# Yanmar 186 Diesel White Smoke and Won't Start



## Jason Bourgeois (Aug 18, 2020)

Hi Everyone,

This is my first post on this forum.

I bought a Yanmar 186 about 6 months ago. It has never given me any issues, and the fluids have stayed full. I only used it for pulling a box blade around my yard and pulling an empty trailer around.

A couple of weeks ago, I accidentally left the ignition switch turned on and drained the battery. I was able to jump start it and let it run for a while. It ran fine. I charged the battery and let it sit for a couple of days. When I restarted it, I drove it across the yard to hook up the box blade. After 1 minute of running, it started knocking (which it never did before) and started blowing white smoke. The RPMs lowered, and it shut down. When I tried to start it, it continued to blow white smoke and didn't start easily. After a few minutes, it started and ran for a minute, then started blowing white smoke and died. Now it won't even start. When cranking, it blows white smoke. 

Here's a video. https://photos.app.goo.gl/NnQn4yv2vub1WdMBA

I have read some information about white smoke in diesels and assume it is either a problem with the injectors or the compression.

Does anyone have any ideas? I may bring it to a mechanic, but I'll try to fix it myself.

Thanks,

Jason


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## HarveyW (Sep 15, 2014)

Hello Jason, welcome to the tractor forum.

To me, white smoke is unburned fuel. This is based upon observations with my own tractor when it won't start on a cold day.

Has your tractor always cranked over this easily, or has it lost compression???

I think you need to do a compression test on your engine, which requires special equipment for a diesel due to the higher pressure.

You can check for flow from the breather on top of the valve cover. Put your finger over it to see if it actually builds up pressure while cranking/running.


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## Jason Bourgeois (Aug 18, 2020)

Harvey,

Thank you for the advice. 

The tractor has always started within a second of cranking, so I don't know if there is any difference from before in the cranking.

I'll check the breather today.

Thanks,

Jason


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## Randyphoenix (Jun 23, 2020)

Jason Bourgeois said:


> Hi Everyone,
> 
> This is my first post on this forum.
> 
> ...


Check your Diesel fuel water separator. On the separator there should a petcock or plug for you to open to drain the water separator.


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## TX MX5200 (May 12, 2020)

Agree on the water fuel drain...and check out the fuel filter.

I will add I had same issue with my yanmar tractor...I put 2 new batteries in and still slow cranked and blew white smoke....once started it would run long enough to get to pasture and power down and stall.

I was thinking bttry didnt have enough crank amps so called a shop 5 hours away and reached a helpful old timer....told him my delima and he immediately said to remove both ends of bttry caplets and clean connections......for me it was a hoooorah, cranked right up and ran like a champ. Hope it's that some for ya.


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## Jason Bourgeois (Aug 18, 2020)

Thanks for the advice!

A guy in my neighborhood came over this morning to help. We cracked the injector lines and saw a bunch of water in the fuel. We changed the fuel filter, which also has signs of water damage, and drained most of the fuel out of the tank. We put new fuel and bled the lines incrementally from the filter to the injectors. A lot of water came out. It cranked right up and ran great after that.

I had washed the tractor before it stopped running. I obviously got water in the fuel tank, which got to the cylinders. That's why I was able to run it for a minute or so before it died. I'm going to check the tank to see how water was able to get in. It's never been a problem after rain.


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