Coolant vapor 'smoke' pouring out of exhaust manifold

[jamesbeat]

Making a new thread, because I think my P0177 code was merely a symptom of a much worse problem.

I initially thought I wasn't losing coolant, but it appears I was - I was looking at the 'cold fill' line when the engine was warm.

I swapped out the temperature sensor and topped up the coolant, then started the engine. What appears to be vaporized coolant immediately started spewing out somewhere in the area of the exhaust manifold, or at least that's what it looks like to my untrained eye. It's towards the bottom of the engine on the passenger side.

I did spill a lot of coolant while changing the sensor, because I didn't think to drain the coolant first, so it's possible that a bunch of coolant got on the exhaust manifold. Honeslty though, I wouldn't have expected it to start vaporizing the instant I started the cold engine if that was the case.

Is this the head gasket? Why would the smoke be coming out of the manifold rather than making its way to the tailpipe?

By the way, there is no milkshake on my dipstick, but I know that doesn't always happen with a bad head gasket.

 

[turblediesel]

Water pump going bad? Coolant getting past the seal and coming out the weep hole?

 

[jamesbeat]

Would that then collect on the exhaust and vaporize?

 

[jamesbeat]

I think I may have just spilled coolant on the exhaust manifold, because when I started it up today, there was no vapor coming from the engine bay whatsoever.
The tailpipe is still blowing clouds of vapor, but looking around, all the other cars around here are doing the same thing. It's REALLY cold here in WI right now.

 

[duderz7]

Check your hoses that connect to the overflow tank, if they leak it could go right on the manifold. Sounds like it's all good, but checking hoses is easy and could save you major headaches.

 

[jamesbeat]

Good idea, thanks.
I must be losing coolant from somewhere. I had to top it up with about 8 oz to get it back to the cold fill line, and I'm ashamed to say I don't know whether that happened suddenly, or slowly over the year I have owned the Jeep. I guess I'll just keep an eye on it and see what happens.

A complete cooling system overhaul was the next major maintenance job I had planned for when the weather gets warmer anyway.

 

[turblediesel]

Would that then collect on the exhaust and vaporize?

It can. Any little pools would take time to vaporise or evaporate.

Cooling systems take awhile to burp air out of the system and from what I've read here it seems the 3.7 is fussier than average.

 

[lfhoward]

Water pump going bad? Coolant getting past the seal and coming out the weep hole?

I’ve had this happen to me with two different water pumps over the years. The coolant slowly disappeared, and I was worried about head gaskets, but it turned out to be a simple and relatively inexpensive fix both times.

 

[jamesbeat]

It can. Any little pools would take time to vaporise or evaporate.

Cooling systems take awhile to burp air out of the system and from what I've read here it seems the 3.7 is fussier than average.

Yes, I'm keeping a close eye on the coolant level so I can top it up if it burps out some air.
I did use the bleed screw after changing the sensor and topping the coolant back up though, so I'm hoping that would have taken care of most of it.

 

[jamesbeat]

I’ve had this happen to me with two different water pumps over the years. The coolant slowly disappeared, and I was worried about head gaskets, but it turned out to be a simple and relatively inexpensive fix both times.

I dropped the ball here somewhat. My coolant was below the 'cold fill' line when I bought the Jeep about a year ago, but I had put off topping it up. This was because i previously had a 2003 Liberty, and inadvertently put in the wrong coolant (I added HOAT but the coolant that was already in it was the green stuff).

I couldn't tell what was in the reservoir of my current Jeep, so I decided it was safer to temporarily leave it a bit low than risk putting the wrong stuff in. I planned to completely overhaul the cooling system anyway, so I thought it would be ok until then.
Unfortunately, I then had some trouble with chassis components, so the cooling system had to wait while I figured that out.

Now I am in the stupid position that I don't know how fast my coolant has been depleting. It has lost about 16 oz over the course of the year that I have owned it, but I don't know whether that happened gradually over a year, or suddenly in the last couple of days.

I'm just going to drive it cautiously and keep a close eye on the coolant level. My problem now is that, should the level go down, I won't know whether it was because I'm losing coolant, or if it's just trapped air making its way out of the system.

Part of my plan when I overhaul the cooling system is to change the water pump. It looks like it hasn't ever been changed, so I might as well do it. They aren't all that expensive, and it's easy to get to.