Radiator go BOOM! (1 Viewer)

[OLD DAWG]

My wife's 80 had a massive top tank explosion on Friday. I wasn't with her but her and the kids were heading out on a day trip to visit an old neighbor. They had went around 100mi and had already went over 2 passes that were around 10k ft without a problem. They were heading up Monarch pass on the Gunnison side when she said it felt and sounded like they hit a a huge chunk of snow. Well, to make a long story short the top tank actually blew off a large piece which still had the radiator cap attached plus it split all the way across the plastic. She said the temp gauge had been setting fine around the 1/2 point and it had been running great and shee happened to be near a pullover and shut it off immediately. Since I was stuck at work we had a tow company flat bed it back home(that ain't cheap). Any one else ever have anything like this happen? I've been working on or around vehicles for 40 years and this was a 1st for me.

 

[PNGCRUISER]

Never have had this happen, mine had 250 on the original engine / head gasket. How many miles are on it, and has it had the headgasket replaced yet? (also what year?)

 

[kerrye]

My plastic top tank spot recently. Not as dramatic and I've also never heard of an explosion like yours. I had my headgasket done a year ago. I thought maybe the hot gases in the system had weakened the plastic.

 

[sky90]

Pressured leaks in top tanks..yes. Explode..no

Changed my top tank once when noted a slight change in color of the 'plastic'

 

[Mark W]

I have seen a couple of the plastic '80 radiators explode.

Ripped the top tank apart both times.

Both blew head gaskets that let combustion pressure into the cooling system.

Apparently it built faster than the pressure relief cap could bleed off.

What struck me as odd is that hoses did not fail first.


Mark...

 

[Rwhat]

POSSIBLE the head gasket went or started to go. The pressure build up of combustion gases built up in the cooling system and blew your radiator.

 

[Rwhat]

Mark W, I wonder how much pressure actually builds up. The cap is rated to 14-16 psi plus you have the line to the over flow bottle. That must be a good amount of pressure built up even with it bleeding off out the cap and overflow.

I think the hoses would be able to handle alot of psi, I wonder what the outcome would be with a aftermarket radiator..

 

[Mark W]

No matter what the relief pressure is, if the cap bleeds it slower that the blown head gasket lets it in... it will build all the way to full combustion chamber pressure if nothing fails before this point.


Mark...

 

[OLD DAWG]

It's a 97 with 98K. Supposedly the head gasket was changed at around 83k and there are signs that it was changed(exhaust/intake nuts marked up, new cam cover seals etc). I changed oil 2 days before it happened and had no signs of coolant in the oil or oil in the radiator nor any signs of coolant in the oil after it got home. I'm hoping that perhaps the radiator tank had a flaw in it some where and I can get by changing just the radiator and shroud and hoses etc. But knowing my luck it toasted the whole whole thing. In wihch case Skrew it. I'll pull the built 1 tons & big block out of my rusty old K5 and go Krush a few Jeeps!

 

[Mark W]

I would not assume that it is a blown head gasket that caused this. That is what I have seen in two cases. But that is a pretty small sample.


Mark...

 

[Offroads4x4]

I have to agree with the comments above on head gasket building up pressure and pop.

But another thought is:

The radiator could of been bumped around during R&R of the head and gasket install or if it was cleaned and rodded and they may of not clamped the top just right.

 

[Mark W]

The ones I have dealt with did not fail at the seam. The plastic ripped and tore. and in these two cases there had been no significant work done under the hoods.

Does anyone even rod radiators like these?


Mark...

 

[kidglove13]

Mine let loose from age and burst not as dramatic and it was right on top of the tank not at the seams
Put a new metal one in and all was well.

 

[80t0ylc]

........ I'm hoping that perhaps the radiator tank had a flaw in it some where and I can get by changing just the radiator and shroud and hoses etc. But knowing my luck it toasted the whole whole thing. ........

If she shut it down that quick, I'd bet the radiator, coolant and your nerves (her's and your's) are the only casualties. It wouldn't hurt to change hoses, too, depending on their age. I've never been comfortable with plastic tanks on radiators. One thing's for sure - whatever the reason for the failure, plastic does not give much warning before it breaks. And when it fractures, the hole or crack is usually substantial and extremely hard, if not impossible, to do a field fix.

 

[OLD DAWG]

I figured first replace the rad, shroud, hoses, and belts run it without a cap (in the driveway of course. 1 tow bill was enough) and watch for bubbles showing up. I guess the funniest part of the whole thing was when it happened the mother-in-law that an explosion was coming and started to bail out before it came to a stop. Now that would have been something for U-tube!