Smoking XJ

Ok, here is the deal. I started up my XJ last night, and smoke started to come out of the exhaust pipe at a fairly steady rate. My friend was behind the Jeep when I started it and he said there was alot of black smoke at the beginning that changed to white smoke. I got out to look and there was alot of water coming out and the smoke would dissipate fairly quickly. All I saw was white smoke, so I think it is steam, but it smelled like the engine was running extremely rich. I turned it off and went about my business, figuring that if it was infact running rich it wasn't really a big problem at the moment. The next morning I went out to drive my Jeep, and when I started it up I got more white smoke, except this time there wasn't the smell of gas. I let it idle for a while, and after about five minutes of running the smoke went away. The engine ran fine, and doesn't idle funny at all. But, a few nights ago I was driving around and came to a stop. When I tried to accelerate my engine sounded like it was bogging down and then it died. When I tried to start it, it wouldn't start unless it was at WOT. Any ideas on where this smoke is coming from and why my engine would suddenly bog down and die, but then run fine after I got it started?

Check your back window, if there is a film on it, check it. Sounds like a blown head gasket and you are sucking antifreeze into the engine and burning it.

That is really not what I want to hear. How expensive do you think it will be to replace the head gasket?

Depends, it's a $35 part about, 3 hours to do it yourself but it depends on how much damage you did running it like that. You also need to be sure it is the gasket, could be a cracked block or head. That really can't be checked till the head is off as far as I know.

I am beginning to wonder if I am over reacting to this steam. It was raining outside so perhaps nothing is wrong except the usual H20 that is produced through combustion can't dissipate in the air as fast at usual. I don't seem to be loosing any significant amount of coolant, nor is the Jeep hard to start after it has been sitting for a while (which I would think would be the case if I was leaking coolant into the cylinder). I am going to change my oil in a few minutes, so I will have a better understanding of what is going on afterwords. If I have coolant in my oil then I'm fawked, if I don't I will atleast know that there isn't any coolant leaking there. I'll post back in a few hours.

I have seen several head gaskets blown in my day. And you have the exact symptoms of one.
Sorry bout that. Its a real PITA sometimes.
Check your motor oil for coolant in it.

Maybe you missed what Tom was saying about the blown head gasket. He said it could be burning coolant, which in that case it may not show up in the oil. I have seen blown head gaskets that burn the antifreeze, and it is not visable in the oil. Like he said the total cost to fix can vary alot, from the cost of the gasket and labor, to a new block or head. I know this is not what any one wants to here, But I thought I should point it out sense you said you were checking your oil for coolant. Good luck, hopefully it's not as bad as it could be.
P.S. If I had to guess why your jeep smoked black smoke, then changed to white I would guess that the black smoke could be the motor running rich on start up or it is oil burning, maybe caused by bad valve guide seals, then the oil was burnt leaving the burning antifreze to show.

Ok, the oil was coolent free. I am still a little sceptical about having a blown head gasket. The reason I am skeptical is because the exhaust smells the same as it always does, and there is no smoke at all when either the Jeep is warm or it isn't raining outside. The steam doesn't smell like antifreeze, and the volume of steam coming out is so great that I can't possibly think that the engine would run as well as it does if it had a coolent leak of this magnitude. The engine idles fine, and doesn't have any power loss from what I can tell. I could just be talking myself down, but I really don't think there is a problem anymore. If I had a blown head gasket wouldn't it steam rain or shine?

You are probable right. If it only steams when it is very humid it could just be the condesation in the exhaust. I realy hope this is the case!

Hope your right but...as someone mentioned you could have a leak in which the water and oil do NOT meet. A little is going to make a lot of steam and will be much more visible on damp and/or cool days. If it is a bad gasket/cracked head ignoring it can be bad. Get a compression and leakdown test done.

Sarge

Look at the plugs, look for any that are 'different' from the others.

<Sarge echo on> Get a compression test and a leakdown test. Stop guessing. <Sarge echo off>

Sounds like a bad case of Blow-By to me.


I had this happen out on the trails. XJ was on a tilt for like 10min on some rocks. Oil got sucked into the air filter fromt he CCV, atomizing into the TB and....Boom... Smoke centural!

Clean valve cover, clean hoses, gromets, etc., and reassemble.

Sarge said:

Hope your right but...as someone mentioned you could have a leak in which the water and oil do NOT meet. A little is going to make a lot of steam and will be much more visible on damp and/or cool days. If it is a bad gasket/cracked head ignoring it can be bad. Get a compression and leakdown test done.
Sarge

Click to expand...

Agree.
You can also get the cooling system pressure tested to see if any coolant is going into the combustion chambers. Check the plugs. Do they all look the same or are there one or two that have coolant stains?

I had coolant leaking into a cylinder (5), it was a sometimes thing. Noticed it would overheat on occasion, was loosing some coolant (but not a lot), noticed some foaming/bubbles of the coolant in the surge tank (in your case probably at the rad cap). Plug was kind of rust colored (the others were dark grey). Hung a white rag in front of the exhaust, moisture left kind of a coolant colored stain (green in my case).
The leak would start and stop, randomly. Finally cleaned the inards out of a spark plug (broke of the top, drilled out the insides), silver soldered a tire valve on the end. Ran each cylinder up to top of the compression stroke and ran 15-20 PSI in there, noticed a few bubbles in the coolant, removed the thermostat and noticed a whole bunch of bubbles in the coolant, when I hit the right cylinder.
If your gonna push air into the cylinder, find some way to hold the harmonic balancer, doesn´t take much pressure to turn the motor over a bit, especially with all the plugs out.
Also found a valve (intake) that looked like an inside out mushroom, a little too much fluid in a cylinder can have catasrophic consequences, just cost me a valve, could have been a whole lot worse.

Not to be redundant but a compression test is far cheaper than a new head, engine or even gasket. Plus you will have peace of mind.

Where can I get a compression test done?

Rather than pay somebody to do it for you, go to your favorite auto parts store and buy a compression test guage. It's very easy to use, comes with instructions. $24.99 at AutoZone. You'll have a new toy in your box from now on.

This, a vacuum guage and a DVM are essentials and none are very expensive.

Dvm?

Osprey413 said:

Dvm?

Click to expand...

Digital Volt Meter, worthwhile to invest in a decent one cause it can be used around the house too. Simpson, Beckman, fluke all make good ones though a cheaper one will work OK. Figure ~$50 for baseline decent...