white smoke

[rlvelin]

I've been a member to this site for one whole day and have already aquired a ton of good advice and knowledge. I've looked at the previous posts and the troublshooting page for white smoke problems and have started doing some preliminary troublshooting, however I am hoping in the mean time that someone knows a little more about my specific problem.

Just bought a '93 K2500 6.5L with 189,000 mi a month or so ago, in the last week I've noticed an increase in white smoke at startup and during engine warm up to full operating temp. I found that the cold advance temp switch was bad and replaced it, now there is only small puff (normal) at startup. At about 1500+ rpm in nuetral, 1st and 2nd gear the smoke pours out and a hesitation/miss is experienced until I shift or rpm is reduced to less than 1500. Also during deceleration or engine braking puffs of white smoke are emitted. This occurs until engine temp reaches about 180+ degree F.

I've looked at the injection pump timing, the scribe mark on the pump is about 1/8 inch to the right of the mark on the timing cover as looked at from in front of the rig. I believe this is an advanced condition but am not sure. When timing is adjusted to line up the marks the white smoke condition gets worse. I am not able to rotate the pump further in the other direction as the throttle cable bracket is already up against the coolant duct. I replaced the fuel and air filter when I bought the truck and it ran normal with those components until recently.

Thanks in advance for any help or advice on specific checks I should do.

[DmaxMaverick]

rlvelin

Welcome aboard! You are definately in the right place for answers.

Your problem is pretty basic. White smoke indicates raw fuel. First thing that comes to mind is glow plugs. A few failed glow plugs will cause white smoke and stumbling on a cold engine. Have a good look at the plugs and confirm that they are cycling properly and are not fried.

With 189K on the clock, a few other things could be suspect. If the timing chain/sprockets haven't been replaced, they are overdue. The timing chain will stretch over time. The pump can be adjusted to compensate for the fuel timing, but after the chain is stretched too much, the valve timing will be so far off that pump timing doesn't help any more. If you plan on enjoying your 6.5L for a long time to come, or intend some performance mods, have a close look at a timing gear set, as opposed to the stock chain/sprocket set. A little more money, but well worth it in the long haul.

This is not all the possibilities, but a place to start. Let us know how it turns out.

Good luck

[rlvelin]

You confirmed one of my suspicions, the timing chain stretch as possibly indicated by the adjusted injection timing. Not knowing much of the maintenance history of this truck I had planned on checking out the timing chain on the next oil change and replacing with a gear set as well as replacing the leaking front main seal which brings another question about.

I have heard and read that engine oil is no good for the rubber in the harmonic balancer which mine usually has a nice film covering it. Is there a way to determine if the rubber in the balancer is damaged or should it just be replaced in order to avoid a serious crank catastrophy? Any suggestions as to where to look to find a good quality, fair cost replacement?

[Johnny B.]

Just did my timing chain set and harmonic balancer.

Timing chain set $124 Napa
gasket set $12 Napa
Harmonic balancer $96 Pronto special order

You might want to consider replacing the crank pulley, I have noticed some vibration in mine and will replace it soon.

[BigMikeO]

Originally posted by Johnny B.:
Just did my timing chain set and harmonic balancer.

Timing chain set $124 Napa
gasket set $12 Napa
Harmonic balancer $96 Pronto special order

You might want to consider replacing the crank pulley, I have noticed some vibration in mine and will replace it soon. Johnny B

How much work and time was involved with those replacements you did. I have 170K miles on my truck and was thinking about those same replacements.

[ucdavis]

Harmonic balancer check is a close visual inspection which may not be practical if covered w/oil. You'll be yanking this when doing the gears, so you can do a good clean & check. But, if you have no info on the balancer mileage, if it was me I'd replace it anyway. You're there to start and they are not friendly when the rubber inserts crack. Previous experience here indicates 80,000-100,000 for a decent lifespan, then change it for a new one.

[Johnny B.]

Big Mike plan on spending 8-10 hrs including cooling mod total time for you probably less. The most difficult part of my job was updating to the 97 cooling mods, that is where I had my problems. I spent 4-5 days on the project between running the kids to and from school, work , mowing and everything else.

The first thing I did was degrease the engine, inside the engine compartment and the front suspension. Since I have a digital camera I shot a few images as work progressed my memory is not perfect.

Someone here had a good idea as to draining the radiator. Drop a hose into it 5'-7' in length and drain the radiator into a bucket, worked like a charm.

I didn't notice what year you have, but after adding the dual thermostat cross over I had one heck of a time tightening the 3 bolts that mount the mechanical IP.

I used the wrong type of puller on my harmonic balancer so you can say I destroyed it :D ! I noticed quite a bit of dry rot on my crank pulley, wife said I already spent too much money, I heard about it again today.

When I got to the chain and gears I notice some slop. So I would say you can only benefit with a new chain and gears. I use my truck as an inexpensive tow vehicle for our travel trailer and boat I couldn't justify the $300+ for the gearset, you might consider it. Don't forget to have a tube of RTV on hand. Good Luck with yours!

[rjschoolcraft]

Just a thought from another direction...

The way you described the white smoke and stumbling and when they occur lead me to believe that you might have a head gasket leak or other problem that is allowing coolant into the combustion chambers. Hope not.

[rlvelin]

The way you described the white smoke and stumbling and when they occur lead me to believe that you might have a head gasket leak or other problem that is allowing coolant into the combustion chambers. Hope not. Could this be checked by observing if there is a drop in coolant volume or a compression check or any other method other than pulling the heads?

A couple more observations that I hope indicate a stretched chain. The smoke definetly smells of raw fuel, it gets more blue in color as the engine warms up and if the engine is under more of a load such as driving in 3rd or o/d or going up hill the amount of smoke decreases or even ceases. Also there is a barely noticable amount of the white smoke seen exiting the oil fill with the cap removed, is this normal blow by? This was only seen when the engine was cold I have not checked it yet after the engine has reached operating temp.

Either way I'll be replacing the timing chain/sprockets with a gearset this weekend and probably the balancer as well. I'll see if that does the trick.

[rjschoolcraft]

You should see some consumption. Also, you should see pressurization of the coolant system.