Outer Limits 4x4 Board

my mate has just got a lwb deisal mq ,it runs great but when he starts it up he says it blows alot of white smoke any ideas

It could be glow-plugs not working or some dead glow plugs in system. Injection pump timing could be retarded as well--might be leaking head gasket..

Nick

Leaky injectors? My old banger had a dirty switch in the glow plug system so when i glowed it it never really heated. so i'd stand on the gas till it started resulting in shitloads of smoke. Do you have to do that?

Have is compression tested, mine was low and the white smoke was a result.

Might be rebuild time.

White smoke is from unburnt fuel and can occur when the motor is cold.

Unburnt fuel in a cold motor could be due to one or more of the faults stated in the posts above.

Bush65 wrote:White smoke is from unburnt fuel and can occur when the motor is cold.

Unburnt fuel in a cold motor could be due to one or more of the faults stated in the posts above.

You missed a bit "when the motor is cold & low in compression or the glow is inoperative". A diesel shouldnt blow smoke at all when it is cold.

A mate of my dads bought one brand new & it didnt smoke when it was new but wonce it got to about 250,000 it srarted to get smoky in the mornings. It also blew black smoke when it was hot.

They are just about all buggered now, I saw one yesterday that looked like a smoke stack at Port Kembla.

They will ALL blow white smoke when Cold, ie. precombustion models if no pre heat .

Bazzle

my mate says it only smokes when its cold but after that its fine,the motor was supposed to have been reconed?.

what bazzle said.

My old truck did the same, try to glow the truck 2-3 times before starting to see if it makes a difference.


Dave

advance the timing!!!will get much better..(assuming glow plugs good and has good compression)

all deisels (non direct injection)new or old smoke when cold at start up.

mine smoked on start up real bad(embarasing) took to diesel speciasist they reconed injectors replaced glow plugs checked compression.no change.phoned another said ADVANCE TIMING..sorted!

My MK blows out a bunch of black smoke when i start it up... whats up there??

black smoke is usually unburnt fuel...? are your fuel/air mixtures too rich?

my MQ blows a heap of white smoke on startup, this weekend I'm going to replace my glowplugs... will put up a tech post with pics (SD33). it also takes about 20 seconds to glow, so i'm hoping new plugs will cure both these problems

what about when u blow out all blue smoke and a shit load of it on startup

black smoke......to much fuel or simply not burning it completely.

blue smoke.....oil. afaik if at startup either from breather or turbo seals.

white smoke.... improper combustion. can be a few things, faulty glow plugs, faulty manifold heater, faulty injector pump. incorrect timing.....one thing to watch here is faulty EGR systems, sometimes the timing is altered to 'fix' EGR faults.

tweak'e wrote:black smoke......to much fuel or simply not burning it completely.

blue smoke.....oil. afaik if at startup either from breather or turbo seals.

white smoke.... improper combustion. can be a few things, faulty glow plugs, faulty manifold heater, faulty injector pump. incorrect timing.....one thing to watch here is faulty EGR systems, sometimes the timing is altered to 'fix' EGR faults.

I have some questions about my SD33 since I just got it on the road. Trucks is supposed to have full rebuilt motor by p/o, I have reciepts. It blows huge clouds of white smoke for quite some time if I just let it idle to warm up, less time if I drive it to warm up. When cold it sounds like it is miss firing if reved. When warm this goes away. I took it out for it's first hard drive in 2-3 yrs today. Drove it up one of the steepest passes in the USA. It runs cool around on flats, up the pass it went up to about 2/3rds to "H" but never got much over half way to "H". Blew a small puff of black smoke all the way up the 12 mile pass, 10% grade. But pulled in 3rd at 60-80km the whole way, it has good power when warm. Coming down it cooled way down fast as I expected it would. I have tested compression on this motor when cold and it was low at about 375-380 average. I don't think I have a head gasket prob, I have blown them on petrol motors and this diesel just isn't showing signs of that. I had my injectors rebuilt and the truck has fresh diesel in it after old crap was drained.

So my questions are why would compression be low if it has full rebuild with low miles? I have reciepts from p/o for new head, pistons, rings, ect. Why would it blow smoke for so long at idle even when it is warm but not much out on the road? Small constant puff of black smoke normal pulling hard up a steep grade? Temp increases and range seem about right? Why would it sound like it misses when cold? Glow plug issue? If it has good power and revs well can we rule out some of the above posted reasons?

I am thinking it is either in injection pump or timing. Glow plugs may be contributing...but I don't get the low compression on a pretty low mile rebuilt motor. Other than maybe improper rebuild or excesive wear due to poor tuning?

while i hav't had it.....a fair few people have commented (on other forums) that recoing the injection pump has fixed their white smoke problems. as your getting white smoke at startup when warm then i would suspect the pump. i have no idea what was actually wrong with the pumps.

drop a line when you get it fixed.

zen wrote:advance the timing!!!will get much better..(assuming glow plugs good and has good compression)

all deisels (non direct injection)new or old smoke when cold at start up.

mine smoked on start up real bad(embarasing) took to diesel speciasist they reconed injectors replaced glow plugs checked compression.no change.phoned another said ADVANCE TIMING..sorted!

Being a total diesel n00b, I am just going to embarrass myself and ask: what timing on a diesel?

I have just always assumed that, having no spark plugs, diesel engines don't really have any timing to advance. What are we talking about here? Timing for fuel injection or something?

Educate me!

ignition is when the fuel is injected. advanceing the timing is to advance the point when fuel is injected.

older pumps you can rotate the pump body to adjust static timing.

i'm not sure but it think the pump itself changes the timing internally as well.....a bit like a dissy on an old petrol motor.

its a nissan, they blow smoke from day 1!

I have a GU 2.8, and it will start from cold straight away as long as I give the glow plugs their set time, however say if it's let to cool for a while maybe about an hour and I go to start it and try to start a a second to early and it will take ages sometimes I have to clutch start it and when it does fire a ploom of white smoke comes out, I had all six glow plugs replaced about two years / 40000kms ago when it wouldn't even start after full glow time. Any ideas.

tweak'e wrote:ignition is when the fuel is injected. advanceing the timing is to advance the point when fuel is injected.

older pumps you can rotate the pump body to adjust static timing.

i'm not sure but it think the pump itself changes the timing internally as well.....a bit like a dissy on an old petrol motor.

Pump timing my friend. Smoke on start up can be worn valve stem oil seals which are nothibg to worry about.
Alex

My 3.0 GU with 140,000km on the clock started getting harder to start in the morning since its gotten colder , with a small missfire for 5-10 seconds and a bit of white smoke out the back , ripped out the glow plugs and put a new set in , good as gold. starts first kick and runs smooth as , no smoke.

i would start with checking the glow plugs are getting power to the rail and find out how long they glow for (my timers not working on mine), if all is good there take the glow plugs out and test them,
many faults can cause this

Harms , does yours still have the split plug style glow system , where the back 3 are on a different rail to the front?


"MKPATROL - They are just about all buggered now, I saw one yesterday that looked like a smoke stack at Port Kembla." LOL! X 1000 i owned a 24 volt sd33 it had been around and was back to 390,000... weapon. it was port kembla... just learned to live with it and its 2 litres of oil consumtion a week

IN24BZ wrote:Harms , does yours still have the split plug style glow system , where the back 3 are on a different rail to the front?


"MKPATROL - They are just about all buggered now, I saw one yesterday that looked like a smoke stack at Port Kembla." LOL! X 1000 i owned a 24 volt sd33 it had been around and was back to 390,000... weapon. it was port kembla... just learned to live with it and its 2 litres of oil consumtion a week

, my old girl is long gone, had the GQ for 5 years now (much better in every sense) but yeah she was a smoker thats for sure, You should have seen it when I was up the mountains.

One of my mates spoke up on the CB one day & said "Hey Browny, your car is on fire...."