Do I Need A NEW RAD CAP?

[Morcos]

OK heres the deal,
My mom's plymouth vogageur 3.0L was slightly over heating, so just 45 min ago, i flushed her rad fluid and topped up and burped...

It doesnt over heat as much but it is above the normal that is used to be. (the needle)

I drove the car last week and when i get out, i would smell a slight odor of rad fluid, so i look under the hood, to find slight vapour getting out the cap!

my question:
1-is this leading to lose a bit of fluid"?
2-is this a cause of over heating according to the rule where when pressure in system increases the boiling point will increase. therefore if no leak of vapor then it wont boil?

 

[55Test]

I sure hope you didn't crack or warp a head or rip a headgasket. I can't remember if the Chrysler/Mitsubishi 3 liter engines have iron or aluminum heads.

 

[Morcos]

the vapour only comes out from the cap

 

[1maniac]

How old is the cap? The rubber seal and spring degrade over time and the cap needs replaced. If it were mine I'd drop the $7.00 or so and spring for a new one.

 

[Morcos]

the cap is 7-8 years old, but it looks good
spring is not rusted, and gasket is not ripped or gooey, very weird

 

[55Test]

Go ahead and replace it. Chances are by now the seal has started to degrade, could be causing what you're seeing.

 

[srivett]

I would go down to the dealer and ask them to test it. If it fails they are gonna expect you to buy one from them but it is a fair trade for free labour.

Steve

 

[BlazerLT]

Install the new cap, you are seeing exactly what happened to my truck and the cap was the problem and air pockets in the cooling system.

Just keep the overflow tank full and monitor for a week and keep topping the overflow tank up as the properly pressurized system displaces the air for coolant.

 

[Morcos]

thx guys. i will buy a cap tommorow, should i buy a reg cap or a high vapor one?

 

[Morcos]

i changed the cap, and tested the thermostat. the vapor is still comming but it turns out it wasnt comming from the cap, its comming from the rad itself. does anyone have any ideaS?

 

[BlazerLT]

yea, new rad.

And don't dump that stop leak crap in their.

 

[Morcos]

whats wrong with the rad? cant i get it "boiled/cleaned"?

 

[ZR2RANDO]

Morcos,
sounds like the radiator has a pinhole/leak. That is why the vapor is visible coming from the rad, and why the above advice about NOT using a stopleak (which I agree with as well).
Leaks in radiators are tough to fix properly, usually just better to replace them,,,,good possibility it is partially clogged as well.
Good luck with it
Rando

 

[srivett]

If the radiator is in really bad shape it will pop somewhere else after repairing it. I was not aware of there being 2 styles of rad caps.

Steve

 

[LubeOiler]

And don't dump that stop leak crap in their. why the above advice about NOT using a stopleak (which I agree with as well). Ok Ok you'all agree that Barrs shouldn't be used for a very small pinhole type leak right. But to keep adding antifreeze to the system is not cheap anymore either. Todays cars must be aweful sensitive to fixing a leak. The old days they could poor a stop leak in and drive for years with no problem. That is why I wondered about those tabs. How come those work better with less chance of a clog.I tried the Barrs and it caused the gague to move to the 3/4 mark from 1/2. How much hotter is this

I will change my 11 year old raditor cap and see if that too helps but if it runs a little hotter no big deal.I use good oil it can take the heat. If I really was so worried about it I would add water wetter or take out the thermostat.These are things in the old days you could do were effictive but today things go haywire the way their made.

 

[JHZR2]

GM puts the organic tabs into every car they sell... $1.47 from the dealer...

JMH