Blowing Coolant tanks

boise49ers · Oct 20, 2005

My son has a 90 XJ with a closed system. It hasn't really over heated, but it builds so much pressure it has blown 3 plastic coolant reservoirs in 2 days. It had low coolant below the half mark and wasn't over filled. The last 2 were the after market ones, but the first was the factory Jeep GOOD one. What could cause the fast build up of pressure. The gauge reads at operating temp.

langer1 · Oct 20, 2005

boise49ers said:
My son has a 90 XJ with a closed system. It hasn't really over heated, but it builds so much pressure it has blown 3 plastic coolant reservoirs in 2 days. It had low coolant below the half mark and wasn't over filled. The last 2 were the after market ones, but the first was the factory Jeep GOOD one. What could cause the fast build up of pressure. The gauge reads at operating temp.

Head gasket high pressure leak, have it sniffed.

sidriptide · Oct 20, 2005

langer1 said:
Head gasket high pressure leak, have it sniffed.

thats what i'm thinkin.

boise49ers · Oct 20, 2005

4.o s aren't known for blowing head gaskets. Nothing happened to bring it on either. No major overheating or loss of power. It would be foamy too, wouldn't it ? I've had a blown Head gasket in an old Gremlin with a 242 and it foamed up bad. I drove it until I cracked the block. One of those expendable Cars.

boise49ers · Oct 20, 2005

What exactlly does have it sniffed mean ? ? ?

uvaldetxj · Oct 20, 2005

boise49ers said:
What exactlly does have it sniffed mean ? ? ?

have it checked out.

XJ Buzzard · Oct 20, 2005

boise49ers said:
What exactlly does have it sniffed mean ? ? ?

Exhaust gases in the cooling system. A competent shop should be able to do this.

chris

summitlt · Oct 20, 2005

Even if there was a leak and getting combustion pressures in the tank, the cap shoudl releive the pressure at some point. (16 psi? I think?)

boise49ers · Oct 20, 2005

That is what I thought, It should blow by the cap before blowing the tank. Could it just be the chinese after market are that bad ? ? ? They blew in the same spot. Plus what I forgot to mention is that it blows it after you shut it down. The water quits circulating then it builds more pressure and blows it out around the spout that connects the bottom hose.

Matthew Currie · Oct 20, 2005

Not to belabor the obvious, but have you checked to see if the cap is defective?

boise49ers · Oct 21, 2005

It was the cheap chinese shit. Got a Dealership one , burped it and it is running and cooling great. Thanks

Blowing Coolant tanks

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sidriptide

nobody of any consequence

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