175 engine problems

Hello to everyone. I am long time reader here but rarely post, but I could use some help on t his one. My perkins 236 is "slobbering" from the exhaust. My mechanic freind and I have done everything to this engine, including head,pistons sleeves rings, injectors(twice), injection pump, all to no avail. All this and no improvement. Does anyone have an opinion on this? Thanks for any and all advice. Dennis

Is it all the time or just when you first start it? If it only happens when you first start it and it has the manifold starting aid it is probably leaking by when setting. I suppose it could leak enough to do it all the time. I had the problem on my 205 Industrial and Big Dean put me onto it years ago.

Diesels run much cooler at idle or light loads, and can have "exhaust slobber". Raising water temp can help. What temp thermostat is in it, if 160, a 180 will help. If engine runs and pulls well on a dyno, run it. It may need more run time to fully seat the rings. Also critical is how much below the head surface all valve faces are, this will lower the compression, make cold starting worse, and exhaust will drip cold too if valves are sunk in head too far. The closer to flush the better, but specs are in shop manuals.

Thanks for your replys. I really appreciate your help. Tractor has a 180 thermostat and I covered the radiator to bring it up to operating temp for two hours. "slobbers" worse at operating temp and higher RPM. Is it possible that the head has a crack in the oil journal that feeds the rocker arm. Tractor starts on the first turn and seems to run very nice. Puts 63 hp on the Dyno and does not smoke except on acceleration with a puff of lt gray. I am stumped!!!

Work it real hard, it may be glazing the bores, or as Phil suggests it may be the starting aid. Or even a poor engine kit?
Sam

Hi Just a few thoughts on this.
I"m working on a 3.152 Perkins motor right now. The pistons that are in it have multi piece oil control rings with 5 parts . when I was looking at ordering the parts there was an online tech sheet that said these ring parts had to be installed a certain way. I wonder if you had these type rings and they are put together wrong.
glazing is possible but I never had a motor this bad from start up and a few hours from rebuild.

I wonder could there be a miss match on rings to chrome cylinder sleeves i know some perks had chrome and some cast and seem to remember the rings have to match right for the sleeve type but not sure if your motor could have both types fitted.
The other thing that might sound stupid, is the muffler full of oil from before the repair and as it heats and revs it pushes it out more.
I had a Belarus in the shop once for a guy. I did the head on it. It had been lightly used and started with either due to bad valve seats.
when I got it running it slobbered stuff from the exhaust after an hour warming. I thought here we go more problems and the rings are bad as the guy never wanted the pistons pulled or anything else checked.
I started thinking and took the muffler off. it was full of sticky goo that was also in the head on removal. so I took a tiger torch, set it in the inlet of the muffler and burnt all the goo out. it whistled like a jet motor for about 10 mins. I put the muffler back on and it never slobbered again.
Hope something here will be useful or someone else will know about the rings and sleeves.
Regards Robert

Is it using oil? If not, sometimes the slobbering you talk about can be a result of the type of muffler you have on it or the ambient temperature. Some of the large quiet type mufflers can run very cool, and then condensaton will leak out the bottom. The condensation and soot from the diesel exaust turns black and drips out. Running in cold weather or light load for long periods can cause the same thing.

Thanks again for the great advice. Maybe a little background would be useful. I bought this from a neighbor with 1900 original hours. It was wet stacking when I got it and the head had been off as there was not paint on it. Thought by working it hard for awhile it might clear up, no such luck! Changed the injectors with no change, pulled head and had that rebuilt, new valves, guides, and seals, no change, pulled it down and installed new sleeves pistons rings and seals, no change, still wet stacking. Removed intake and exhaust manifolds and started engine, intake side was dry and spotless, exhaust side wet with slobber. Pulled injector pump and injectors and had rebuilt and tested, set to specs, no change! My point is all this work and there is no differnce from when I started. My thought is there has to be a cracked head, The machine shop magnifluxed(sp?) the head and said it was good. Sorry for the long post. Dennis

Hi
Sounds like it should be a good tractor if you can get it right. I would not want to make the call on changing for a new head. If it still does it then that was an expensive trial and error, If nothing the other guys have said works.
I don't know how the guys do the magnaflux on a head. I always take them to the motor shop and bring them home done/ready to go if it checks out ok.
I have heard of guys taking parts to the local friendly family doctor/hospital, or vet and having xrays done to find cracks before, wonder what would show on that head for a small financial gain in there pocket!.
Regards Robert

Doubt you have any trouble at all, this shows up more often too below 50 degrees. Dad's 180 does it too. Tractor has no chrome sleeves like was used on some 203 perkins, did not come with a thermostart in US like 65, 85, and S90 came with. At least I never saw any on tractors sold by th MF dealer I worked for. Injection pump has no advance to be set wrong. Diesels need heat to burn clean.

Is it oil in the exhaust or is it fuel? Must determine this first.

When ours was dripping oil out of the exhaust I took the exhaust manifold off and could clearly see the oil running down the exhaust valve stems.

I would remove the exhaust manifold and clean everything up and run it to see if you can get a clearer idea of exactly where the oil (or whatever) is coming from.

JP.

P.S.: Have you checked compressions since the rebuild? JP.

Thanks to all that responded to my questions. Great advice on this forum. To answer some of your questions, The machine shop that did the head and rods/pistons is top notch. Owner is very particular. Machined out valve stem holes and installed bronze valve guides, and insalled all new valves to meet the valve protrusion spec. Engine kit came from TISCO and had no chrome sleeves. Muffler is new but does not matter if on or not, still wet stacks. Diesel shop that did injectors and pump also tops in this area. I still believe this is a head problem. Did Perkins change the head design in 1974? I ask because my head is not the same as in the parts book or the one on my 180. Again thanks to everyone who has given this some thought and responded. Dennis

we had a MF-90 that was slobbering and it did that for years till one day the muffler rusted of and i put a straight pipe on it turned out the muffler was to big and would not get hot and moisture would forum in side and made a mess. sure sound like you have a heat problem by running to cool

Bought a MF 255 with the 236 perkins.It had been dusted out then rebuilt.It then also pushed oil out of the exhaust badly.I tore the engine back down and found the 2nd and the 3rd scraper rings upside down.Its the rings between the compression and oil ring.The scraper rings do just as they are named,scrape down the cylinder cleaning off any oil left by the oil rings.Turn this ring upside down and it will push oil into the combustion cylinder.Also payclose attention to the intake gaskets and bolts.Some of the bolts go thru into the crankcase and can pull oil out if the gaskets are out of place.Fixed mine and no oil usage.

bought a 255 with a 236 recent rebuild, when delivered had a note attached no warranty as is, slobbered 2 qts.and better a day running at 1200 rpms pulling a potatoes digger no real load, after potato harvest removed head it had new pistons and liners, #2 cylinder had a 3" vertical crack ,valve guides were worn out it ran perfect other than slobbering oil,rebuild it myself all new parts still going strong after over 20 years,perkins used chrome liners and rings also cast rings and liners any combination would work except chrome on chrome they will never seat, seen parts packaged wrong several times at my time and expense