Radiator Cap Failure

[Diboblo]

This is an issue that I dealt with on my 2006 SRT Charger. Seems like they are still using the same junk materials.

Issue: Radiator cap (coolant overflow tank cap) failure. The rubber gasket, in the cap, cracks and pisses out fluid.

Symptoms: Light odor of coolant. Higher operating temps, than normal.

My Cat has 90k on it and is DD. Your mileage may vary.

Quick visual inspection, when engine is COLD, should do the trick, if you want to verify condition.

As a side note, I checked the I.C. tank cap and it was good.

Here are a few pix, so you know what to look for:

Hope this helps.



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[vortecd]

something people normally don't look at

 

[Catless]

Wow that looks worse than the original cap on my 1969 Pontiac!

 

[HWDan]

Hell, you just made me go out and check my 2005 5.7

looks good, no cracks, still pliable rubber. The smaller one (like yours that isn't cracked) seems stiffer but not at any stage to crack.

I might as well order a new one for it just in case.

The last thing we want to happen on these high mileage early hemi's is to overheat and drop a valve seat.

 

[Diboblo]

Hell, you just made me go out and check my 2005 5.7

looks good, no cracks, still pliable rubber. The smaller one (like yours that isn't cracked) seems stiffer but not at any stage to crack.

I might as well order a new one for it just in case.

The last thing we want to happen on these high mileage early hemi's is to overheat and drop a valve seat.

Especially that 5.7...

Had our 05 RT Magnum for many trouble free years. It was hard to let go.

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[TraxMoe]

unless I'm wrong that second seal doesn't have anything to do with the coolant leaking, unless the primary seat is lifting because the pressure has exceeded the 21 psi rating of the cap. You may have a bigger problem than just the cap if the pressure is that high, leaking head gasket comes to mind, fan not coming on when it reaches temp, anti-freeze at excessive concentration not allowing heat transfer

 

[Old Mopar Guy]

Something else to check in the off season. Thanks Bob.

 

[Diboblo]

unless I'm wrong that second seal doesn't have anything to do with the coolant leaking, unless the primary seat is lifting because the pressure has exceeded the 21 psi rating of the cap. You may have a bigger problem than just the cap if the pressure is that high, leaking head gasket comes to mind, fan not coming on when it reaches temp, anti-freeze at excessive concentration not allowing heat transfer

Tested, today.

Let it idle and watched temps.

By 218° coolant, fan never turned on.

I guess I'll have to pull the connector, at the fan, and apply power, direct.

Anyone know if I can cycle the rad fan, with AlfaOBD?

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[Diboblo]

Tested fan with Alfaobd. No joy.

2 fan tests. I assume low and high speed.

Low speed, relay hums and no fan.

High speed, relay hums, then fan eventually comes to life.

New fan assembly, it is....

Anyone have a fan motor takeoff?

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[TraxMoe]

Tested, today.

Let it idle and watched temps.

By 218° coolant, fan never turned on.

I guess I'll have to pull the connector, at the fan, and apply power, direct.

Anyone know if I can cycle the rad fan, with AlfaOBD?

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I vaguely remember some time back there was a TSB for the fan not coming on. Don't remember which site it was though but there was much discussion about it

 

[Diboblo]

I vaguely remember some time back there was a TSB for the fan not coming on. Don't remember which site it was though but there was much discussion about it

Thanks.

I'll look it up on tech authority.

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