Blacky · #4 05-03-2010, 05:53 PM

The whole radiator must be replaced. There are excellent ones on Ebay for as little as $138.00. I've bought 2 of them, one for each SVX.
Check the fan operation. There's a fuse marked A/C in the under hood box which controls the fans also.

SoCal LS-L · #5 05-03-2010, 06:32 PM

The fact that it blew so violently without even being very far overheated, and as he stepped on the gas, tells me the engine compression was forced into the system.

I wouldnt drop the cash on a new radiator until you have the engine block tested by a shop (or do it yourself) or you risk the same thing happening again to the new radiator. A stuck thermostat will NOT cause cooling system pressure to blow out a radiator, the cap would relieve the pressure into the reserve tank. If the cap stuck, the coolant/water mixture would have to be SCORCHING hot to boil so violently that it exploded the radiator in that manner. According to the OP, it was "just a bit" higher than normal on the gauge.

Just sayin.... get the engine tested with a block tester or a smog machine to check for hydrocarbons at the radiator fill neck.

immortal_suby · #6 05-03-2010, 06:46 PM

The head gasket seems more likely to be the culprit, but I've personally experienced a bad thermostat blow apart more than one top radiator hose with the symptoms he described. Coolant wasn't extremely hot, overflow tank wasn't overflowed. I replaced the cap first thinking that was it, but then it happened again. It couldn't blow out my PWR though...

The old plastic top radiators are weak to begin with, and the older they get they are prone to crack. I believe that the same amount of pressure that it took to blow apart the new hoses I put on mine when the thermostat was failing could have easily destroyed a deteriorated top plastic tank.

Awox · #7 05-03-2010, 09:02 PM

This sucks....

You guys may be right about the head gasket, because the temp gauge needle was at maybe 70% to the top, still plenty of room to go till it got to the red. Not sure why though that the radiator cap didn't vent anything.

Man...

This is really saddening. My first SVX ever, it has none of the usual defects...but the same problem as the Legacy GT it is replacing.

This is frustrating, gah.