New to the site and looking for some advice. I bought a 40xt with 1900 hours. Runs good. Had to replace drive motors but was aware of that comon problem. She runs good/ good power / starts as she should. This winter and spring I have noticed a smell of burning oil. Does not happen all the time sometimes under a load or change in rpm I will notice it. Can't see any smoke I the exhaust. It has gotten more noticeable lately so today I pulled the cab forward while running and played with the throttle a bit. When I bump up the throttle enough I could see a little puff of white smoke from the exhaust. It smells like burning oil but is white. Could have some blue tint to it but looks white. Had to do it a few times to make sure I was seeing smoke. She does not use oil or water and she runs fine but the smell scares me!!! If I had not flipped the cab and watched I would have never seen the smoke. She does not smell when idling or running even at full Rpm. I asked around and got everything from moisture in the fuel to bad injectors and loose valve guides and broken worn rings. Anyone have any ideas?
If it smells like burning oil it's probably burning oil. Oil does smell differently when it's burned off the exhaust than it does if it being burned inside the engine. Does it have any leaks, mainly around the valve cover that may be getting on the exhaust? If it is burning oil you would probably see the smoke under a load as well as when you rev the engine.
I looked hard and don't see any leaks. So valve guides sloppy rings? I would eat off the thing it's that clean Little dust. That's it. Is there a way to check for bad rings valve guides? I would have thought if she's blowing by the rings or valve guides it would burn oil all the time.
Kinda hard to tell what it smells like from here, but what the heck. How about shooting the temps on the exhaust manifold to find if one cylinder/injector is suspect? If you're really not using any oil then maybe unburned diesel from a bad injector/valve, or timing off somehow? Usually you have to be burning a fair bit of oil to smell it in the exhaust. Like Todd said though, a little on the manifold WILL smell. How many hours have you put on it? Have you drained any water from the tank or filter/water separator? Bad rings or valve guides would use enough oil to notice it on the dipstick before you'd smell it in my opinion. With no turbocharger I can't see how they would cause more oil use at different conditions (like a gas engine would suck oil at high vacuum). Also that would be awfully bad engine life for that engine at a lower HP rating. If the manifold temps check out similar, I'd be sure the oil isn't gunked up, maybe run some biodiesel if you're into that sort of thing, and use it hard enough to get a workout.
I've been around motors my whole life. Diesels are new to me tho. It smells like oil burning off the maifold after you spill a little bit when you change oil in the old farm truck. That smell is quick after rpm change or load change on the motor drawing down the rpms and after today seeing the little puff when increasing RPMS while watching it. Is that a sign of bad rings or valve guides. (the begining of wearing out?) That smell goes away as quick as it comes on. For a couple weeks now I would get out when I smelled it. By the time i made it to the rear of the machine the smell would be gone. I thought I was losing my mind becasue I thought I would find a leak somewhere but I cant find it or see it. Today was the first day I saw the smoke and could smell at the same time. No matter what motor I've played with that smell to me has been the smell of all out danger. I was hoping someone has had the same issue and can point me in the right direction. I'm gonna look for a leak again around the valve covers but I'm leaning towards internal issue. I'm wondering if she does need a good day of work of that good day will blow her up.....Thanks in advance !!! I have not started anything yet in the process of figuring it out. I live in Minnesota and do not have a heated building where she sleeps. plug her in the night before I need it and she runs like a champ in -30 temps. not because I want to but the cows need a bale. I know condensation in the fuel tank could be an issue. I will try to drain the bottom off by removing the plug in the bottom of the tank. I opened the fuel filter water seperator but only got fuel. It was cold that day maybe it was frozen in the filter. I have put 130 hours on the machine since I bought it. I dont run it much only feed hay and plow snow when we got some. I'll see if I can find someone with a thermal temp gun. I changed all fluids/and filters last spring and was waiting till more warmth to change oil/filter this spring.
If there was much ice in the separator it wouldn't drain fuel out. Condensation is NOT a problem during winter, no moisture in the air. Plugging it in helps to start off with a warm engine (an hour is plenty though) but it sounds like it's not being used a lot at a time. That might be part of the problem? You should be able to find a used temp gun on fleabay for around $20 shipped, worth every penny in my book. I still think you'd notice the oil going down in 130 hours (same oil?) if something was going internally. According to the internet, that has a Case 4-390/Cummins 4B, no turbo, if anybody has smelled one like this before.
Do not overfill the crankcase oil, if overfull at all it may be getting some of that. If the oil level is in the safe zone that is good enough. Generally valve seals or guides being worn will cause oil smoke at startup and then clear up.