N Board Forum - Expanded Thread Page

Subject: Engine smokes during warmup

[Back] [Return to Top of Forum]

2NTony    Posted 09-10-2018 at 15:00:05 [URL] [DELETE]        [Reply] [Email]  
  • Engine smokes during warmup
  • Hi Guys, I've had my 2N for about 6 years now and have learned quite a bit about from this site and the other one. Most things now I can diagnose and fix myself, but I am still learning. I've got a problem that I don't know what to do with. The engine blows a lot of blue smoke during warm up. None at all, when she gets hot. The check chain behind the exhaust is wet and oily. There is a minor amount oil use now, where before there was none. I did not have this problem when I used the tractor to mow my 4 acre yard, but I went to a ztr last fall and the tractor has been sitting for a week or two and sometimes a month before I use it. A month ago I tried a ATF cylinder soak with no change in warm up blue smoke. Today, I had to move some stuff and again it smoked badly until it warmed up good and then no smoke at all. Purrs like a 74 year old kitten. Today, I added a full can of Sea Foam to the gas tank and plan to work it hard tomorrow with the bush hog. Sorry for the long post, but I want your advice. Rings, valves, something else, etc. Many thanks in advance. Tony

    Chy NY    Posted 09-11-2018 at 11:02:08 [URL] [DELETE]        [Reply] [Email]  
  • Re: Engine smokes during warmup
  • Hi Tony, My 8N mower tractor leaks a little from the side cover on to the muffler. Upon starting, smoke seems to come from the exhaust, after it is burned off, no more smoke. This might be your situation. Chy NY

    2NTony    Posted 09-11-2018 at 09:03:02 [URL] [DELETE]        [Reply] [Email]  
  • Re: Engine smokes during warmup
  • To answer the questions about why not a full rebuild when I had the bearings replaced and the oil pump rebuilt. In hindsight it would have made sense. It was never mentioned to me because 1.)the compression test numbers were excellent, dry 115 to 128. 2.) it went in for loss of oil pressure and a pump rebuild. 3.) They kept it from April to July and it came back to me two different times with no oil pressure after warm up. Come to find out they thought the bearings looked OK and never miched them. At my insistence, they finally found I needed bearings and a crank grind too. All told, I had more in the lower-end rebuild than I did in the tractor. In the end, I was as tired of borrowing my brother in laws mower. as he was in loaning it to me.
    I told them to just button it up, and give it back. In retrospect, I should have redone the rings, pistons, and valves. In retrospect, I should have just knocked it in the head and bought a better tractor. All I can say to you who second guess me is hindsight is 20/20. In the heat of the moment, "excrement occurs".
    Live and learn, Tony

    John in MIch    Posted 09-11-2018 at 19:32:39 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Engine smokes during warmup
  • No way for us to know the service problems that you had. We answered based on the information provided. All (or at least many, including me) have had to learn the hard way and have also experienced poor service. We try to do better "the next time".

    K.LaRue-VA    Posted 09-11-2018 at 07:11:02 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Engine smokes during warmup
  • I've seen a few that didn't smoke once they got warmed up. Usually they still smoked, just not as much. When I hit them with a sudden load, they always burped out more of that blue smoke. Worn or broken rings is the most likely reason. Either pretend like it's a diesel, and keep running it, or do a ring job.

    Tim Daley(MI)    Posted 09-11-2018 at 05:23:49 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Engine smokes during warmup
  • Blue smoke = oil. Black smoke = too rich a fuel mixture. White smoke = moisture, either condensation in the oil or leaking coolant. Do you have a thermostat installed in the upper radiator hose? IMHO adding any of the 'snake-oil' products sold today are really not doing anything but thinning out the oil and or gas depending on where you are adding it. It may loosen some crud, and will not hurt anything internally and you can get the same thing from mineral spirits, which is the main ingredient in all those products anyway. You could just dump some paint thinner or charcoal lighter fluid in as they are 100% the same thing, and cheaper than the commercially sold products, about $10 per gallon. I agree with John. It's a lot of work to tear down an engine and so why not do the job right the first time?

    Tim Daley(MI)

    2NTony    Posted 09-10-2018 at 17:28:13 [URL] [DELETE]        [Reply] [Email]  
  • Re: Engine smokes during warmup
  • Just a thought, I had my bearings replaced, crank ground and oil pump rebuilt the summer before last. This spring I changed oil to 15-40 Rotella. IIRC I was using 20-50 Rotella prior to the rebuild. Is my oil too thin at startup? I am using AC 437 plugs.

    John in MIch    Posted 09-10-2018 at 19:36:19 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Engine smokes during warmup
  • Having been that far into the engine, rings and sleeves would have been an easy replace at that time.

    TheOldHokie    Posted 09-10-2018 at 18:21:29 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Engine smokes during warmup
  • Is my oil too thin at startup?



    John in Mich    Posted 09-10-2018 at 15:30:46 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Engine smokes during warmup
  • My first reaction would be that the rings are worn and asking to be replaced
    BUT, first I will ask what grade of oil are you using? For summer I only use a straight 30wt for my climate. Others may use a 40wt or 20w50. These will not fix worn rings but will slow down burning oil.
    You said you did a tranny fluid soak. Did you then change the oil?
    Also, you might want to pull the spark plugs and clean or replace them. Use hotter plugs than Champion H-10. Use H-12 or, I prefer, AL437. As I understand it, the hotter plug also helps burn the ethenol fuel.
    That is my story and I'm sticking to it.

    [Back] [Return to Top of Forum]