peobryant

Hello gentlemen, I've been enjoying my Cherokee for a few months now and an issue has just recently cropped up.

When I'm driving and the fan is in the off position, I get a fairly steady stream of smoke out of the vents closest to the window (both driver and passenger side) and I have noticed that the middle of the windshield will fog up quite a bit when the conditions are right. Does that sound like a heater core or something else?

While I'm at it, I plan on doing a tune up in the next week or so. What oil and spark plugs do you all recommend?

Thanks for all advice,

Parker

Morat

How's your coolant level?

toasterknight

Champion plugs and a diesel oil like delo 400 xle 10w-30.

InitialForce

Most likely heater core. Like Morat said, check your coolant level (both overflow and radiator). If you have a broken core you will be loosing coolent pretty consitent.

X2 champion plugs. OEM copper, none of that platinum crap.
I run Royal purple HMX but I also off road mine a lot and beat it up

toasterknight

Is that a full synthetic? What's the price premium as well?

InitialForce

It's high milage formula with extra zinc/phosphorus and a better detergent package. Full synthetic, i run 10w30. I buy it online and it's costing me the same as mobile 1 full synthetic. Each there own, I like it a lot. Noticeable smoother idle and quiter top end on cold starts and a lot smoother at high rpms. Also ever since I switched my oil pressure is higher at idle on hot days then it used to be on the same weight mobile 1

peobryant

Thanks for the replies so far, I checked the coolant level when I first noticed the issue and it seemed normal but I'll check again in the morning to see what it looks like.

Just ordered a set of 6 Champion RC12ECC spark plugs, a spark plug gauge gap tool (this Jeep is my first gasser, I've never needed one until now) Mopar oil filter and Rotella T5 10W-30 oil. I've had a bit of a stumble occasionally at idle so I'm hoping this little tune up fixes that as well.

extrashaky

Is it smoke, or is it water vapor? How does it smell? Are you smelling coolant inside the vehicle? You can put a paper towel over the vent to catch some of it to see if it's smoke or water. Water will leave it wet, while smoke will leave particles.

The fact that your windshield is fogging would likely indicate that it's water vapor, in which case it probably is a leaking heater core. The dash has to come out to replace it, or you can just bypass it in the short term if you can't tackle that job immediately.

If it's actually smoke, I would be a bit alarmed, since it would indicate that something in your ventilation system is trying to burn.

jen5

I've had this problem off and on as well. I was convinced it was the heater core from reading up on it. But I replaced my valve cover gasket and it stopped spewing fog for about a month, now it is back. Still heater core? Or maybe just the many oil leaks and a hole in the vent system somewhere? Still new and learning as I go here...