[tcurrie]

I have mensioned this in a previous post but I thought id start a thread specificaly for this.

My 81 will start to puff quite a bit of blue smoke only after extended periods of low idle like when I am out hunting and crawling slowly along logging roads. This is the only time it ever blows blue. If I rev the engine up, it goes away quickly. It dose not seem to use oil. After 6000kms it still has 3/4 on the dip stick

Any Ideas as to what might be causing this?

[Splittilps]

Don't have an answer but mine is the same. i don't think is anything to worry about. It got allot better after i started to use Howes in every tank.

cheers

[roscoFJ73]

Probably a bit of oil leaking down the valve guide seals.

[canadian bum]

Diesels natrually don't like to idle for long periods of time. Thats why if your going to let it idle there is a high idle on big truck engines anyways as well as a pull throttle on cruisers. Anyways a little oil just gets into the cylinder from idling for so long and causes the blue smoke. It maybe caused more so by having cooler combustion temps since the engine is not working hard and the RPM's are low further contributing to lower temps.

[tcurrie]

Well it sound normal then so I wont worry about it too much. Thanks all for the input.

[canucksafari]

Originally Posted by tcurrie

Well it sound normal then so I wont worry about it too much. Thanks all for the input.

Its normal for engines with worn valve guide seals but it isn't normal. It won't hurt anything as long as you keep an eye on your oil level. IMO, the best thing is always to replace worn parts. The valve guide seals usually are not expensive. It's just expensive if you have to pay someone to replace them.

[Greg_B]

Canadian Bum has a good explanation.

In addition, there is a term called "loading up". Older diesels where the fuel delivery is not computer controlled are more prone to loading up at idle, but they can all do it. The 1st good throttle application will give that puff of white/blue and clean it out.

Don't excessive idle the engine. Look up the term "diesel glazing cylinder walls" in Google.

Elevation will make this more noticeable too.

[tcurrie]

Originally Posted by canucksafari

Its normal for engines with worn valve guide seals but it isn't normal. It won't hurt anything as long as you keep an eye on your oil level. IMO, the best thing is always to replace worn parts. The valve guide seals usually are not expensive. It's just expensive if you have to pay someone to replace them.

Any idea for an approx. cost to have then done?

[tcurrie]

Originally Posted by Greg_B

Canadian Bum has a good explanation.

In addition, there is a term called "loading up". Older diesels where the fuel delivery is not computer controlled are more prone to loading up at idle, but they can all do it. The 1st good throttle application will give that puff of white/blue and clean it out.

Don't excessive idle the engine. Look up the term "diesel glazing cylinder walls" in Google.

Elevation will make this more noticeable too.

Thanks, thats intresting. I guess it would be better to put her in low range in a 1st or 2nd gear and keep the RPMs up a bit when crawling along...what do you think?

[tcurrie]

I was just thinking about it some more and realized something else.

I often will start my truck 20 to 30 mins before going to work and I have never seen it puff blue as long as it has been idleing in PARK and under no load. It puffs blue only when the engine is in gear, under load, and low RPMs for an extended period of time.

Dose that angle change anyones valve seal diagnosis at all?

[canucksafari]

Underloaded for me would mean driving on the flat or going up a hill. I would expect it to burn oil at higher RPM is it was the oil rings. How much oil you going through in 5000 kms?

Did you check the intake from the turbo?

Lastly, are you sure it is motor oil smoke?

[lostmarbles]

I'm interested in the comments about prolonged idling being bad.

Diesel cruisers have been the "vehicles of choice" for roadside-weedspraying here for years. (Not so much nowadays though because they have become pretty well "priced off the market".)

And "idling" represents 90% of the mileage/engine-hours of such vehicles.



PS. I've never worried about getting out of my vehicle (to check a river crossing or whatever) and leaving it idling. - Although I admit I often pull the hand-throttle slightly to increase the RPM.

[tcurrie]

Originally Posted by canucksafari

Underloaded for me would mean driving on the flat or going up a hill. I would expect it to burn oil at higher RPM is it was the oil rings. How much oil you going through in 5000 kms?

Did you check the intake from the turbo?

Lastly, are you sure it is motor oil smoke?

I still have about three quarters showing on the dipstick after 6000 kms.

I have not checked the intake from the turbo.

I assumed since it was blue that it was oil. could it be something else? I know that there are at least three valves that need to be adjusted....could that have something to do with it?

[canucksafari]

If it is burning oil, it isn't much in 6,000 kms - only down 250 ml. My wife's Tercel eats in a week.

To confirm it is motor oil burning get someone to drive behind yourrig who knows what the smell of burnt engine oil smells like. If it smells like unburnt diesel, then the cause of your smoke is elsewhere.

If it is burnt motor oil smoke, you might try some of the engine purge additives that Greg recommended in the last couple weeks. At 6,000 kms in an indirect injection engine you are due for an oil change anyways. Not sure what the interval is for a direction injection engine like yours.

[Greg_B]

Originally Posted by lostmarbles

I'm interested in the comments about prolonged idling being bad.

Diesel cruisers have been the "vehicles of choice" for roadside-weedspraying here for years. (Not so much nowadays though because they have become pretty well "priced off the market".)

And "idling" represents 90% of the mileage/engine-hours of such vehicles.



PS. I've never worried about getting out of my vehicle (to check a river crossing or whatever) and leaving it idling. - Although I admit I often pull the hand-throttle slightly to increase the RPM.

Statistical proof because I'm a papered mechanic with 1000 rebuilds under my sleeve and the laboratory in the back room. Nope, not me.

The HD mechanics at work have mentioned this, and have asked we put the trucks on high idle when parked at an incident. This is for electrical load concerns as well.

From conversations with diesel mechanics, as I pick their brains.

Filtered through reading and research.

I bump the idle too when wheeling and stopped for whatever reason (when I remember), and I would not turn it off simply to get out and check something. I understand "excessive" to mean hours and hours.

TheDieselStop.Com - www.thedieselstop.com

http://www.wjwatson.com/files/runningin.pdf (diesel generator info)

Get past the marketing, there is some good information...from your neck of the woods: Colour of engine smoke and when it occurs tells about internal condition

Marine diesel engines: maintenance ... - Google Book Search

Piston glazing and your "modern" diesel - Australian Land Rover Owners

Tonnes more out there if you want to read...








And...

Scary stuff here: Diesel Talk Forums - Glazing of cylinders read the de-glazing post. Yikes!

[Greg_B]

Originally Posted by tcurrie

Thanks, thats intresting. I guess it would be better to put her in low range in a 1st or 2nd gear and keep the RPMs up a bit when crawling along...what do you think?

Probably. How's that for definitive! :-)

[Greg_B]

There's been a lot of questions over the years about diesel smoke, and what the different colors mean. There have been some good data and input from different members.

Maybe the mods can look at diesel smoke FAQ.

Here is the main data from the NZ link, without the hyperlinks. I think it jives with what some of the more experienced and knowledgeable folks have mentioned. What do ya'll think.


SMOKE COLOUR

Basically there are 3 types of smoke emitted from a diesel engine: black, blue and white.

Black smoke:

Black smoke is the most common emitted from diesel engines and indicates incomplete combustion of the fuel. Black smoke causes can vary widely and include ..
· Incorrect fuel injection timing
· Dirty or worn fuel injectors
· Over fuelling
· Faulty turbocharger, or turbo lag
· Faulty or dirty exhaust gas recycling (EGR) system
· Incorrect valve clearance
· Incorrect fuel to air ratio
· Dirty or restricted air cleaner systems
· Over loading the engine
· Poor fuel quality
· Cool operating temperatures
· High altitude operation
· Excessive carbon build-up in combustion and exhaust spaces

Black smoke can occur across the entire operating range, but is usually worst under full power, or during the lag before the turbocharger boosts air supply to match the fuel usage such as in the early stages of acceleration and during gear changes. Moderate turbo lag smoke is acceptable; otherwise black smoke should be hardly visible in a correctly running engine.

Blue smoke:

Blue smoke is caused by engine lubricating oil burning. The oil can enter the combustion chamber from several sources including:

· Worn valve guides, or seals
· Cylinder &/or piston ring wear
· Cylinder glaze
· Piston ring sticking
· Incorrect grade of oil .. too thin and getting past rings, or valves guides
· Fuel dilution of the oil, making it too thin.

Blue smoke is often evident at cold start, which can reflect reduced oil control due to carbon fouling deposits around the piston rings and/or cylinder glaze. Blue smoke should not be evident at any stage.
An engine may burn oil without the evidence of blue smoke, because good compression burns oil quite cleanly, however, it is not acceptable for any new engine, or engine in good internal condition to burn large amounts of lubricating oil.

White smoke:

White smoke is caused by raw, un-burnt fuel passing into the exhaust stream. Common causes include:
· Incorrect fuel injection timing
· Defective fuel injectors
· Low cylinder compression

Low cylinder compression may be caused by leaking valves, sticking piston rings, ring wear, cylinder wear, or cylinder glaze. When white smoke occurs at cold start and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing.
Continuous evidence of white smoke indicates a mechanical defect, or incorrect fuel timing.

[lostmarbles]

Originally Posted by Greg_B

Statistical proof because I'm a papered mechanic with 1000 rebuilds under my sleeve and the laboratory in the back room. Nope, not me.

The HD mechanics at work have mentioned this, and have asked we put the trucks on high idle when parked at an incident. This is for electrical load concerns as well.

From conversations with diesel mechanics, as I pick their brains.

Filtered through reading and research.

I bump the idle too when wheeling and stopped for whatever reason (when I remember), and I would not turn it off simply to get out and check something. I understand "excessive" to mean hours and hours.

TheDieselStop.Com - www.thedieselstop.com

http://www.wjwatson.com/files/runningin.pdf (diesel generator info)

Get past the marketing, there is some good information...from your neck of the woods: Colour of engine smoke and when it occurs tells about internal condition

Marine diesel engines: maintenance ... - Google Book Search

Piston glazing and your "modern" diesel - Australian Land Rover Owners

Tonnes more out there if you want to read...








And...

Scary stuff here: Diesel Talk Forums - Glazing of cylinders read the de-glazing post. Yikes!

Wow. Tons of interesting reading there Greg. - Thanks.

But most of it refers to how bad it is to idle a NEW or RECENTLY-RECONDITIONED diesel. (Prolonged idling causes the newly-honed cylinder walls to "glaze" before the rings have time to "bed in".)

I still think that any diesel is far better suited to "prolonged idling" than any petrol engine. (Ignoring "running in" periods.)

But having said that, I agree that "prolonged idling" isn't good (in general) for any engine compared to "normal running".

(And I suspect we probably really share similar views on this Greg.)

I'm not really sure why I like to pull the "handle throttle a little" to increase my idling revvs. I think it is because I suspect I get better oil circulation doing that.

Anyway ...... I just wanted to dispell any suggestion that people should turn their diesels off whenever they stop (to chat to occupants of another vehicle they meet on a lonely track, or to check a river crossing or whatever). I reckon the wear on starter-gear would more detrimental if you were to do that.


PS. You just need to look around to see how many trucks and buses (all diesel-powered) are left idling for extremely-long periods on a regular basis (with no attempt at all to increase their engine-revvs either). ------ And I'm as guilty as anyone of doing this.

[canucksafari]

I always tell people to smell the smoke becuase far too often they mystake the colours - odor is a whole different ball game.

As for idling, I always idle up. If your truck has one, it's there for a reason. As for shutting down, I always do that a drive throughs and especially the border.

[9180ltd]

i have to agree with the idel up recomendations, i know most here havent come accross a detroit 6-71 before but if you have you would agree 2 fold. when those motors idel for even 1 hour they start to slober oil out of the exhaust and blow clouds of smoke on acceleration after

[canadian bum]

Originally Posted by Greg_B

There's been a lot of questions over the years about diesel smoke, and what the different colors mean. There have been some good data and input from different members.

Maybe the mods can look at diesel smoke FAQ.

Here is the main data from the NZ link, without the hyperlinks. I think it jives with what some of the more experienced and knowledgeable folks have mentioned. What do ya'll think.


SMOKE COLOUR

Basically there are 3 types of smoke emitted from a diesel engine: black, blue and white.

Black smoke:

Black smoke is the most common emitted from diesel engines and indicates incomplete combustion of the fuel. Black smoke causes can vary widely and include ..
· Incorrect fuel injection timing
· Dirty or worn fuel injectors
· Over fuelling
· Faulty turbocharger, or turbo lag
· Faulty or dirty exhaust gas recycling (EGR) system
· Incorrect valve clearance
· Incorrect fuel to air ratio
· Dirty or restricted air cleaner systems
· Over loading the engine
· Poor fuel quality
· Cool operating temperatures
· High altitude operation
· Excessive carbon build-up in combustion and exhaust spaces

Black smoke can occur across the entire operating range, but is usually worst under full power, or during the lag before the turbocharger boosts air supply to match the fuel usage such as in the early stages of acceleration and during gear changes. Moderate turbo lag smoke is acceptable; otherwise black smoke should be hardly visible in a correctly running engine.

Blue smoke:

Blue smoke is caused by engine lubricating oil burning. The oil can enter the combustion chamber from several sources including:

· Worn valve guides, or seals
· Cylinder &/or piston ring wear
· Cylinder glaze
· Piston ring sticking
· Incorrect grade of oil .. too thin and getting past rings, or valves guides
· Fuel dilution of the oil, making it too thin.

Blue smoke is often evident at cold start, which can reflect reduced oil control due to carbon fouling deposits around the piston rings and/or cylinder glaze. Blue smoke should not be evident at any stage.
An engine may burn oil without the evidence of blue smoke, because good compression burns oil quite cleanly, however, it is not acceptable for any new engine, or engine in good internal condition to burn large amounts of lubricating oil.

White smoke:

White smoke is caused by raw, un-burnt fuel passing into the exhaust stream. Common causes include:
· Incorrect fuel injection timing
· Defective fuel injectors
· Low cylinder compression

Low cylinder compression may be caused by leaking valves, sticking piston rings, ring wear, cylinder wear, or cylinder glaze. When white smoke occurs at cold start and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing.
Continuous evidence of white smoke indicates a mechanical defect, or incorrect fuel timing.

With white smoke don't forget coolant or water entering the cumbustion chamber. Most likely threw a blown head gasket but can also be a cracked liner/cylinder or head.

[Enigma]

From 'The Diesel Engine Reference Book (2nd Edition)'

Part IV, chapter 18

Exhaust smoke, measurement, and regulation.

[lshobie]

Just bought a BJ70, here is what was wrong:

Bad engine vibration on compression - ie. take foot off throttle, WHITE/Blue smoke on compression, bad smell like diesel but very rich. Rough engine running with eratic idle, idle would take a few seconds to come down. No black smoke.

Solution: New injection pump diaphram. Truck runs great now. No white/Blue smoke, no vibration, had to adjust idle and it is steady at all times.

[bvissers]

I just went on a 26 hour trip and ended up sleeping in my HD81 , it was cold so I left the engine running all night ( ~ 7 hrs ) when I got out for a nature call, I was surprised to see the amount of blue smoke comeing from the exaust. I upped the idle a little after that and the smoke all but disapeared, I agree with those that say these diesels dont like to rev low in the cold. As for black smoke, mine gives a good shot of black every time its throtled medium hard until the turbo kicks in good. Plan to tune that down a bit later.

[canucksafari]

Running for extended time on low idle is a great way to glaze your cylinders. When I drove MCIs we use to idle up for any stop longer than 5 minutes.

[lshobie]

Guys, diesels can idle for years. I had a BJ60 with the 3B, it came from the arctic and ran for almost 8 years straight with regular oil changes. The hardest part is keeping them warm in that environment. That truck had 360k kms on it last time I heard. Was always a strong runner.

I'd never worry about idling my cruiser.

[Greg_B]

Originally Posted by lshobie

Guys, diesels can idle for years. I had a BJ60 with the 3B, it came from the arctic and ran for almost 8 years straight with regular oil changes. The hardest part is keeping them warm in that environment. That truck had 360k kms on it last time I heard. Was always a strong runner.

I'd never worry about idling my cruiser.

Louis, have you read some of the links on post 15 of this thread?

gb

[canucksafari]

Originally Posted by Greg_B

Louis, have you read some of the links on post 15 of this thread?

gb

"add one teaspoon of abrasive cleaner" Man that's insane.

I am sure my cylinders were glazed when i first got my truck. Three years and nearly 100,000 kms later, the power is better and I have less oil consumption. I attribute that to lots of hwy travel at 110 kms/hr. The oil consumption is funny. It only starts at about 3,000 kms after an oil change. I'm not sure why. I'm guessing it is because of more soot suspended in the oil.

If idling, I set the idle-up to about 1400 rpm. If you want some load, turn on the AC.

[lshobie]

Yes I have read the post over quickly, my understanding is that glazing is what happens during improper break in procedures, if not properly broken in you will end up with glazed walls and oil consumption.

When I idle my truck I always idle high and so do guys up north - a low idle is not good and won't keep the engine warm. I also idle the fire trucks at high idle but that is for the alternator and lights as you mentioned.

Go to just about any truck stop and you will see truck idling for hours over night - nothing new there.

Maybe we should follow the mine truck method of break in, here it is:

From the first time you start the truck put it in 4 low and put the pedal to the floor and hold it there until the shift is over, then the next guy takes it and does the same thing. Do this for 10,000 hours and then rebuild. Or, in my engines case, 4200 hours of combined max RPM and long periods of idling, 24 hours a day 5-7 days a week. Change oil regularly.

I just checked my compression again about 30 minutes ago, all 6 cylinders are 600-620psi each. Not bad for idling all it's life

Regards,

Louis

[lshobie]

One thing that I will mention is that my new BJ70 I just bought, it was a one owner with 269,000kms on it. This guy brought it in every 5000kms to toyota for regular maintenance, if it needed something he got it, probably if it didnt he got it just because they told him to. Everything is very tight and mechanically it is great - except the blow-by. This old fella never had the truck over 100kms/hr and he only drove it about 10-15 mins to work every day in a 40-60kms/hr zone. So - it was never properly broken in and I suspect the walls are glazed.

I have been checking for oil consumption but all seems well for now. Will drive it like he did for a while and then slowly build up to the way I drive and see if that helps.

Louis