More engine problems.

[trail rated]

So I finished replacing the cylinder head on my KJ not too long ago, I drove it gently to break it in and even used non synthetic diesel engine oil (a lot of people told me to do this).

I changed the oil about 2,000 miles ago using Valvoline Synpower and a Motorcraft FL-1A filter. Well, I checked the oil level Saturday and found that it was 2 quarts low! All I had in the garage was 5W-40 Shell Rotella synthetic diesel oil ('cause that's all my WJ gets!) so I put it in the KJ. Today, 500 miles later, I checked the oil again and it was 1 quart low!

Here is the problem, there is no smoke, the plugs look clean, and there are no leaks. I also checked the blow-by by blocking the PCV system, there was some blow-by but not more than I think would be normal.

WTF???

kopkrab.gif

 

[tjkj2002]

How's the coolant look? Could be bad valve seals,no smoke does not mean it ain't burning oil.

 

[trail rated]

How's the coolant look? Could be bad valve seals,no smoke does not mean it ain't burning oil.

The coolant and oil both look fine.

 

[kb0nly]

With the heat of the CAT's on newer vehicles like our KJ's they can sometimes burn oil and you won't really notice much out of the tailpipe, except for a slight blue hue to the exhaust if you look closely, the oil gets burnt up really good leaving little evidence. I saw a Dodge Ram doing this, burning oil but there wasn't much evidence by the exhaust, but when the shop pulled it all apart they found the CAT had evidence of burning oil inside it.

My guess is your either burning it or leaking it somewhere thats not easily noticeable? And if your not seeing oil floating in the coolant then its going somewhere. Wish i could give you better advice but i can't!

 

[kj924]

Valve seals would be my first guess....do a compression check on the cylinders to see if one or more is down on compression.

Like TJKJ said...no smoke doesn't mean no problems.

 

[trail rated]

Hmm, are the valve seals easy to replace? I mean, I don't have to pull the heads off a second time, right? My FSM doesn't show much on this.

 

[kb0nly]

Replacing a valve seal means removing the spring, but i have seen shops do this by rolling that cylinder to TDC and then using compressed air in the cylinder to keep the valve up while servicing it. It can be done without pulling the head.

Compression test sounds like the way to go at this point.

 

[tjkj2002]

Hmm, are the valve seals easy to replace? I mean, I don't have to pull the heads off a second time, right? My FSM doesn't show much on this.

Replacing the valve seals is a temp fix in most cases,90% of the time when new valve seals are needed then new valve guides are also needed.That does mean head removal and taken to a machine shop so they can press out the old ones and press in new ones.

A compression test will not show bad valve seals,it will show bad rings which is another main cause for burning oil.