Stant part# for 16 PSI radiator cap?

Anybody have the Stant part number for a 16PSI radiator cap that will fit a '91 xj with 4.0 HO?

All the websites keep pulling up a 13 PSI.

Thanks!

Stant # 10230 or Napa # 703-1698

I just called Napa and asked them.....

I have a 94 XJ with 4L 6 cylinder.
Does it need 13 or 16 PSI radiator cap?

AdamG8GXP said:

I have a 94 XJ with 4L 6 cylinder.
Does it need 13 or 16 PSI radiator cap?

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13 psi is considered stock. Some people like to use a 16 psi cap. As stated above, it's most important that you don't neglect the caps as they wear out and can cause overheating problems that can send some poor guys on a wild goose chase.

Mine is worn out. I can tell it is bad because when I put a new one in the radiator leaked a lot on the side where metal meets plastic. So its back to old cap. It doesn't overheat and leak now.

That doesn't seem like a good long-term solution...........

Sooner or later, and who knows where, that radiator is gonna let go even with the crappy cap on it. Tow bill then will probably be more than a new radiator now.

Here is what came from the factory for 6-cyl engines:

84-86 -- 13 PSI
87-90 -- 15 PSI (Closed cooling system)
91-95 -- 13 PSI
96-01 -- 16 PSI

Note that they jumped it to 16 psi in '96. But to the best of my knowledge, there weren't any real changes to the cooling system between 95 and 96. CSF lists the same radiators for 95 and 96. So I guess in 1996, the Jeep engineers just decided 16 PSI was a better way to go. Either way, I don't think it makes a big difference. The extra 3 PSI only raises your boiling point by 9 degrees.

I redid my whole cooling system this spring in preparation for the hot Vegas summer. Summer comes along and bam the temp would creep more into the warm zone than I'd like.

Climbing long hi way grades with a/c would creep it up to the 220 mark.

Slapped on a 16psi stant cap and it doesn't go past 215 in any situation.

9 degrees is a big difference. At 72 degrees most people are nice and cool add just 9 degrees and most people are too warm.

Same for the engine. At 210 degrees nice and normal. Add just just 9 more degrees and shes running too warm for comfort.

Down here in the desert makes you realize how gigantic a 10 degree difference is.

702XJcruiser said:

I redid my whole cooling system this spring in preparation for the hot Vegas summer. Summer comes along and bam the temp would creep more into the warm zone than I'd like.

Climbing long hi way grades with a/c would creep it up to the 220 mark.

Slapped on a 16psi stant cap and it doesn't go past 215 in any situation.

9 degrees is a big difference. At 72 degrees most people are nice and cool add just 9 degrees and most people are too warm.

Same for the engine. At 210 degrees nice and normal. Add just just 9 more degrees and shes running too warm for comfort.

Down here in the desert makes you realize how gigantic a 10 degree difference is.

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Thanks for your input. I didn't say that it would change your engine temperature by 9 degrees. I said it would raise the boiling point of your coolant by 9 degrees. Big difference.

100% Water boils at 212* F. Mixing 50/50 with Ethlyne glycol raises the boiling point to 225* F. Raising the pressure to 13 PSI raises the boiling point to 264* F. Adding another 3 PSI raises the boiling point to 273*.

If your cooling system is functioning even halfway well, you should never hit 264* (the boiling point at 13 PSI). If you are hitting 264*, you've got problems that need to be fixed, and an extra 3 PSI won't fix it.

But I am NOT saying people should run 13 psi or 16 psi. Run whichever cap you prefer. I'm just saying it won't fix problems with an overheating system. I've had a 13 PSI cap on my radiator for the past 6 years, and I've never seen the temps go over the 210 mark, even in 115+ degree heat in the Mexican desert or climbing mountain trails here in Montana with the temp around 100* F. I'm installing a brass flushing tee to my system, going to flush it all out and change the thermostat and cap. This time I'll run the 16 psi cap, simply because so many people swear by it. But I honestly don't think it will make any real difference to my system.

The real issue is making sure your cooling system is in good shape. There are a million threads describing how to do that ... I won't repeat it here. If your cooling system is in good shape, you'll be fine with either a 13 or 16 psi cap.