Okay so let me begin by saying about 2 months ago, the Jeep would overheat on stops or idle. It turned out to be the radiator however, I replaced the radiator the clutch fan and the thermostat. It was good for a few weeks and not overheating anymore, and exactly 3 weeks later it started to overheat again. Only on idle or stops or red lights. I went back to my mechanic and we switched out the radiator cap with an OEM one. This was more than a month ago, it has been good, no weird noises no overheating at all, the oil pressure is good, the coolant level never goes over 210. However the other day when I popped the hood open to clean up, I noticed that the reservoir level for the coolant was low, really low. We had topped it up when replacing the cap, so it was definitely weird when I found this out. I am not sure where the coolant is going, I don't have any symptoms of a cracked head or blow head gasket, main symptoms I'm talking about are coolant in oil, changed oil yesterday, we didn't notice anything. It looked normal, I am not getting any misfires or check engine lights. No smoke. The engine sounds are runs normal. I have no external leaks through the exhaust, no overheating under the hood, no bubble formations in the radiator and the oil is not milky. Where the hell could my coolant be going and what should I do?
Help with 2000 Wrangler 4.0 coolant issue
- Thread starter ObedaTJ
- Start date
1. You still had air in the system and it's now worked it's way out. Fill it and run it and see if it drops again.
2. It's leaking somewhere.
3. Bad head / head gasket and it's going into a cylinder and exiting your exhaust pipe.
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2. It's leaking somewhere.
3. Bad head / head gasket and it's going into a cylinder and exiting your exhaust pipe.
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mikalcarbine
Member
I've said this before in your other threads, but you really need to get your engine oil tested for coolant. Don't you want to know for sure? Send an oil sample to Blackstone, or have your mechanic do a simple test. The symptoms of a cracked 0331 head can be very subtle, and the oil often does not show signs of contamination early on.
If you rule out the cracked head, then we can troubleshoot other possibilities. Hopefully your head is fine, but that model year is notorious for cracking, so confirming that needs to be your No. 1 priority.
If you rule out the cracked head, then we can troubleshoot other possibilities. Hopefully your head is fine, but that model year is notorious for cracking, so confirming that needs to be your No. 1 priority.
I had a cracked head for over 3 years. It was a small crack. Never overheated just ran the coolant low all the time. Drove it fine until the day i traded it in. It was a 04 sport.
It is defiantly a very real possibility that your head is cracked. If u do a head gasket check the head. If the casting is the 0331 replace it
My coolant never was milky and it never made my oil smell like coolant. But there was a constant coolant smell under the hood. I did a New oem heater core new radiator thermostat hoses water pump and gaskets. Flushed the block and changed over to green. Still lost coolant weekly
Drove it for 40k miles like that
Reason i never fixed mine is because i was afraid the engine was all warped because it was obviously leaking forever and i had planned to do a full engine swap when needed. Found something else i wanted and so i traded it in
It is defiantly a very real possibility that your head is cracked. If u do a head gasket check the head. If the casting is the 0331 replace it
My coolant never was milky and it never made my oil smell like coolant. But there was a constant coolant smell under the hood. I did a New oem heater core new radiator thermostat hoses water pump and gaskets. Flushed the block and changed over to green. Still lost coolant weekly
Drove it for 40k miles like that
Reason i never fixed mine is because i was afraid the engine was all warped because it was obviously leaking forever and i had planned to do a full engine swap when needed. Found something else i wanted and so i traded it in
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I've told you before. Click through the Amazon banner and buy a kit to detect combustion gasses in your coolant. These are the symptoms of a cracked head. Hopefully I'm wrong, but it sounds like you never ruled it out, and you're still having problems. I hope you found a new mechanic at least. Best of luck to you.
Is your water pump leaking? You replaced the whole system but that one critical piece. They have a weep hole in them that causes them to leak when the bearings wear out. Look up at it from the floor with the engine running. Might need a flashlight. See if its dripping.
It could be just the head gasket and not the head. If your loosing coolant, it probably going into a cylinder and burning up and going out the pipe, as in Superduty's #3 above. It's cold in the mornings now, and when you first fire it up, you can see the exhaust steam until the engine warms up, correct? If it's #3 above, yours will show the exhaust steam for longer than normal and at warmer temps than normal. because of the additional coolant moisture in the exhaust. Or you can get a compression test done and see if your loosing compression in one or more cylinders, I would recommend a compression test.
I’ve got a new mechanic and he seems knowledged but they are telling me to open up the engine valve and check if it’s a gasket or the head would cost me as much as just replacing the gasket or head. I’m not sure I want to open it just yet
ALSO GUYS FORGOT TO ADD MY ENGINE IS NOT OVERHEATING, YES THERE IS LOW COOLANT BUT IT HASN'T OVERHEATED IN ABOUT 2 MONTHS. And no the water pump was not replaced.
Do the used oil analysis. You can get some amazing insight into what's going on in an engine from the contaminants that build up in the oil.
As @bromel said, check these guys out: https://www.blackstone-labs.com/
That's a cheap and easy way to get more insight without having to open things up.
If theres a hairline crack it will not necessarily overheat. Mine never did in 40k+ miles
Okay so I took your advice guys and went to the mechanic, we did a coolant test and an oil pressure test. Both were good, my mechanic even said it could have just been air. No leaks anywhere not even in the oil. Topped of the coolant and if it happens again, we’re going to open the engine up.
Did you check the old oil or the freshly changed oil? Did you do a pressure test for the radiator? That should rule out a head gasket, at least. Another way is to start the engine cold with the radiator cap off. If you see any spraying, you likely have a blown gasket.
Hopefully your problems go away now. I have a 2000 and am paranoid about coolant loss, so I'm rooting for you. Water pump is another possibility—yours is getting old—so check the weep hole. Freeze plugs can leak too.
Hopefully your problems go away now. I have a 2000 and am paranoid about coolant loss, so I'm rooting for you. Water pump is another possibility—yours is getting old—so check the weep hole. Freeze plugs can leak too.
For some reason he still had my old oil lol but I changed it yesterday, besides the fact that the old oil was black and almost burned it wasn’t abnormal. Both came back as fine. But we can’t rule out a cracked head just yet (according to him) but we did rule out a blown head gasket. And yes the coolant test was performed on the radiator and it was good. It could be a water pump but I doubt it just because I don’t see any leaks at all. I park the Jeep inside and it has never leaked.
I do this almost every drive haha, never noticed anything even close to that. I hope it’s a good sign