I have a 2001 jeep cherokee with 107,000 miles. About 3 months ago I got a tune up and a coolant flush. My check engine light came on about a month ago and brought it into the shop. These are the codes the computer came up with:

-PO300: Random/multiple cylinder misfire
-PO301: Cylinder 1 misfire
-PO304: Cylinder 4 misfire
-PO306: Cylinder 6 misfire

Before I got the coolant flushed I don't think the previous owner never did one. So when we changed the coolant 3 months ago it came out light brown like a rusty color, and smelt horrible. We filled it up to the "FULL" line in that box. Now its right at the "ADD" line and its back to a brownish color. There's a little bit of liquid coming out of the exhaust but not that much, only some drops. Also if I start go for a 10 min drive and come back, put the car in park, and leave it at idle, there is a very little ticking sound but its not that loud. I don't know if everything relates to one thing but could someone help me out? Thanks!

 

I think you fell victim to the wonderful 0331 head...
Start saving up some money.

 

Whats that? I'm scared to ask how much it'll cost to fix.

 

A bad head casting on the newer cherokees. It cracks in the middle.
Check your oil, is it milky?

 

I'm not sure I just changed it, how much could this cost me? Is it bad to drive around? I havan't had any problems with it running.

 

Well hold on it might not be a cracked head. Liquid in the exhaust is normal, water is one of the byproducts of combustion. As well, the cast has an imperfection inbetween cylinders 3 and 4 not around 6 and 1 so my suggestion is to try other things before just assuming its a cracked head. Besides, bad heads don't just happn ***** nilly!
Did your Jeep overheat recently?

 

nope it never goes over 210

 

K well all the misfiring could be because of a distributor, rotor, wires, ignition coil wire to dizzy wire, ignition coil. ticking noise could be a bad rotor. Just try changing the dist and rotor, maybe if your feeling up to it the wires and ignition coil wire too. they're available pretty much EVERYWHERE and cost is cheap, easy to install etc.
I personally don't think it's a bad head, my coolant level very slowly gets a little bit lower every month, and it only gets to the add line after maybe 10 or 12 months of not filling it.
Anyway, food for thought, if anyone disagrees with me than it's just progress

Ticking noise could be dizzy/rotor

 

Pick up a coolant flush kit $15 it is well worth it and change your coolant agian if it turns brown after that you`ll know it`s serious...