Last year I went through the entire cooling system, due to cracked head on 01. Replaced head/gasket/bolts, etc. Also installed new radiator, hoses, thermostat, thermostat housing, water pump. No issues, until last week.

It has recently gotten pretty cold here in central IL, so I went out before work to start it up, let it run for 15 minutes or so. I came back out to leave, and noticed spots on the ground under the sway bar, so I bent down to see what it was. Coolant, and lots of it. It had sprayed all over the front of the engine so I couldn't located where it was coming from initially. Rinsed it all down and drove it to work. Held temperature just fine, didn't act any different that normal. Still had about an inch of coolant in the bottom of the reservoir. It has not leaked since... I can see where it came from, both ends of the upper radiator hose as there is coolant residue sprayed down the passengers side of the radiator, and also leaked down the outside of the thermostat housing. I checked the clamps, they are tight, I let it warm up, and grabbed that hose and wiggled it back and forth to see if it would start to leak... nothing.

I'm kind of at a loss as to how in the world this thing can decide to leak like crazy for just a short period of time, and then seal back up like nothing ever happened... have any of you ever seen this before? Any thoughts? I'm kind of at a loss.

Thanks!

 

Sounds like something pressure related. I would rent a pressure tester to make sure there are not any leaks.

 

You can do a leak down test on the cooling system. Most auto parts stores will rent you the tool for its cost then you get a complete refund when you take it back.

 

Thanks for the suggestions, I may go that route. What would cause a pressure spike in a cooling system though? Shouldn't it remain pretty static?

 

May not have been a variation in pressure. I had a come and go leak for about a month. Reservoir lost very little coolant. Turns out my radiator had about a 4" crack in the right side. A pressure test will tell you what's wrong.

 

Sounds good man, thanks for the response. I'll go that route first.

Only other things I can think of that would cause a pressure increase would be leaking compression into the cooling system or a bad rad cap... but I'd have a difficult time believing either of those given the work that was done last year.

I'll see what the pressure test reveals.

Thanks

 

Good luck.