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Pete, Technician
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Experience:  17 years automotive training and experience.
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Mitsubishi Delica L400 Space Gear: Hello Mitsubishi Mechanic,

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Hello Mitsubishi Mechanic, I hope you are having a great day! I am having issues whereby my 1995 L400 (2.8 liter turbo diesel). A few weeks ago it started belching substantial amounts of black soot out especially once I have stopped at a light and then accelerate away. It is also running rough. On initial start up each AM after the glo plugs heat up, it starts right away but once fully warmed up and after some driving, it becomes more difficult to start again; it takes several seconds of cranking. Also when i sit at a light etc. for a few seconds at idel then take off, it hesitates then puffs out the black smoke. Is there some valve, dashpot, regulator or other component which might have gone ary? Or, could it be my fuel source here in British Columbia has changed? I should add that the van for several months has been using about a liter of water every 200km or so. I can't find any leaks and have not seen any froth in the oil filler hole of the valve cover. And nor have I seen any droplets in the oil or changes in oil level. I replaced the water reservoir tank cap in case that was weak. Any insight will be greatly appreciated!!!! Cheers, Jeff
My name is XXXXX XXXXX I am a professional here at Just Answer/Pearl. I noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

With black smoke like this and rough running this sounds to be a possible fault with one or more fuel injectors.I have seen diesel injectors fail several times in the past and cause the rough running as well as the smoke here and sounds like what is occurring here.

The injectors should be tested to see if this is the case.If one or more are found at fault then the affected or all injectors should be replaced.

As for the water loss if you have no external leaks and no water in the engine oil at all I suspect you may have a leaking head gasket.It may be small constant leak that is being burned off in the cylinders and this can make it difficult to locate but usually this is the case when there are no other leaks located or water in the engine oil.

Thanks Pete
Customer: replied 3 years ago.

Hello Pete, Thanks for the reply. If a head gasket is suspected re. the steady water loss, why are there no water droplets or froth in the oil filler hole of the valve cover? And more importantly, if this level of head gasket leak is occurring will the anti-freeze leaking into the cylinder glaze the cylinder wall and or piston rings?

From a different angle, is the rough running and belching smoke possibly related to a plugged fuel filter?


Thanks so much! Jeff

Usually a plugged/restricted fuel filter wont cause excess smoke like this here and usually this would cause a hard starting or no start issue if the filter was the case and lots of power loss.I suspect this is still an injector fault.

If your coolant is leaking into the cylinders and is being burned off in the cylinders usually you wont notice an issue with milky oil or froth in the oil filler hole in some cases.I have seen several head gasket failure issues before where the coolant was being burned off in the cylinders and no sludge or frothing had occurred.I assume that after an extended time like this though you might see some signs of water in the oil but with what you have described with no leaks and no water in the oil but using coolant I suspect the coolant/water is being burned off in the engine cylinders.

As long as it isn't a large amount entering the cylinders the engine would usually burn it off and wouldn't cause any damage to the engine but if it is a large amount to where it is causing rough running or excess smoke I have seen the water/coolant work its way into the oil past the rings and damage the crank bearings.

Thanks Pete
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Customer: replied 3 years ago.

Hello Pete,


Thanks for the great details. I have suspected the head gasket but did expect seeing froth and droplets in the oil filler. Your detailed answer helps confirm what Ibelived was the bad news. Again thanks alot and best to you!





Your welcome Jeff.Let me know if you need anything else and feel free to rate my help above when your ready.

Thanks Pete

I am following up with you to see if you still needed help with your question you had asked.If my help didn't satisfy your question please let me know so we can continue.

Thanks Pete

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