squirrelnw

okay info first
2000 xj sport
127000 miles
2nd owner, head has never been off and I just replaced the heater core. no leak inside cab at all or around new heater core.
new hoses under hood, no leaks, good radiator and again, no sign of a leak anywhere, no steam.

BAD.. smell of antifreeze under hood, suspect overflow bottle vent.. no leaks anywhere, no fluid loss or mixing in either oil or coolant.
I have noticed a weeping of fluid, ( oil ??? ) on passenger side of block between head and block that on other forums I found it mentioned this is normal. looks and smells like oil. no antifreeze there.

symptoms.. occasionally when I start it up hot it has a miss in one cylinder that clears up. no smoke or steam at tailpipe or engine compartment that I can see. have smell of antifreeze under hood but nothing at tailpipe. exhaust smells like exhaust with no antifreeze smell..

so I am looking for ideas as to where my smell may be coming from. Do you all smell antifreeze under your hood??? I noticed a vent at the top of my overflow bottle and I can smell it there but I dont want to rule out other issues. no loss of coolant, the miss worries me so I am tracking this down.
thanks

bloddy mud

no loss of oolant? if not could be getting hot and venting out of the vent you mentioned of the overflow bottle. if there is coolant loss that you have not notied you could have the famouss cracked head i been seeing with your year. any in the oil? look for a milky fluid in the oil and unexplained high fluid levels on the dipstick wait for some oun to chime in.

Tx9h6e4cuda

The miss is probably the po3030 (I think that the correct code) for miss fire #3 cylinder. This is a common problem because the fuel boils in the injectors and will cause a misfire senaro. There was a bulletin for that issue at the dealerships and they put a shield to try and keep the injector temp down. My Jeep does the same miss fire as yours and my fix will be to wrap the injectors in heat resistant tape (when I get my 748 swap done).

The antifreeze smell.....its more then likely the overflow. Try blocking the vent off to see if the smell either goes away or lessens. All the vent is for when if the engine gets nuclear hot and is purging all the fluid out of the radiator, it will go out that vent and not damage the bottle. Also its for heat to escape when it boils over.

squirrelnw

thanks cuda and bloddy, I will tape off the vent hole and see if the smell goes away, so you all have that same issue??? good to know. as for the code, I will have a code reader run on it but have thrown no codes as of yet that I can see. good to know I may be ok. just bought it and not lookin to put a bunch of money into it, I think I will still do the plug check and coolant pressure and vapor test though. just to rule things out. this site rocks for help, lots of info on here too. thanks everyone

Tx9h6e4cuda

I have the misfire senaro when its hot outside or the underhood temps are still high after shut off. Mine only had the code stored with no check engine light.

The antifreeze smell......well I always smell antifreeze because my heater core has a pin leak. I have a drivers floor pan to worry about before I fix the heater core.

squirrelnw

jeep goes in wedn to have cooling system pressure tested. I will have them check for codes to see if mine is stored too but not showing a light. in visual check they could not find any snail trails from antifreeze or leaks either. we shall see though. I do have that weeping on the passenger side of block. hopin to eliminate that as the leak point for antifreeze and hope its just all oil.. not a mix. more when I know on wedn. thanks for all the info guys. will pass it on to them.

last question. is there a hidden spot on the radiators that is known to leak but real hard to spot if its like a pin hole?? I see no leaks at the radiator anywhere but there are some hidden spots and a smell of antifreeze around it. this has been a pain to figure out. not a difficult thing to do usually. leaks a leaks a leaks. you see em pretty easily usually

tjwalker

My guess is that you have a seam on the radiator that is starting to fail. Radiator seam failure is VERY common on OEM radiators on late model XJs and they can be snaky to find at first.

I had it happen on my 99 at about 120k. HOW OLD is your radiator? Is it original? If it is, get it out of there. A cooling system pressure test should help you isolate this leak though.

I could "smell" the antifreeze under the hood on mine, but I couldn't find any coolant leaks to save my life. At first. Then the leak started and it grew quickly; luckily I was able to swap out the radiator and water pump and hoses in time to avoid a disaster.

Don't delay on resolving this. Good luck and keep us updated....we want to know the root cause of your leak.

2000xjgoldie

I had a weeping radiator right at 100,000 miles replaced it and no issues, but then I drove from Illinois to Washington State. I have since lifted and toyed my jeep, once drowning it in a creek. Filled the engine with water. Replaced the spark plugs and ran the oil thru about 4 times until it was nice and clean. Now the issue is I wil drive my jeep and the temp is perfect, no water in the oil, but after I turn the key off it leaks antifreeze. Do you think this could be my head gasket? (even though my oil isnt milky)

squirrelnw

thanks to a post above and your comments. we looked long and hard at the radiator today with a flashlight and saw some possible signs of weeping at the seems in some really *****y places to find. truck has 127k on it and I think that is it. also plugged off the overflow bottle vent today and that seemed to help some with the smell.. if I do my radiator I am gonna also do waterpump and clutchfan while I am in there. make sure I got good flow on water and air thru the system if I am that far in. I will let ya know what we find. thanks for all the support guys. I will be back to figure out which lift I want later. gettin it runnin good first.

bloddy mud

Np

squirrelnw

well as stated above. leak will be hard to find, we found it, and now that we did the bloody thing is starting to leak worse and worse. its like I found it and now it has no where to hide so its gonna leak with a vengeance. guess its time to ride the bike till sat when I change out the cooling system... thanks for your help guys. wish it had lasted till saturday, now I get wet on the bike. woot. bike needs washing anyway, rain will do that for me. .

bloddy mud

Kb weld does help. It's a temp fix until you can swap a radiator. I've done it a few times. Also if you have a plastic one you can buy a plastic epoxy and that works. There are temp fixes that will keep the Sox dry. I Kb welded one in the fall and it got me till spring with no leaks. Still wasn't leaking when I chat.fed it. Try that if money is tight