Ford 201 cid 3 cyl. Diesel exhaust soot in rebuilt engine

Ray T.

Member
I recently had my Ford 201 cid 3 cylinder Diesel engine from my 1971 Ford 4500 TLB completely rebuilt. I installed it and have it up and running and it currently has about 4 hours on the engine. I have been running it without a muffler and have noticed I am getting a bunch of small oily soot spots / freckles on the tractor hood and surrounding area.

I know diesels can be “dirty”, but is this to be expected even from a newly rebuilt engine? It may have been happening before the rebuild, but I never noticed it with the muffler on and blue smoke.

It does have new aftermarket injectors and the original untouched injector pump set at the proper timing. It starts right up even after sitting for weeks and appears to burn pretty clean without any noticeable smoke above 900 rpms. When idling below 800 rpms you do start to notice some gray smoke and roughness.

Should I be concerned with the soot or rough idle below 800 rpms?

Thanks
 
That soot and oily stuff is from idling the engine at 800 rpm with no load. Diesels run with widely variable peak gas temperatures unlike spark ignition engines. It takes a long time to warm up a diesel that"s at low idle than it does and SI engine at low idle. the low gas temperatures and the cool cylinder walls that occur at low idle doesn"t let all the fuel burn completely and you have soot and an oily substance known as "diesel slobbers" in the exhaust. I believe that"s what you are seeing.

Get your tractor out and put it under load so it comes to operating temperature and operate it like that for at least a half hour and this will clear up. Since it"s just been rebuilt, take care to break it properly.
 
As others have said, work it! Diesels have a much cooler idle exhaust temperature than gas engines do. Only way to be sure to stop wet stacking is to rebuild the engine for the highest compression heat possible, which means ALL new head valve seats to get the valves closer to flush again. Most won't spend the time or money to do that. Be aware that even a good running engine may or may not wet stack when idles again awhile after being worked hard. My IH 560 I tractor ride with wet stacked last year even though it pulled fine, but it would drip with light load cruising. So last winter I had ALL valve seats installed so the valve faces were flush to .005 above the deck. It raised the compression enough to stop it completely, as it didn't drip any this past summer in the 1850 miles of travel. One friend on the Mackinac bridge drive trip had a new to him Ford 3000 diesel, it started wet stack dripping about two hours in on the first day even though it runs well. He's used to gas, and had never seen that before. By the time we all arrived Thursday morning the black stuff was getting everywhere. WD-40 did clean it up well though..
 


Being it's a TLB it's hard to take it out and work it hard under a constant load like pulling plow or disc, but the main thing is to get some heat in the engine. If you have some work to do with it after it's warmed up a little rev the engine to 1800 rpm and leave it there while you using it. If you don't have much to do with it at the moment just rev it to 1800 rpm and let it set and run like that for 2-3 hours non stop.
We don't plow anymore so when I rebuilt my 4000 I let it run for a few hours at 1800, then when hay season started I hooked it to my mower, set it at 1800 (pto speed) and mowed 20 acres of hay non stop which took about 5 hours, it doesn't use oil and as never wet stacked on me, but I never let one idle around much, even if I'm puttering around on it I'll have the throttle set at 12-1600 rpm.
 
That is one great advantage of having a PTO dyno. You can break them in under load.One
cardinal rule is never idle a newly rebuilt diesel engine or rebuild it,run it a little
and and park it for six months. Ask me how I know. The rings will never seat. I had a
friend in the coal hauling business some years back. Never ran anything but Macks. He
did all his own mechanic work. He had a test stand that he broke his new rebuilds in on.
I was at his shop one day as he was putting on one the stand. He hooked everything up,
started the engine, let it idle for about 90 seconds, checked the oil pressure and made
sure it didn't have any leaks, ran it up to 1000 RPM and said let's go get a cup of
coffee. We came back in about 15 minutes, he looked everything over,grinned real big,
pulled the throttle wide open and said if she runs like that for 8 hours and don't blow
we'll put her back in the truck tomorrow and she be hauling coal the day after.He did
every one he rebuilt like that and he did a lot of them.
 
Curious why it would wet stack on a road run, thermostat not letting it up to temp or something? I often run mine on the road places and feel it's good for them gets em hot and working hard pulling the hills
 

On the few tractor drives I've been on they set the speed for the slowest tractors, in high gear that was just a little above idle on mine.
Cruising on the road at low rpm doesn't load the engine, nearly the same as setting and idling.
 
Engine still does not work very hard in high gear at 11-14 MPH on most drives. Did have one drive in Minnesota that had three speed groups, 10-12, 12-15, and 15-18. Neighbor friend and I ran the fast group, and starting out both the bike speedometer and GPS showed we were running 21-22 MPH. That's a bit fast when I want to see the surrounding scenery, had the leader slow back to 18 after the first break stop.
 
(quoted from post at 19:48:24 11/18/17)

Being it's a TLB it's hard to take it out and work it hard under a constant load like pulling plow or disc, but the main thing is to get some heat in the engine. If you have some work to do with it after it's warmed up a little rev the engine to 1800 rpm and leave it there while you using it. If you don't have much to do with it at the moment just rev it to 1800 rpm and let it set and run like that for 2-3 hours non stop.
We don't plow anymore so when I rebuilt my 4000 I let it run for a few hours at 1800, then when hay season started I hooked it to my mower, set it at 1800 (pto speed) and mowed 20 acres of hay non stop which took about 5 hours, it doesn't use oil and as never wet stacked on me, but I never let one idle around much, even if I'm puttering around on it I'll have the throttle set at 12-1600 rpm.


I would like to thank everyone for your feedback. It is true; so far I have not worked the engine as I have been working on the hydraulics so I can raise and lower the buckets in order to move her around.
It has only idled between 1,000 and 2,000 rpms and I have noticed it runs very cool at about 140 degrees according to the temp gauge I added which may not be accurate. The temp gage on the Instrument panel gets about midway, but again I don’t know how accurate that is.
It is using the standard 168 degree thermostat which sounds low to me, but I am use to gas engines which use 180 thermostats; this is my first diesel so I am still learning.
I should have her movable in another day or two and I will be able to apply a load to the engine. Hopefully that will raise the temperature and help with the stacking.
 

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