Archived white smoke problem update.

[ranger71]

Just wanted to update my earlier post. This morning I started the truck again, fired up with just a bump of the key. Still white smoke. Figured I'd replace the fuel filter, no difference. Lift pump worked fine at least manually to fill the fuel filter canister. Pulled out the pump overflow valve and dismantled it, cleaned it and reassembled everything, still no dice. Will a motor with oil starvation damage still start reliably and run with the white smoke problem and a little vibration? Seems like there would be other issues, hard starting, horrendous noises etc? Anyone have any ideas? I wish I could tell you fuel pressures and boost numbers but it's a stock truck and I don't have the equipment to test these things. Thinking I'll pull the exhaust off the turbo and see if there's oil in it but I think it must be a fueling issue as the smoking starts right off the bat when the truck starts from cold. Wish me luck with that exhaust clamp, it hasn't been touched in seventeen years... Thanks in advance for any responses!!

 

[petersonj]

Just some thoughts. If one cylinder had very low compression, it could produce white smoke and the engine would vibrate because one cylinder would not be carrying its share of the load. If you loosened an injector line one at a time (while the engine is idling) you could observe which cylinder is not doing its job and see if the white smoke momentarily stops.

Also, you could remove the valve cover, bar the engine over by hand, and observe valve clearance and the height of travel of each pushrod. This would let you know if you have a camshaft problem or a valve train problem.

- John

 

[ranger71]

Hey John, Thanks for the reply, I'd read about that procedure but hadn't made the link to the smoke going away when you find the low cylinder. Off to try it right now. reckon it's better to loosen at the pump or on top of the injector? Thanks again for the advice.

 

[Killgore]

I hate to ask this question, but how many miles have you got on the injectors? I had a bad solenoid and similar issues.

- Ed

 

[ranger71]

I'll try and be brief

I bought the truck in 2000 and it's done 415k with just oil changes, front hubs, brake rotors and that fuel shut off solenoid you mentioned. also the occasional starter and alternator. I pulled the injectors for the first time in seventeen years yesterday and dismantled them, cleaned up the tips and bodies inside and out but the surprising thing was that every one of them had five clear spray holes and the needles inside were super clean also. I need to adjust the valves as,you know, its been seventeen years... But I'm afraid I cooked the rings driving without enough oil. I got a bad reading on the dipstick, always check both sides... I've never given this truck to a mechanic except for clutch jobs but on Wednesday I'll check it in for a compression test and see what they say, local shop has good as well as terrible reviews so who knows if it's even worth the $120 they're asking. Thanks for your interest, any genius ideas send them my way as I'm up that creek again!

 

[petersonj]

reckon it's better to loosen at the pump or on top of the injector?

Loosen fitting at the injector.

- John

 

[ranger71]

So I tried bleeding pressure off individual injectors and honestly there was no dramatic difference, its pretty amazing how little the motor seemed to care. I just pulled the exhaust off the back of the turbo and found only soot, no liquid of any kind so I think I can rule out turbo seals. I think it's either low fuel pressure not atomizing the injector spray well enough for good combustion on any cylinder or low compression on all cylinders again not providing good combustion. I'm going to see if I can find a compression tester at hazard frought tonight as I can't really trust the local shop to be honest, apparently some customer reported that they told him he needed new heads on his duramax and he'd had them replaced five months prior to bringing it in. not getting the warm fuzzy feeling.

 

[petersonj]

The results of the test could be a good sign that those high mileage injectors are very tired and have very low pop-off pressures. Hope the compression check comes out okay.

- John

 

[GAmes]

My original injectors had more than 400k miles on them when I replaced them The issue wasn't white smoke, it was black smoke and poor mileage. So much fuel had been pumped through them that the holes had enlarged. The local Bosch shop tests stock injectors for free, so I took them in. Pop pressure was still good and they didn't leak.

When you sat you ran it low on oil was it off the dipstick or just below the low mark?

 

[ranger71]

Not off the dipstick but about an inch and a half up. I’d checked it a couple days prior but think I got a bad reading as it happened again after. I dipped the stick and it looked good then I flipped it over and oh boy...you’re probably right about the injectors failing the same way, all the holes were clear and the internals were really smooth, kind of amazing when you think they’re on their way back from the moon! Going to check cylinder and fuel pressures tonight.

My original injectors had more than 400k miles on them when I replaced them The issue wasn't white smoke, it was black smoke and poor mileage. So much fuel had been pumped through them that the holes had enlarged. The local Bosch shop tests stock injectors for free, so I took them in. Pop pressure was still good and they didn't leak.

When you sat you ran it low on oil was it off the dipstick or just below the low mark?

 

[ranger71]

Ok, so I just tested my fuel pressure, couldn't find a kit to test the compression yet but maybe I've found a problem. At idle the pressure measured at the supply line banjo bolt on top of the filter canister was 38psi, at 2500 it was 40psi. Could this high pressure be the cause of my white smoke? I'm getting pretty desperate here, need my truck for work pronto!!

 

[ranger71]

I havent checked the screen that I believe lives next to the fuel heater, is that my next stop?

 

[GAmes]

Lot of people run that high of pressure, some more. That isn't it.

While you are checking the screen remove the fuel heater that is just above it and pitch it into the trash. It is unneeded and the source of many hard starting issues. The screen housing will then fit into the threaded hole the heater was attached to.
http://www.cumminsforum.com/forum/94-98-engine/58777-joe-gs-fuel-system-writeup.html

 

[ranger71]

So much for that. What happens when the screen gets plugged up? Low fuel flow? I think I'm either getting too much fuel or my compression is too low to complete combustion, I pulled the oil filler cap and I've got a bit of a tea kettle situation going on. I don't know how much blow-by is too much but I definitely have it.

 

[GAmes]

If you had too much fuel or low compression the result would be black smoke which is unburned fuel. This isn't a gasser, fuel to air ratios change constantly with no ill affects. The screen being clogged would give you low fuel pressure, but it wouldn't hurt to clean it out when you toss the fuel heater puck. A simple manometer can be fabbed up for a few dollars, but I doubt that blow-by is your issue.

 

[B.G. Smith]

Are you losing any coolant? bg

 

[ranger71]

So now it looks like on top of everything else the motor is going through oil at a pretty good rate. I added oil when I initially started looking at the smoking issue and just for kicks I checked it today and it was low on the dipstick again. I know of some leaks and reckon they’re to blame as it’s gone through two quarts or so just with me running it the little I have trying to diagnose things and I figure if it was getting burned I’d notice it at the turbo down pipe which was dry and just sooty. It rained all last night and all day so it’s hard to tell where it’s all going.

 

[ranger71]

Coolant level is all good, seems to be going through oil pretty fast however. I’m trying to adjust my valves but with the dowel pin blocked it’s not easy to find TDC, I need a dial indicator for sure.

 

[GAmes]

It's easy to find TDC and you don't need the cam timing pin or a dial indicator. Pull off all the valve covers. Rotate the engine in it's direction of rotation watching the #6 rockers. When the exhaust valve closes and the intake starts to open the (valve overlap) #1 is at compression TDC. Adjust the valves as outlined in the FSM, then rotate the engine one full turn. #1 will be at valve overlap and you can adjust the other 6 valve's lash.

You really need to remove the injector pump and fix the tappet cover leak. Until that happens you will be chasing your tail.

 

[Missouri Mule]

Where are you located north, South or in the middle some Where? Is the ctd in side or out side?