Blue smoke after coasting (2lte)

[Postoy]

I took the might Prado on a 550km journey to see family and to do some skiing over new years and that involved me having to tackle some fairly large hills. I was quite nervous with the 2lte track record but I think the on average -10 weather and my light foot kept me out of the red and it took on the mountains like a champ (while maintaining 22mpg). I did however notice that after coasting the truck as soon as I let my foot on the throttle again it would sputter and puff blue for a couple seconds then clear up. I have noticed this as well on a couple wheeling trips but it wasn't as obvious as this. Anyone have a similar issue come up?

 

[NGray]

I'm sure you know this, but in case not, http://www.cruisingworld.com/how/read-those-smoke-signals

 

[Gun Runner 5]

"How to read smoke signals" ............
George Custer would have paid a fortune for that web site.

 

[GTSSportCoupe]

A lot of people don't realize it, but diesel smoke can be blue (depends on the particulate size). So don't immediately assume it's engine oil being burned. Mine blew blue at one point early after I got it, but no longer does since I've tuned it up and made the changes I have.

There is a filter in the valve cover (for the PCV) that should be cleaned. If it clogs you could be building crank case pressure which could make for a bit of oil getting into the combustion chamber. Any restriction in the PCV hose or clogged catch can will do the same. Did you go through any oil?

I've vented my PCV to atmosphere, and after a hard run it stinks a bit.

 

[NGray]

Good to know about the blue smoke. Thanks for posting that.

 

[GTSSportCoupe]

Good to know about the blue smoke. Thanks for posting that.

No prob. I learned that from a denso injection pump manual (ECD-V3). I've attached a pdf of the section on exhaust smoke (to this post). It's worth a quick read.

 

[BCR4619]

To the OP, which diesel are you using. Chevron does this to me if I idle or coast, no spider thou... Clears up when running up hills or constant load

 

[Postoy]

Mostly Shell, I worry that it is an injection problem. I also have been noticing that it takes a lot longer to start in the morning and misses and spews smoke for about 3 min.

 

[GTSSportCoupe]

Mostly Shell, I worry that it is an injection problem. I also have been noticing that it takes a lot longer to start in the morning and misses and spews smoke for about 3 min.

Have you checked your glow plugs (resistance)? If you need new plugs, I HIGHLY recommend the bosch duraterm (available from ebay uk). I put them in recently, and they are excellent. Also, check the voltage at each glow plug electrode and make sure there is 11V there initially when the glow is started (will take two people to do this check). If there isn't 11V, you may have a poor connection somewhere.

Do you still have the factory glow system? If so, how many times do you cycle the factory glow time? I find when temps are -5C to 5C I need to cycle the factory glow three times to get a perfect smokeless start (probably 15-20 sec total glow time). 5C to 10C I need two cycles. Above 10C one cycle is enough. Been meaning for a long time to go with a manual glow system, just never got around to it.

Two other things I did that helped a lot with starting are: 1. removing the throttle plate(s) which gives way better compression at lesser throttle positions, as the engine can get all the air it wants. More compression means more heat. 2. I advanced the timing a bit. This helped a HUGE amount with cold starts, and even warm starts. I get a little more diesel rattle at idle when cold, not sure yet if that is good or bad, hahaha.

 

[GTSSportCoupe]

Forgot to mention, but advancing my timing a bit also got rid of the last of the blue diesel smoke issue I had. More thorough burn I guess. Seems to make the engine run cooler (more efficient?) also, as it takes longer to warm up now.