Blue Smoke and Oil Consumption, but only after idling or slow driving not freeway

[FnFilthy]

Let me start off with the fact it's a high mile 1992 7.3 (380,000 miles) and I'm contemplating just replacing the engine so I'm a little more confident about long trips.

The motor will puff oil smoke at start up and for a while until it "Clears Out". If I am in stop and go traffic, it loads up and produces smoke ONLY on medium to hard acceleration (but not while idling, only if I get on the pedal). If I get on the freeway and drive for a minute or so, its completely clear. If I then get stuck in traffic or return to town with stop and go traffic and periods of idling, the smoke returns.

Its definitely oil smoke, and not fuel or water. I'm going to check the intake and pull the CDR and clean it up, but if it's rings, it seems like I should see similar smoke blowing under hard acceleration or when climbing hills. During those times, if I have been on the freeway, there is nothing more than the usual light amount of carbon black coming out.

 

[Hydro-idi]

Sounds like your engine is getting worn out. Likely your valve stem seals are shot along with piston rings with that kind of mileage, which would explain excessive oil consumption & blue smoke.
But hey, if it ain't broke and the smoke doesn't bother you, keep driving it. Your engine will likely go many more miles before kicking the bucket.

 

[Greg5OH]

it is blue smoke you are seeing on medium acceleration correct?
Done a compression and leak down check to confirm?

 

[mbolton1990]

Check out that CDR, check for blow-by as well..

 

[FnFilthy]

I wanted to thank everyone. I've bit the bullet and purchased a reman from Promar (I've heard the good, bad, and ugly about them). The issue I have is that this is a daily driver and I don't have time to do a tear down and rebuild so I am hoping that I get the good roll of the dice and have a decent lump from them.
Before installing, I'm going to put in a new CDR and manual glow plugs. I've even looked at throwing a Banks kit on it, but honestly, even with the worn out 7.3 naturally aspirated motor, I haven't had any issue pulling grades.
So... wish me luck. I'll report back on the new motor. I will be installing it during Christmas break.

 

[laserjock]

Several guys here have had good luck with them. I'm hoping so too. Planning first smoke around Christmas too. It's a bigger job than you realize bythe time you strip the old block to dress the new long block. If you take your time and clean everything up good it's a non-trivial effort.

Good luck. Report back.

 

[FnFilthy]

Have no doubt, we are getting a commercial steam clean next week on the engine and tranny. I have no desire to deal with gunk. I'm way past 18!
Thanks for the support and I will update as I complete the work.

 

[laserjock]

By the way, if you call them and talk to them, and supply the parts, they will do custom work too. I had a torque typ4 cam, comp valve springs and head studs installed for the cost of the parts and shipping them to NJ.

 

[FnFilthy]

Here she is! Brand spanking New(ly rebuilt) 7.3 IDI. Work starts the day after Christmas. Already have had engine, engine bay, transmission and undercarriage steam cleaned so I have a slightly more hospitable working area.

Anyone have any view or advice on pre-oilers or such? I used to use an old distributor shaft on gas motors to run the pump up, but obviously that doesn't fly here.

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[riphip]

Rebuilder should have assembly lube on all moving parts.
Use Zinc enriched oil or Zinc additive for break in lube.

Rick

 

[Hydro-idi]

Really no need to run a special oil in these engines. We run hydraulic lifters which do not require increased zinc & a break in period.
Before you start engine for the first time, hook up a mechanical oil pressure gauge. Then pull out glowplugs. This will "free spin" engine without putting excessive strain on starter. Crank engine over until engine gains oil pressure on gauge. You have now primed engine & are ready to fire it up after re-installing glowplugs.