Why is my TJ ruining radiators?

[WLDRIDE]

Surly the answer cant be because its not OEM? 2 radiators in a short time span of 5 weeks splitting in the same place not including the original that went out first.
Unless its a bad batch of poorly manufactured radiators I dont think the fitter can just keep fitting new ones under warranty?

EXACTLY!! You are tracking with me. This is why I need to figure out what is causing this.

 

[WLDRIDE]

Surly the answer cant be because its not OEM? 2 radiators in a short time span of 5 weeks splitting in the same place not including the original that went out first.
Unless its a bad batch of poorly manufactured radiators I dont think the fitter can just keep fitting new ones under warranty?

EXACTLY!! You are tracking with me. This is why I need to find out what is causing this. That's the point of this post.

 

[P man]

The only thing I can think of is too much pressure build up...I would think a shop could hook up a tool to the filler neck and let it run while monitoring pressure. How about your radiator cap is it the correct pressure?

 

[Irun]

I agree. I've never had issues with an aftermarket radiator until I had a TJ with one. And even if the radiators are crappy, they probably aren't failing in 2 weeks on every TJ they're being installed on.

As much as I like to recommend it, I'd hate to suggest an expensive mopar radiator and have that one bust open in 2 weeks like the others.

Are there any mods to the front end that might change the rigidity of the grill and the way it moves as the chassis flexes over terrain? Pre-JK Wranglers were quite unique in the structure of the front end when compared to how most other vehicles are put together.

I've had an aftermarket radiator in my LJ for 8 years and had zero issues. There's a story behind that, but I'll leave that for another thread!

 

[Fargo]

As mentioned already, I would be sure to replace all the hoses and the cap to make sure its not something else. Might be a good time to have it flushed as well. Just to make sure its not something stopping the flow and causing over pressurization.

Oh, also check to see if the new hose (I think its the bottom) has the support spring in it. If they used a cheap hose it could collapse.

 

[Irun]

To the OP, I've always had the best luck with radiators when the entire cooling system is addressed. That is, if I go to the trouble of replacing the radiator, I replace everything else cooling related. I've never had an issue when following that strategy.

 

[Jerry Bransford]

... also check to see if the new hose (I think its the bottom) has the support spring in it. If they used a cheap hose it could collapse.

I haven't seen a new hose with a spring in years. Gates told me that modern rubber formulations eliminated the need for a spring to resist hose collapse from normal pressure changes.

 

[Fargo]

Thanks Jerry. I was hoping you would chime in on that. It has been so long since I replaced my radiator I couldn't remember for sure if my new hose had the spring or not. I just remembered my OEM did and there was some discussion about it at the time.

However, while that may be true for Gates and name brand hoses, I wonder if some of the cheap Chineese hoses might be of cheaper quality that they could cause issues. I would be sure to stick with quality hoses.

 

[jeepins]

Jerry, post one more time with an 'uh huh' or 'word' or 'damn right' so you get 20k posts and a lollypop!

 

[MutantNinjaTJ]

a bad head gasket or a crack in the head will cause excessive pressure in the cooling system sometimes.

 

[JMT]

BUT, discussions of good and bad radiator brands, good and bad shops, and warrantees aside... any ideas on why my TJ might do this other than just bad luck?

No, no mods like that. It still has the stock front bumper. And, because the shop is a good one, and stands behind their work, I know that they won't want to just do the same thing a third time without figuring this out first.

Try replacing the radiator cap. It may be faulty.

 

[JMT]

@WLDRYDE , I found this on the inter webs, it might explain why it’s happening at night during cool down.

“You may have a bad radiator cap if the radiator hose collapses. The vacuum won't be released by the radiator cap properly and it will cause the radiator hose to collapse during the cooling down period.”