Closed Coolant System Kicking My Rear End...help Me Guys

[Kubic40]

1988 mj...121k...5speed.......Before i get flammed, I'm not new to the mechanic world in any way sense or forum, but this is my first jeep and closed coolant system i've ever had the pleasure of owning.

 

Just bought me a mj last weekend for $1000....and now i have some closed system issues.

 

When i let it sit and idle and warm up, it starts to completely spew coolant from the bottle.....i canked down the larger cap and now it seeps out of the little cap hahaha.....yes the fan blows, all the lines get pretty hot so water pump works, A/c fan is in the works of being wired up for extra cooling(like i said it never left the driveway).......oil looks good......no coolant smell(maple syrup smell yummmm)......no leaks by the head gasket or freeze plugs.

 

Now the coolant bottle was empty when i bought it, and yes i never refilled it yet due to the this new issue that is going on.

 

My question is will the system not being "purped" properly and having air in the system cause this to happen? 

 

ANY help is welcome.....Please don't tell me the head gasket it done for!!!!

 

 

 

Thank you

 

-ED

 

 

p.s. The dang jeep love has already kicked in =)

 

 

 

[Strokermjcomanche]

On the closed system you're only supposed to fill the overflow bottle about half way when cold .

 

 

If your cap still leaks cruiser54 preaches about a Volvo cap that can be used .

[cruiser54]

Big cap and little cap?

An 88 only has one cap, the one on the bottle on the passenger side firewall. If that pukes, try  Napa 703-1396 on the bottle . 

[Kubic40]

Big cap and little cap?

An 88 only has one cap, the one on the bottle on the passenger side firewall. If that pukes, try  Napa 703-1396 on the bottle . 

 

 

no sir,it has two caps....a large one and a smaller cap that has like a plastic slide attached to it underneath.

 

could it be a different bottle yes considering half the truck is botched to heck with wires and parts.

 

i can get a picture tomorrow

[Kubic40]

 

 

 

 

 

[Strokermjcomanche]

The black peice is the cap .

 

The other white peice looks like a low coolant sensor . Never seen one of those in the coolant tank . Do you have the info center where the clock goes? Or is your low coolant light on?

[BootsNTrucks]

I would swap to an open system. Cost about $50 (parts) + $345 (fancy all aluminum radiator). Does wonders for the truck in stop and go traffic on hot days.

[Kubic40]

eh, i figured it wasnt the right tank.

 

 

so back to my question, why the over flow of coolant with caps firmly in place?

[cruiser54]

Crappy caps. 

 

If you replaced that bottle with one with only one cap, and used a 703-1396 cap on the new bottle from Napa, you'd probably be just fine.

[tugalo]

Might be worth a try to loosen the temp sensor  and refill the system to ensure that you do not have air trapped in the head...

 

my solution to the crappy bottle was to install one from a mid-90's Mopar.  The Mopar bottle is made from HEAVY nylon, has a different shape, and a REAL radiator cap.  You remove the original bottle, remove the bracket holding it, and mount the new bottle directly to the firewall in the original location.