steam in exhaust

[cgflightmech]

I have been reading all of the threads on this topic, but I still want to ask. I have a 95 XJ with a 4.0 HO. It has 130,000 miles on it. I have a crack in my exhaust manifold which I am going to remove and weld this week. While I am doing this I am going to replace my head gasket and valve cover gasket. I am doing this because I just realized the white vapor coming from my exhaust. She doesn't overheat, and the coolant is clean. I guess my question is: Am I over-reacting or is this just good preventative maintenence?

[beav350]

Check to see if the oil is clean too. That's the first thing to look for. If you've ever blown a head gasket then you'll know to compulsively look for water bubbles/coffee color on the oil dipstick. Check for equal compression across all cylinders, that's also a biggie. Then decide.

[Yucca-Man]

White vapor coming from your exhaust...you live in Kodiak Alaska...and I bet that it's humid there (and cold). Sounds pretty normal so far but that cracked exhaust manifold does need to be taken care of. Are you getting an excessively high amount of steam compared to other vehicles around you?

[cgflightmech]

Thank you for the replies so far. Oil color looks normal and I will check the compression.

You are dead on about Kodiak. It is very moist and cold this time of year. I haven't paid to much attention to the other vehicles aroun here because there are a lot of junkers driving around, but I will compare.

Thanks again

[Dr. Dyno]

I have been reading all of the threads on this topic, but I still want to ask. I have a 95 XJ with a 4.0 HO. It has 130,000 miles on it. I have a crack in my exhaust manifold which I am going to remove and weld this week. While I am doing this I am going to replace my head gasket and valve cover gasket. I am doing this because I just realized the white vapor coming from my exhaust. She doesn't overheat, and the coolant is clean. I guess my question is: Am I over-reacting or is this just good preventative maintenence?

Unless your coolant level is dropping or you're finding coolant in the oil (chocolate mikshake), it's most likely that the steam from the exhaust is a normal phenomenon because you're living on cold, damp conditions.

[dizzymac]

I live in New Hampshire.....gets mighty cold here too...I always have "steam" in the winter...my temp never gets much above 160 degrees...so seeing the steam doesn't worry me....have 173k on my Xj but eng. runs ok....no leaks form the head....just the atmospheric conditions causing the steam. I do need to change thermo......makes for a chilly ride to work. good luck.

[RichP]

The steam is normal in cold weather, after running it when the exhaust system is hot the cold wet air condenses in the exhaust system. When you start it up the hot exhaust gases start to vaporize the water that is in there and result is steam. After warm up if the air is really cold and moist you will also get condensation right at the back of the tailpipe, just look at a pic of cars ideling in traffic in NYC.
Stick your nose by the exhaust and sniff it for anti-freeze, if you have a leak you will smell the prestone right away. No anti-freeze smell 99.9% of the time means no leak.
If you do alot of short cycle type driving, limited warm up and never let the moisture in the exhaust cook off you may rust the system out early.
On the oil side if you don't run it for say at least 30 minutes the oil never reaches the operating temp of the motor, result is that the moisture that condenses in the engine, just like the exhaust system, never has the opportunity to cook off or boil off, that will generally leave a light brown or tan residue on the inside of your oil filler cap and if it gets bad enough it will also show up on your dipstick as a brown mix on the highest point of the dipstick.
Here in PA on a cold morning it takes about 9-12 minutes for the thermostat to open and the gauge to reach operating temp, if you stop at that point and shut the motor off, pull the dipstick and feel the oil you will find that it is still not hot, warm maybe, but not hot enough to boil off the moisture, that generally takes about 30+ min to reach that temp and start cooking it off, then it is a matter of how long you drive it that determines how much moisture gets cooked off.

[cgflightmech]

thank you all for the help

RichP and dizzymac thank you for the replies. I do indeed smell prestone. I changed the head gasket, and some other things and it is running beautifully. I don't know if this is close to you guys but I grew up in Bucks county, PA and My parents now reside in HOLLIS, NH


thanks again


semper paratus

greg

[cgflightmech]

I am a U.S. Coast Guard rescue aircrewman and flight mechanic stationed in Kodiak , AK. I fly on HH 65 dolphins

[jayeepxj]

that one cracked me up

sweet

[dizzymac]

Glad you found the prob., sniffed my exhaust too, it's OK. I'm about an hour or so from Hollis. Good luck and thanks for serving out country. Army68/72