300Tdi smoking when cold

[nas90tdi]

I have a little situation a fair ways from home, so hoping to get a little closer to diagnosing what is causing the issue. Before I attempt the 300 miles over a mountain range back to western Washington.
When the truck is cold, it billows white smoke when engine braking at low speeds and low rpm. Blip of the throttle lessens it. Once it's warm it's right back where it should be. Slight black haze under acceleration. Smoke smells of unburned diesel to me. Though it could be oily smelling just a bit. Haven't been where I could really get a good whiff and it doesn't do it at idle.
300 Tdi. Mileage unknown. Bought it from Doug, he was told about 140k. No evidence to suggest otherwise when I installed it. Valves adjusted 2500 miles ago. New timing belt at the same time.

Before anyone asks what the compression is, I can't say. I am in a town of about 1000 people deer hunting and don't have my compression tester. So, can't say what it is.

Engine runs exactly as it always has. Starts at the touch of the key. Good oil pressure. No oil contamination from coolant. Coolant level stable ,no evidence of bubbles. No odd temp readings. EGt's normal. Highest I have ever run them is 1100F. I ran them at about 1050F for a good bit yesterday coming over the pass. Boost pressure same as always.

I honestly have no evidence other than the smoke that anything has changed from everyday when I drive it. No odd noises, pulls just like always.

I am thinking it is some sort of fueling issue. It's like it's dumping excess fuel when boost is 0 and riding on the engine downhill. Any throttle that builds boost lessens it. But, I can't figure why it would be engine temp dependent.

Ideas?

 

[RBBailey]

You're much more brave than I am!

Is this a new thing? Mine has always smoked white when cold. I always drive down a hill for the first 1/2 mile, and if I forget and use some throttle, I lay a smoke screen across my neighbors' driveways. It does not smoke when engine braking, but it does puff a bit at idle. It smokes a lot when given gas.

However, this all goes away within a mile of driving. I then have dark smoke when gassing it before the turbo spools, or a haze of smoke while using about 80% or more power at speed.

I've been told that this is all normal. But I have noticed a bit more smoke just in general driving.

I think we are seeing about the same thing.

 

[Uncle Douglas]

Fuel issue. Last filter change ? Have you replaced injector tips ?

 

[nas90tdi]

Thanks Doug. That is my guess to. Filter is from when I installed it after I got it from you. So, about 2500 miles.I have more with me, I will swap that in the morning.

I have been thinking about swapping the injectors. So, no. They have never given me any issues. I just figured they were pretty worn. Almost called Robert a couple of weeks ago to get some. Maybe I should have.

RBailey, no definitely new. Mine has never smoked white. Maybe a puff or 2 on occasion when I crank it. But, nothing abnormal. Freaking thing is laying out a smoke screen now though. Freaked me completely the hell out when I caught that in the mirror when I started down that first hill. It might have done it on the way out, but that was at 5Am on a dark road. Unless I would have had my rear fogs on, I wouldn't have been able to see it as no one was behind me.

 

[RBBailey]

I am getting mixed signals on this. Not sure what to think.

If I were you, I'd probably drive it back. But if you've payed any attention to my posts, you should probably do exactly the opposite of whatever I do.

My injectors are new, the fuel filter is going to be changed when I get the chance, maybe tomorrow if I can find one in town.

 

[nas90tdi]

I am almost definitely going to drive it back. I just wanted some input on whether I was seeing the problem correctly and hadn't missed something. Like it was about halfway across the North Cascade Loop from imploding because I had mis diagnosed. I feel a little better since Doug sort of echoed what I was thinking. My biggest problem is I actually know all the ways these things can go wrong ,so I start second guessing myself after a whole day to think on it. I have always done all my own work, so start trying to decide what I might have screwed up. With a whole day I had already mentally pulled the head off another engine I have and rebuilt it and done all kinds of other stuff. I am worn out from all the mental mechanic work on a stupid Rover I have done today.

 

[RBBailey]

If it makes you feel better, I'm debating pulling the entire fuel system out tomorrow, tank, lines, and all up to the filter in the engine bay..... it's either that, or hope the thing doesn't break on me before I can get the RRC towed to the shop and back up and running. I'm just glad I got it running enough to get home earlier this evening.

Let us know how this progresses. I'd like to think I could start the car and not have it doing the white smoke some day.

 

[RDavisinVA]

I have found that white smoke can be caused by emulsified water, but in your case it would be more consistent.
Are you running a sedimenter and 12V low pressure fuel pump?
You could use a new fuel filter.
White smoke on overrun and when cold is generally due to a lean mixture.
Have you had an algae infection at any point?
If you're running the shitty old plastic lines, they are known for causing issues when kinked, split, or have rubber hose slipped over them.

 

[jymmiejamz]

FWIW, I think my 300 Tdi did this when cold. I never did anything about it.

 

[Red90]

The white smoke is unburnt fuel. You get unburnt fuel by having some of it injected too late in the cycle or from one or more pistons not igniting.

When dead cold, it is common to get white smoke due to a piston not being hot enough to ignite and it clears once you get going.

In this case, it is more likely the timing is bit retarded or you have a poor spray pattern.

There is no worry about driving it. Nothing will be damaged. When you get back, check the timing. It is best to use the dial gauge method. If that does not fix it, pull the injectors and get them checked or replaced. Mr. Davis sells new ones at a great price.

 

[Uncle Douglas]

Injector tips are a wear item on these engines.Manual calls for them to be replaced @ 80k intervals. Most of us drive them until we have to have them. That said these are two stage injectors and the internals do wear, so taking them to an injection shop to be checked out is always a good plan. My guy (same guy Robert uses) charges me $10 an injector.
Are you running any type of diesel treatment ? I dump a bottle into my 418k mile 99 f250 every once in a blue moon and it makes a noticeable difference.

Our fuel here is fairly low quality compared to Europe. They have three grades of diesel @ the pump and the lowest octane gasoline is 95.

John nailed it that your timing is either off or spray pattern isnt right.

 

[DefendersNW]

John nailed it that your timing is either off or spray pattern isnt right.

Also he went from sea level to likely 6K-7k feet so if adjusted for home, the truck will be running rich.

 

[nas90tdi]

I can completely buy the injectors being worn and just dumping fuel into a cold engine that can't burn it all. And, I was putting off injector service while doing other things since those were behaving. That may be at an end.
Not as much a believer in the timing being off. I set it when I swapped the engine in, and besides the billowing smoke while engine braking cold no other issues? I can't see it. Timing off would express itself in other ways as well, not just one. I will check it when I get into it, but unless someone can say that timing being off only causes one issue and absolutely no others, I say the timing is still on.

I thought about Brian's idea to about the elevation change. I was only at about 3k when it did it, but in much drier air then the truck is used to running on. So, it was running on much less dense air. I know I have seen the EGT differences on a lot of my trucks based on air density, so it definitely makes a difference.

Anyway, made it home with no issues and except for the weather deciding to throw a snowstorm, and those daft wipers deciding to push a wad of ice back and forth in front of my face every 10 miles.. No sweat.

 

[Uncle Douglas]

Very cool picture.

How do you define timing being off ? The IP pully allows for 3mm of movement. Its not uncommon for small adjustments to be made there over the years to compensate when changing timing belts. Fly wheel make lock. IP pin may slide in, and timing still be off.

 

[nas90tdi]

My brother jumped out and took that from the middle of the road. Not like any one else was up there. They had the brains to stay home during the foul weather we are having.

That is my understanding as well. Even setting it with my gauge , I am not saying the new belt may not have stretched a bit and gotten a tad off. My statement is more along the lines of a sudden shift in behavior in only one aspect. But all other indicators of the timing being out not being present. I very well could be wrong about that. I just know you will usually see some other indicator of the timing being out. And, I really can't say I am seeing them.

Honestly, this engine I got from you may be the very best running 300 I have ever dealt with. And, really has been from the first start when it was still sitting on the floor on a pallet. I fired it off before I even started swapping out all the wear parts and seals before I put it in the truck.

 

[Uncle Douglas]

how long does it take you to pull the softop and cage to run that top for winter ?

 

[nas90tdi]

It's not terrible. I can have the cage off in under an hour. That's not including if I take the bulkhead feet off and if the bar behind the seat does't decide it needs a Highlft to get it moving.
Hardtop is pretty quick as well. I had my truck cab on last winter, but I am 6'3" ,so you know the issues that presents.

I am most likely not going to take the hardtop off again I have decided. I bought Tomacos old doors and completely rebuilt them so I have roll up windows now. I think I am done with the top swapping for a bit. It's funny how the things you like change. I used to love the half doors. I even put them on my 95 NAS SW. Now, they just drive me nuts. Though I was living in Texas at the time, so the door tops stayed off for months. I felt like I was taking them off and putting them back on all the time here in Washington. I have made some seriously cold trips home in the middle of summer because I didn't have those door tops with me.

 

[nas90tdi]

Just to close this out.
Checked timing. Wasn't off. Reset with my dial gauge anyway just to make sure.
Sedimenter cleaned. Fuel filter changed. Algeacide ran through tank, Didn't find water in either. I did however drain the sedimenter in the hotel parking lot in the dark before I headed home. Didn't catch any water in my cup but also ran the first shot down my arm to the armpit in the freezing cold. That well could have been the water.
Haven't been able to replicate the condition even in freezing temps since.
I replaced the injectors just because Robert was so happy to send me some. No change except its a tad louder at idle and a tad quieter at speed.

So, I am writing it off as a fluke and figure I had some water run through the thing. Hell of a lot of smoke though. I am glad I was in the woods instead of in town.

 

[RDavisinVA]

Glad you are up and running smoothly.
Running out of the cheaply priced Bosch injectors.

 

[Uncle Douglas]

who ?