AFMan

I've used a whole bottle of coolant in the last month. I'm not getting any coolant lights, I've just noticed I have to fill it. I looked in the oil, and it doesn't appear to be any coolant, from a cracked head, but I'm wondering where it is going. Any thoughts? I have posted on here a periodic cylinder 6 misfire, but I have not noticed any misfire at all. I guess I'm wondering, if possibly the coolant is running into the engine, via a cracked head, and causing that check engine light? Thanks everyone.

epic.jeeper

Have you changed your oil? i just had the same problem. I changed the oil and got a nice watery surprise in the oil catch pan. The coolant will settle to bottom, use something clear to drain the oil into. do you have a pin hole leak in one of you hoses?

SeriousOffroad

Turn on your heat and take a big sniff. Does it smell sticky/sweet? Leak in the heater core.

Check your tranny fluid. Remember that your tranny cooler is in the radiator, and if either one is leaking......

epic.jeeper

You only have a tranny cooler if you have the factory towing package right frankz? i need to install one i think

djb383

All auto trannys have a cooler inside the rad. The factory tow pkg also has an external tranny cooler in addition to the one in the rad.

1991Jeep_Man

I think they all came factory with some sort of tranny cooler.. some were just heavy duty (the towing package)

epic.jeeper

Ok, thanks guys.

zjrog

My radiator was seeping a bit, losing some coolant a bit at a time.

AFMan

Did this today, and smelled nothing sticky/sweet. Tranny fluid looks good, and no visible leaks. Confused.

TheJerm

What year is yours? mileage?

I would 1st drain your oil and look for signs of coolant (milky brownish)

Any white smoke out the tail pipe? any leaks around/under water pump, t-stat, houses or rad?

Then look under the valve cover thru the oil fill cap with a flashlight. Any light brown oil/coolant mix? alot of sludge? sludge will hide the coolant leak on top of the head and it will evaporate off before you can find it.

Onto the tests:
Compression test: if two cylinders next to each other have lower compression then its probably a blown head gaskets. They all should be within spec and relatively close to each other.

Then a leak down test to see if any cylinders arnt hold pressure aka blown head gasket, cracked head or bad rings

Also do a block sniffing to see if there are any hydrocarbons in you coolant

AFMan

2001 4x4 with 74K on it

Just poured some old oil(changed a week ago) into a clear bowl and waited almost 2 hrs, and didn't see any separation of coolant or milky brown difference.

Looked under the valve cover and don't see any coolant or sludge.

Next comes the compression test I think. I will do it and get back with everyone.

On a side note, I'm wondering if maybe my radiator is leaking or cap is bad. I need to have it tested so that and the compression test will be next.

ZeppmanR

Coolant could be getting burned/boiled. check water pump

dyte2004

check the weep hole under the water pump you have to get right under with a flash light to see good

movierooms

cracked reservoir?

AFMan

Okay, now I think I'm smelling some sticky sweet smell in the AC/Heater. I still have to fill the coolant about from the "add line," to the "Full line," about every 3-4 weeks. So, I''m confused. Please refresh my memory as to what this might be. My tranny fluid is fine, so I don't think that's it. I changed out the cap, that did nothing so I'm not leaking there. No visible leaks anywhere, and no coolant in the oil. What's next? Do I change my radiator? Please advise guys. Thx