89 mechanical 466 smokes and fuel in oil

fourwheelinj1 · Oct 19, 2017

Recently bought an 89 international medium duty with a 466 engine with 90k miles on it. It was owned by a local small town and rarely used. It fires up instantly and runs great, but it smokes a grey/white smoke. I took an oil sample and had it analyzed. Everything looked good excepted there was fuel in the oil. I am assuming that the smoke is being caused by the fuel in the oil. Is this probably an injector problem. We changed the oil and ran the truck for a couple days around the farm and the smoked seemed to clear up. now after the truck has been sitting for a couple months the smoke seems to be back. I am sure the diesel that is in it is old so I am thinking of adding some fresh diesel and some injector cleaner to see fit helps. Thoughts?

DMiller · Oct 19, 2017

Nozzles on these engines will not put fuel in the oil unless leaking thru at the tip and filling a piston up, THAT would be noticeable on start ups.
This engine have a distributor head style injection pump or a inline? Actually either will have a transfer pump on the side where these are known to lose seals and put fuel in the oil.

Delmer · Oct 19, 2017

Yep. I'd work it a couple hours, drain the old diesel, flush the tank with new diesel or the old stuff that's settled in a bucket. Add all new diesel, and try to work it enough every time you start it up. See what it does after a couple tanks full of fuel. If you won't use up two full tanks of fuel in a reasonable time, then use a plastic boat tank instead of the stock tank, then you'll know it's clean.

Fuel in the oil is not causing the smoke. But the smoking could be causing a little fuel to get into the oil, if it's getting past the rings from running cold, and misfiring injectors.

Also, drain and change or test the coolant. Even if you just drain it into a clean bucket, and put it right back in, the condition of the sediment will tell you what you need to do.

thepumpguysc · Oct 19, 2017

Miller is on the money w/ his question.. inline or distributor??
Do the lines coming off the pump going up to the injectors, go in a circle [distrib.] or straight line [inline]?
The Ambac distributor pumps [American Bosch] were/are bad about getting some age on the seals & leaking fuel into the crankcase..
As long as she starts right up, your looking at just a reseal job.. THATS IF the pump is the culprit..
Some FRESH fuel & a good injector cleaner may be all you need??
Follow the directions on the cleaner bottle!!! TO MUCH is a BAD THING..
IF 1 is enough, then 2 is better, IS NOT THE CASE w/ injector/fuel system cleaner..
Good luck & let us know how you make out..

DB2 · Oct 19, 2017

thepumpguysc said:
Miller is on the money w/ his question.. inline or distributor??
Do the lines coming off the pump going up to the injectors, go in a circle [distrib.] or straight line [inline]?
The Ambac distributor pumps [American Bosch] were/are bad about getting some age on the seals & leaking fuel into the crankcase..
As long as she starts right up, your looking at just a reseal job.. THATS IF the pump is the culprit..
Some FRESH fuel & a good injector cleaner may be all you need??
Follow the directions on the cleaner bottle!!! TO MUCH is a BAD THING..
IF 1 is enough, then 2 is better, IS NOT THE CASE w/ injector/fuel system cleaner..
Good luck & let us know how you make out..

What injector cleaner would you recommend PSG?

Thank you

Tenwheeler · Oct 19, 2017

I would also check to see if the turbo impeller is rubbing on the housing and if it has any signs of oil in the engine air intake.
That has nothing to do with fuel in oil but can cause the smoke you describe.
If you have a Ambac also check for a restriction in the fuel return system.

Truck Shop · Oct 19, 2017

What's the temp gauge read? A cold running DT will smoke like hell and put fuel in the oil. Thermostat maybe.

Truck Shop

thepumpguysc · Oct 20, 2017

Personally I'v SEEN Lucas injector cleaner do some amazing things..
BUT theres a new one on the market from DTECH.. supposed to be "the sh*t".. ??

fourwheelinj1 · Oct 20, 2017

Not sure which pump we have so I will have to check this weekend. So if the fuel is leaking into the crankcase through the pump will just removing the transfer pump and putting in new seals in it fix it or will the entire injection pump have to be resealed. I am hoping this is something easy because we don't use the truck that much and it cranks so easy and runs great just as it is. Also is there anyway to tell if we fixed the problem without having to change the oil and re-sample after each repair attempt?

As soon as we bought the truck we changed the oil, all filters,coolant, and all belts/hoses. We sampled the oil during that change and found the fuel in oil.

Former Wrench · Oct 20, 2017

Here's a couple of things to think about. You can check for the leak by changing the oil and checking the height level. Run the truck 25-50 miles or more. Let it sit till all of the oil runs out of the block, passages, or hoses. Check the height and see where things are at. You don't want to be growing oil.
Think about the seal. Is it shot because this is an old truck and the seal got hard and failed? Or is a shaft bearing/bushing worn causing the seal to leak?

DMiller · Oct 20, 2017

Again depends if AMBAC round head or Bosch inline.

Delmer · Oct 20, 2017

You don't have to change the oil to sample it. If the level doesn't go up in two tanks of fuel, you could sample it, but a tiny amount of fuel might be left from the old oil too. Even if you know how many miles were on the old oil, it might have more hours than the miles would indicate, lots of idling time might put fuel in the oil. As long as it sounds fine, I wouldn't worry about it until you know what's going on, that is, it's "growing" oil consistently, or starts knocking on a cylinder at idle.

DMiller · Oct 21, 2017

Gonna think I am nuts, in the 'Olden days' when we suspected fuel in oil would touch the dipstick to cardboard, if spread way too quick then had a gritty/poor lubricant feel between fingers most likely fuel in the oil.

fourwheelinj1 · Oct 22, 2017

Well I looked over the truck today. The truck actually belongs to my father. He bought it at auction and the ad said it had 90k miles. I looked at it today and the odometer was hard to read but it actually says 290k miles. The truck has a decent amount of blow by but cranks and runs good. It has the inline style injection pump. I think some of the smoke you see is blow by and some is coming from the exhaust.

DMiller · Oct 23, 2017

Blowby with a cold engine will put some fuel in the oil over time. May not have a real issue here.

Tenwheeler · Oct 23, 2017

DMiller said:
Nozzles on these engines will not put fuel in the oil unless leaking thru at the tip and filling a piston up, THAT would be noticeable on start ups.
This engine have a distributor head style injection pump or a inline? Actually either will have a transfer pump on the side where these are known to lose seals and put fuel in the oil.

I beg to differ, with respect! That is possible but rare in my opinion. Injectors with poor spray patterns can flood the cylinder walls at low speeds, smoke and put fuel in oil over time. I thank it would be less expensive to pull the injectors and have them tested than jump on an inline injection pump. Yes check out the supply pump first and I hope you do not have a real issue either. Run it and see what it does like they said.

DMiller · Oct 24, 2017

Should be white smoke if fuel or over-fueled or weeping/bad tip nozzle not grey and should clear up rather quickly once running awhile building heat. Will equate to a stagger or intermittent miss as the feed to a specific cylinder would be weak due to unable to make atomization pressure as well.

Still is possible and you are correct.

fourwheelinj1 · Oct 25, 2017

I guess I will just put some fresh fuel and injector cleaner in it and try to put some miles on to see what that does first.

On a totally unrelated note there is a small tank mounted under the battery box that is coated in oily residue. It has two lines that appear to be steel braided lines up to the front of the truck/engine compartment area. I haven't been able to crawl under the truck yet to see where the lines go exactly. I know is not the air tank or the hydraulic tank for the dump so I am a little puzzled as to what it is for. Any ideas?

Tenwheeler · Oct 25, 2017

You tube Luber finer 750C. Look familiar?

89 mechanical 466 smokes and fuel in oil

fourwheelinj1

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thepumpguysc

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DB2

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Truck Shop

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fourwheelinj1

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fourwheelinj1

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