Allis chalmers 433t motor smoke
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=178490
Printed Date: 14 May 2025 at 6:26am
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Topic: Allis chalmers 433t motor smoke
Posted By: ac89
Subject: Allis chalmers 433t motor smoke
Date Posted: 20 Feb 2021 at 7:23pm
| Hey everyone. I have a 82 allis chalmers 715c backhoe with the 433t motor. Engine runs beautifully. The only thing is that it smokes blue smoke when it is idling. If I give it half throttle the smoke goes away completely. What would cause this? Injectors? To much fuel? Valves? I don't really want to tare Into it to much because it runs very well. It does start hard but that's how alot of allis chalmers are. Also want to add it doesn't use oil ive checked it since I bought it around a year ago and it doesn't use oil. |
Replies:
Posted By: HD6GTOM
Date Posted: 20 Feb 2021 at 9:41pm
| 2 things come to mind, check the timing and are you using truck stop #2 diesel fuel. If you are, buy yourself some premium #2 fuel. Most farm COOPs have it. A lot of independant owned fuel suppliers don't. |
Posted By: ac89
Date Posted: 21 Feb 2021 at 5:56am
| Ok I may try the fuel. I have tried a couple additives. |
Posted By: DougG
Date Posted: 21 Feb 2021 at 2:40pm
| Kinda sound pretty common - did it just start this ? |
Posted By: TramwayGuy
Date Posted: 21 Feb 2021 at 4:03pm
|
Does the crankcase oil smell like Diesel Fuel? The reason I’m asking is that you could have (2) problems! Engine oil getting past the rings; and fuel getting in the crankcase. So over time, the burned oil is replaced by Fuel. Not a good situation. The rate of fuel leaking would have to be the same as the oil burning. |
Posted By: DMiller
Date Posted: 21 Feb 2021 at 6:48pm
| My 180 does this, called 'Cold Oil Slobber' on older Low Compression Diesels. Do not maintain adequate Low Speed compression pressure or oil ring contact scrub to reduce engine oil on cylinder walls, thus 'Blue Smoke' exhaust. Fuel not being burned is White Smoke, Excess Fuel burning is Black Smoke, Oil Consumption (Regardless rate) is Blue Smoke and Steam is consuming coolant. |
Posted By: ac89
Date Posted: 22 Feb 2021 at 12:05am
| No it's smoked like this since I bought it a year ago. Ive checked the oil and its fine it doesn't have diesel fuel smell to it. It's a good running motor it does start hard. But with a small shot of ether it takes rate off no problem. Could be maybe the valves are out of adjustment? The valve cover gasket needs to be replaced so maybe I should check out the valve tolerances. |
Posted By: DougG
Date Posted: 22 Feb 2021 at 8:07pm
| No I wouldnt - those dont change much - but Id say its common and run it ! Id be interested if it comes up for sale |
Posted By: DrAllis
Date Posted: 22 Feb 2021 at 8:20pm
| 14 to 1 compression engines will do that especially if ambient air temps are cold. Quit idling it so much. |
Posted By: steve(ill)
Date Posted: 23 Feb 2021 at 8:40am
Fuel not being burned is White Smoke, Excess Fuel burning is Black Smoke, Oil Consumption (Regardless rate) is Blue Smoke and Steam is consuming coolant.  ------------- Like them all, but love the "B"s. |
Posted By: ac89
Date Posted: 23 Feb 2021 at 5:57pm
| Ok thanks everyone for the input. I'm going to leave it alone aside from replacing the valve cover gasket. As far as selling the machine goes that's a no go. I'm big into allis chalmers and finally found a decent ac backhoe. The transmission is very strong and brakes work excellent. Eventually I want to restore the machine to like new condition. |