I just pulled off my 87 6.9 idi first gen banks turbo air box and noticed oil inside the intake manifold. See pic. That cant be normal? U can see a little puddle at the part inside the intake.

BTW, Redoing my return lines to fix two leaking caps at the injectors.

 

That looks pretty minimal to me, your always going to have some oil in the intake with the CDR.

 

This^

As the blowby increases you get more and more oil, perfectly normal for the design. Some people have done a road draft tube but the volume of crankcase gasses will haze out your truck and put oil droplets on everything.

 

Good Valve guide Lubrication system

 

Copy that good to know. Should i eliminate the return line to the filter? I heard that could be done, can it?

 

I would not advise it... it is part of how the system self Primes, the Schrader Valve is only on the inlet side of the Filter, it does not bleed air out of the Filter.

Replacing that line with a Clear line is not a bad thing to do..and IF you have the old style head that only has the orifice then adding a Check Valve is also not a bad idea.

 

Understood. I also noticed no air separator anywhere. Do these idi's not need them?

 

Any diesel, CDR, road draft tube or whatever will have an oily intake area. It's the result of no throttle plates, therefore no intake vacuum like a gas engine.

 

Correction, meant to say "no deisel/water separator".

 

it's all part of the Filter ... older ones had a separator mounted on the fire wall near the brake booster.




some folks get rid of the Drain Bowl and just use a Screw on Filter that has it's own bowl and drain.
you can always add aftermarket filter/separators too.

 

I dont have the filter/separator combo. I will check the firewall but I dont remember anything resembling fuel lines going the the firewall.

 

IF you are just using the FD-811 style fuel filters Then I suggest you install a Clone Racor at least.
Or change that filter to a Combination Filter/water separator Type..... Personally I would just Opt for adding the Racor they are less than 30 bux on FleaBay and you can use OEM Racor elements with them IF you wish.

 

I helped tear down a dt466e for parts, it had a road draft tube. The intake, intercooler pipes, were spotless..
Only had 176,xxx miles on it

 

That's odd, we maintained a fleet of DT 466s and overhauled quite a few, pipes were clean but inside the intake manifolds were typical diesel----- black oily gunk.

 

I drove a 95 International 1900 and something model, Plow, sander with Bitch Tank.
5 spd 2 spd air shift Diff. Drove that truck for 150K miles before I retired.
last year that was mechanical before they put the computer crap on them.
great running truck, drove it for 10 yrs.

One thing I remember, after an engine oil change, the oil stayed clean for quite a while
before it started to turn a dark color.
Don`t remember if it had a road draft tube or not.

My Mercedes Diesels depending on the years and model, some piped it straight into the
intake manifold, later into the air cleaner to collect and condense to run through a tube
back to the oil pan, and rest sucked into the intake. there was always some oil in the turbo.
A lot of people think it will damage the turbo with the droplets hitting the vanes.
There was usually eventually an oily mess in the filter area or drain pipes.

Some rig up some sort of oil catch can to collect the oil. All engines have blow by, and the
pressures it created in the crank case has to come out, either to the atmosphere, or sucked
into the engine and burned. There is really no way around it.

A new guy comes along and buys one of these old IDI`s, probably in the 200K mile range
and think the engine needs an over haul. It`s just a normal old diesel, that`s just the way it is.
A lot of them made it this far 2 - 300K miles and farther.
My 86 is almost to 304K, does it have blow by? IDK, I just drive it.

Throw the Air Cleaner back on and drive it.

Charlie