MF 2660 Perkins Smoke

[Dmacleo]

Yeah a pressure test takes moments to do and is a real useful diagnostic test.

 

[thepumpguysc]

I think what they’re telling you is, go see if u can borrow a test kit.. I know Advance Auto Parts loans tools .. call around and find out who rents/loans radiator pressure test kits..
They come with different adapters & don’t tell them it’s for a tractor, if u can help it..
Good luck

 

[JWR]

One more theory: a local mechanic tells me that some diesels have a small cooler on the EGR gas headed back for the intake of the engine. I have not done the service manual study yet to see if this Perkins has an EGR cooling system or not. Anyone know ?

If there is an EGR cooling system (using radiator coolant circulated through a tiny heat exchanger) it raises the possibility that anti-freeze/water might leak into the heat exchanger in such a way as to accumulate some liquid which might then move with gravity forward or backward in the cavity when operating the tractor uphill or downhill. Seems possible that the leaked coolant gets into the intake more when tilted (one way or the other.) I'm not saying that is what happened but it is the only theory I have heard so far that might account for it smoking only going downhill. Also fits that the first time it happened was a lengthy smoke period (minute or more) and from then on the smoking was more limited and smaller amounts. That would fit with the leaking coolant having pooled, gotten mostly burned off during the first extended downhill driving and then was smaller later in the absence of time to pool.

This theory came from a mechanic who had this (the leaking, not the uphill downhill aspects) happen on a Cummins diesel school bus. On it he has a tiny heat exchanger with a coolant flow leak. We do not yet know if my Perkins on the MF 2660 has such a thing or not.

How on earth to diagnose this (even if it happened to be true) is beyond me. Potentially there is shop test equipment (for tractors like those intended for EGR testing in automobiles) that would show a particular code for a valve failure (stuck open or stuck closed) but probably not for coolant leaks.

Meanwhile I got a radiator pressure test kit to use next time I get to the tractor.

 

[DLTrekkers]

What airfilter was installed on that tractor ?
A drie airfilter or a oilbath ?
If you overfill an oilbath just a little bit it will suck it into the engine.

 

[JWR]

What airfilter was installed on that tractor ?
A drie airfilter or a oilbath ?
If you overfill an oilbath just a little bit it will suck it into the engine.

Dry. I had just cleaned it out via air pressure recently.

 

[JWR]

Time for an update: I was able to get to the tractor New Years Day 1/1/23 for a few hours and found the following:
1) Had purchased a cooling system pressure test kit [$58, Amazon] and one of the supplied caps with pump and meter hose connection fits the MF2660 radiator. Ran 45 minute pressure test at 15 psi and there was no drop off in pressure. Stayed the same.
2) Coolant level in the radiator was well above the coils and just as clean and greenish-clear as can be. Surprise since it has been in there for 12 years untouched. It did take about a quart of 50-50 mix to top it off. Obviously going to flush and replace coolant this spring.
3) Ran the engine for probably 30 minutes or so total that day. No sign of smoke (but then it never did smoke last month until I was going downhill...) I did not have it out running in the fields. Will next trip.
4) Took many pictures. Cannot find anything looking like a "thermostart" (someone had mentioned in post #4 ) with wires running to it and relation to the intake.
5) Cannot find the EGR. Spent an hour trying to chase those details in the shop manual and Oper Manual before the trip and could find no ref to an EGR valve or plumbing. Blasted manuals without a good comprehensive index justify shooting the publishers don't they?
6) Oper Manual DOES SAY [in troubleshooting section] that the crankcase ventilation "breather" tube can be clogged and need cleaning and can cause bluish smoke. Stands out like a sore thumb -- why puzzle until I have used that info?? Was not prepared nor had time to dig into that this trip. Must do so of course. Pulling the breathing tube looks like it may take some contortions and time...
7) Next: operate the tractor more to include up/down hill and see if smoke still occurs. Remove and clean the breather tube per manual. Retest in the field. I'll let ya all know when this is done.

 

[JWR]

7 months later another update:

• In June using the MF2660 for 3hrs each of 2 days in a row there was blue smoke every time going downhill and once or twice just sitting on the level.
• Lowering rpm from 1800 to around 1500 seemed to reduce the smoke if not stop it
• Oil and coolant levels show no change; proper levels
• Two experienced mechanics have suggested recently that the source is VALVE SEALS.
  • One saying that evidently one or more front seals are bad/sloppy and that is why "downhill produces smoke"
  • The other saying that when the engine is not used often the seals get dry/brittle and tend to let some oil by into the cylinders. I typically use it once a month for a couple of days.
• Oddly this week I used it for very steep ground bush hogging and misc "weeds" for about 3.5 hrs. with no sign of smoke at all except for one burst of a few seconds.
• After using it I ran low pressure compressed air into the rocker cover breather tube. When released there was a rush of air pressure release as expected. Have yet to remove the breather tube and clean it thoroughly as the owner's manual suggests but it seems unlikely to be at fault.
• So far have held back and not used Barr's Leak Stop or similar additives to soften up the valve seals.

 

[JWR]

8 months later Update:

Still a puzzle ...but it has not collapsed ... yet

• In August like earlier in the summer I used the MF2660 for 3hrs each of 2 days in a row. Now there is blue smoke SOMETIMES going downhill (quite often but not every time) and still rarely if sitting on the level.
• Oil and coolant levels show no change; proper levels (though the oil level has been very slightly overfilled for many months since last change sometime on 2022. Long before any blue smoke ever showed up.)
• These are still the "Prevailing opinions." Two experienced mechanics have suggested recently that the source is VALVE SEALS.
  • One saying that evidently one or more front seals are bad/sloppy and that is why "downhill produces smoke"
  • The other saying that when the engine is not used often the seals get dry/brittle and tend to let some oil by into the cylinders. I typically use it once a month for a couple of days.
• At end of August's utilization (~ 8/12/23) I used Bar's Leak Stop oil additive to soften up the valve seals. Not enough time / hours on it since that to see if that will change anything.
• Even now this thing has only approx. 580 hours on it since I bought it brand new in 2011. Garage kept, regular oil changes, etc.

Any fresh opinions ??

 

[ROUSTABOUT]

No, lube oil in a diesel, if burned, puts out some really black smoke, not blueish.



No distinct puffs. It ran the entire time like nothing ever happened. I did throttle down to idle AND up to higher than normal operating rpm during the smoking and could see no change. No missing, no stumble, no change in the smoking.

No. No change in power output.

Not sure about fumes but EGR systems on a VW diesel can put lube oil in the intake and the result is black smoke out the rear -- big time!

No apparent engine oil usage. Checked it after this incident and had checked it a month ago. Right at the full mark, no change.

Amen to that ! Tell me about it! I had a VW diesel start sucking engine oil from the crankcase due to excessive blowby in it's old age. It fogged the entire highway with sooty black smoke for 1/4 mile until I finally figured out what was happening. Key would not shut it down of course and I had to put it in high gear and use the brakes to stall the engine. Thank goodness it was a stick and not automatic! That happens you will never forget it. Using air intake blockage is about the ONLY solution if it had been an automatic. And that never occurred to me so I would have lost the engine if it had been automatic.

Ours put out a royal blue cloud. Looked like we were creating a thunderstorm. Every time we stopped to tie a bale and dump it. Cure is to put motor oil in your diesel fuel.

 

[JWR]

Ours put out a royal blue cloud. Looked like we were creating a thunderstorm. Every time we stopped to tie a bale and dump it. Cure is to put motor oil in your diesel fuel.

First, the phrase you quoted from me "...lube oil in a diesel, if burned, puts out some really black smoke, not blueish." was my mistake. That was based on experience using a diesel VW which had so much blowby that it began to ingest and burn it's own lubricating oil from the crankcase -- and that DOES put out the blackest of black clouds. However I now realize that clean lube oil in the combustion process in tiny amounts does produce bluish smoke. OK, that mistake of mine corrected ...
Are you serious -- put motor oil in the diesel fuel !? What does that do? And if that corrects some issue what was the problem in the first place (aside from the visual shock of bluish smoke) ?? Which of your tractors put out the 'royal blue cloud?'
Tks.