225 V6 burning, leaking or losing oil somewhere....

I thought I'd give this a run by you all to see what you think...my oddfire has great compression..161-165psi, less than 5 psi variation between cylinders, great vacuum (22hg) and runs well now that the carb is figured out. It leaks a little from the rear main and the front seal, but not enough to really wet things other than around the seals and run a bit down onto the pan. Nothing blowing back onto the axle or under the jeep to speak of. The plugs are clean, no oil fouling at all. I checked the oil after a trip to New Jersey (about 3 hours of high rpm highway driving) (4.10 gears, SM465 1:1 4th gear, 31" tires) and it was about a quart and a quarter down. I use 15w40 Rotella oil. By there being hardly any splatter under jeep, I don't see it leaking all of that, so I'm guessing it may have burned it. I'd think it would be on the plugs, but they are a light grey brown, and the compression is great when hot or cold in all cylinders. I didn't do a leakdown test yet. Do these little engines burn a bit of oil at high rpms or am I in for a rebuild, or swap?

 

I don't know if it matters, but I have a relatively new PCV valve and the hose runs into the holley truck avenger carb port on the right front.

 

I was going to ask about the pcv valve but you answered that. Is the other side properly vented? Proper splash shield below the pcv valve? The only time I burned any oil in my van or in the motorhome, I was using Rotella. You might try another diesel oil.

 

X2 on the splash shield. When you pull out the PCV valve you should not see the rocker shaft or arm. There should be a piece of sheet metal there. Different oil is a lot cheaper than a rebuild too. Try it.

 

I know this engine had been sitting a while, and I never changed the valve seals. I was wondering if that could possibly be a problem to look at as well. I will be checking on the baffle in the valve cover, changing the pcv to a new one, even though it is almost new and will try some different oil.

 

No smoke that I see at start up. No smoke when driving. Upon revving the engine to high RPM and decelerating, there is a very slight (very very) slight bit of haze, but you must be in the right light to see it, its so slight.

 

What does the inside of the tail pipe look like?

 

Tailpipe looks clean, no real buildup of anything, not oily at all, just a little carbon. No flakes, just like flat black spray paint. I am wondering if it is just somehow leaking it but it's not being blown onto the rear axle or body.

 

How bad is your blow-by? Pull the oil cap while it's running. If there is a steady cloud of oil vapor coming out, that might be it. Your PCV system sucks up this atomized oil vapor and burns it so efficiently you might not see smoke.

 

How about when you coast down a long hill, then hit the gas?

 

I reread my post, my compression isn't 161-165. It is 121-125. Sorry, my mind must've been on something else. No smoke after coasting down long hill. No stream of smoke out of oil fill cap. Small amount of smoke out of pcv grommet when pcv is pulled out and run with engine hot after running 45 minutes on highway.

 

The trip was 175 miles to Jersey, and a full day long trip of Jeeping the Pine Barrens. The last oil change was around 200 miles prior to the Jersey trip and was full. After looking at my compression numbers, I am not too confident in the condition of the rings. I am pretty stumped at the great vacuum reading however, usually it wouldn't be that good with a worn engine. The engine is spotless inside the valve covers. I'm thinking that once I rebuild the International engine I have on the stand this week, I will pull the little 225 down and freshen it up. Looks like parts are reasonable for it, at least compared to my IH truck engines.

 

Mine uses oil an I am 90% sure its valve guide seals.Good compression has nothing to do with oil rings.

 

Don't fix it if it ain't broke. Oil is way cheaper than a rebuild.

 

I changed the PCV, got a new one from NAPA. It seems to not be using any oil now. Funny thing is, the old one was less than a year old, it still rattled. Oh well, problem solved for now. It did get me thinking about rebuild of the little Dauntless. I will probably just freshen it up with new rings and bearings, maybe cut the heads for valve seals and hardened valve seats, but I seem to be reading a lot of ppl online complaining about weak connecting rods. I don't race it or mud bog it, but are the rods something I should change to a 231 oddfire rod? Should I just get the original rods checked and call it good? I had one of these engines before in a Commando as a kid. I bought it from the junkyard where I worked after school and beat the hell out of it for a few years and the little V6 never threw a rod, and I drove that one a lot harder than I drive now. I never remember working on it much other than plugs and points. If I do go through it, I'd like to address the weak links. Nothing fancy, just preventing down the road problems.

 

I have not heard about weak rods for a stock engine, but I am a novice. I have seen plenty of crushed/dished lifters and round cams though.