Evening everyone!

So I just recently put a truck i've had over a year on the road now. '91 F350 cab/chassis, 12ft flat bed, 4x4 dually 5spd.

Truck only has 205,000km (128k miles), and by the condition of the truck, and lack of rust anywhere, I have reason to believe that.

However, it does not have it's original engine. Has an engine out of a van, I can tell by the factory timing adapter on line #4 instead of being on #1 like on trucks.

It burns an unbelievable amount of oil. Did a ~300 mile round trip last saturday with it, it ate 12L of oil! Oil is fresh, Diesel 10W30 valvoline.

Intake has little to no oil in it, so it's not CDR related, what can it be? It runs great, idles well and everthing.

I did notice rear cylinder on passenger side, liquid oil seeping out between manifold and head....

No idea on mileage on engine, it is very clean, doesn't leak or even sweat a drop of oil, just burns it all! I was thinking maybe a high idle hours engine from an ambulance or something, but even that wouldn't cause it to burn this much oil...?

Any ideas? Otherwise this engine has to come out, it smokes blue constantly, worst between 1500-1700RPM.




On side note, this is the truck. Awesome what a 60$ tremclad brush and roller paint job can do

Before


After

 

When I tore my oil guzzling 6.9 down for the rebuild, I found a combination of things. All the valves and seats were completely beat to death, and I had a couple pistons with broken rings. I would do a compression and leak down test. It was hard to believe it ran as good as it did, other than excessive oil consumption and hard starting; it still held good oil pressure. The truck looks great BTW!

 

If its smoking blue, its exhaust guides or also turbo seal if so equipped. These things are hard on guides, and my understanding is, they dont have hardened guides.

 

True, I forgot to mention that. When I took my engine to the machine shop, the the guy told me the heads were completely worn out. I ended up with everything being replaced, valves, guides, seats, seals, springs, keepers, and retainers. For money reasons, I did it in pieces. All said and done the heads cost $680, I don't think that is too bad for all that had to be done with them. You may be able to get away with just having the heads redone. Mine had over 400k on it, not wanting to take any chances I went with a full overhaul.

 

UPDATE,

So I took the drivers side valve cover off (real easy on non AC engine ) and other than slight slugging found on the valve cover, nothing out of the normal, everything is tight, valve seals all look ok from what I can see through the springs.

Unfortunately the problem is on the passenger side, as the more I drive it, the more I see oil sipping through the exhaust manifold where it meets the head. Its getting worst, just idling I see oil bubbling through the exhaust manifold gasket on the last cylinder by firewall.

I haven't had time to take everything off that side to get that valve cover off as I needed the truck all weekend.

I did do a quick compression check of all cylinders on drivers side, and that one back one leaking oil on passenger side, compression is all ok, the oil leaking one is the lowest tho at 380psi, vs. all the others around 410-420psi. Probably sticky rings now with the amount of oil going into it?

 

Keep us posted if it don't get any better. They usually don't but I'd like to see how it goes.