05ljnj

Just got my cherokee the other day. '00 82k on it. I bought it with my buddy and he said that since these have the head probs, lets do a coolant flush. We got it delivered to his shop and he did the coolant flush and changed the thermostat and gasket. As well as the coolant temp sending unit I believe.

Now since there were no plates on it he couldn't drive it much aside from idling it. I grabbed it yesterday, started reading about head issues so i marked the overflow bottle. Now its down about a 1/4" yesterday and today when i looked at it before work probably another inch or so. Could this be a the system working out the air bubbles from the coolant flush? I don't see any coolant on the ground..

Also he mentioned he put in two gallons of coolant and the resevoir doesn't look like that has new fluid so I am guessing he just drained the radiator and put in new. Any thoughts would help. I am wondering if I should do some testing (leakdown, compression, pressure, etc)

SlackJaw

i would just keep an eye on the coolant for a few more days...most likely just air just trapped in the system. also keep an eye on your oil.

if you're really worried, do a pressure test on the system or do a test on your coolant to see if there are exhaust gas present.

UserID6095

Testing never hurts.

kemjeep

x2 on above and take off coolant recovery bottle and give good cleaning my 2cts. also replace rad. cap

lfhoward

I just went through replacing a cracked head on my 2000. No fun. But a lot more fun than ignoring it, then wiping out the bearings and having to replace those!

Your slow coolant leak might be from a cracked head or it might not. Here's how you can tell:
1) If it's just your new coolant settling in the radiator, it will go down and inch or two but stabilize after the first day or so. If the head is cracked, coolant will keep on disappearing slowly and you won't see any on the ground. Mine went from "Full" to "Add" each week while it was leaking. Keep in mind that coolant expands when hot, so always check it at the same temperature for an accurate reading.
2) If you have the cracked head problem, your coolant will slowly leak into your hot oil and evaporate. In my case the oil level did not rise, but the condition of my oil deteriorated, leading to excess wear. Blackstone Labs (http://www.blackstone-labs.com/) can test a sample of your engine oil for you so you can definitively know if your coolant is going there. It costs $25 and the kit is free. They helped me catch my cracked head before too much bearing damage occurred.

Hope this helps. The user tjwalker seems to be one of CF's foremost experts on the 0331 head problem. I'd say search for his posts to get a good background on the issue. Good luck! -LFH

lfhoward

I should mention that if you find out you have coolant in your oil it could either be a bad head gasket or a cracked head. A pressure test will tell you if your head is actually cracked, if you get to that point. The pressure test is something a machine shop or well equipped auto mechanic can do.

DaddyCat

Good advice from all and I will repeat it is normal for the overflow tank level to go down as the air is cleared from the coolant system for a few warm up/cool down cycles. If after several cycles you are seeing continued loss of coolant something is wrong. Cracked head, loose hoses, leaking heater core are all possibilities.