1974 W115 240D White Smoke Issue

[DESI4x4]

Hi All,

Thanks to the input from many of you, i got the engine running, also thanks to 'shelter in place' by our county... COVID-19 special...

Background:
- Purchased a 1974 W115 240D that sat for 10-15 years
- Removed the engine and refreshed it with all new gaskets, o rings and crush washers
- Now, it starts first time (after using the glow plugs); the engine is still outside to facilitate easy IP adjustment

Checked:
- IP timing, at 24 Deg (Drips one drop per second)
- Injectors pop pressure (all of them around 1666 psi). Yes, i purchased injector pop tester.

Problem:
- I turn the glow plugs on for few seconds and fire it up. I starts first go... but, there is white smoke...

Any suggestions? the engine is still outside, so i can work on it easily.

Thanks in advance.

[Diesel911]

put a piece of card board near the Exhaust and see if it smells like Fuel.

If it smells like Fuel and the smoke is extremely white you are looking at unburned Fuel.

When I had that happen on my Volvo Diesel I had the timing too retarded. I got billows of white smoke out of the exhaust.

Advancing the timing fixed it. Lock and see if there is any reference marks on the Block to Fuel Injection Pump flange area. If not scribe or other wise mark across the Block and Fuel Injection Pump flange (this is also so you can return it to the same place if what I am going to say does not work). Loosing the Fuel Injection Line Nuts at the Injectors and loosen the Fuel Injection Pump Flange Nuts and rotate the Fuel Injection pump no mire then 1/16th of an inch at a time and see if you can advance the timing enough to get rid of the white smoke.

[Diesel911]

I am trying to attach a pic of the timing specs. One of the 615 Engines times at 26 degrees before top dead center. Don't know which one you have.
Also the Fuel Injection Pump Throttle Lever is I believe supposed to be at full fuel when you do the timing.

[DESI4x4]

I have the OM616.916 W115 1974. The odo has 36k miles, but may have gone over once... Absolutely no rust on the car.
I will work on it in the morning and do as suggested. Will try advancing the timing as well.
Thank you.

[Diesel911]

Originally Posted by DESI4x4

I have the OM616.916 W115 1974. The odo has 36k miles, but may have gone over once... Absolutely no rust on the car.
I will work on it in the morning and do as suggested. Will try advancing the timing as well.
Thank you.

I don't know if in 1974 the Diesels had a sticker with the timing specs on the sticker.

[DESI4x4]

There are no stickers on the car that i can find.
I am following the Internet FSM for OM616.916.


One more thing, when it smokes, it burns my eyes and have to open all garage doors!

[Alec300SD]

Definitely unburnt atomized fuel from your description.

Maybe the IP was installed out of phase.
Surprisingly these engines can run, albeit poorly, when the IP is timed to the wrong compression event (exhaust instead of intake).

[vwnate1]

Remember : you're running a long dormant engine in a test stand .

Button it up and re install it, once you're able to drive the darn thing you may well discover the smoke clears op after some road driving .

[Screwdriva]

I have a similar issue but with dark grey smoke on startup. Also smells burnt. This only happens for the first 5 minutes. Then the smoke reduces by 80% or more.

[DESI4x4]

Originally Posted by vwnate1

Remember : you're running a long dormant engine in a test stand.

Button it up and re install it, once you're able to drive the darn thing you may well discover the smoke clears op after some road driving.

I ran it for 20mins yesterday in the driveway (with water connected), but no change. Neighbors thought that I was doing the Corona fumigation .

[DESI4x4]

Originally Posted by Alec300SD

Definitely unburnt atomized fuel from your description.

Maybe the IP was installed out of phase.
Surprisingly these engines can run, albeit poorly, when the IP is timed to the wrong compression event (exhaust instead of intake).

I double checked it that i was on compression stroke... Will check again this afternoon when i fire it up.

[DESI4x4]

Originally Posted by Diesel911

put a piece of card board near the Exhaust and see if it smells like Fuel.

If it smells like Fuel and the smoke is extremely white you are looking at unburned Fuel.

When I had that happen on my Volvo Diesel I had the timing too retarded. I got billows of white smoke out of the exhaust.

Advancing the timing fixed it. Lock and see if there is any reference marks on the Block to Fuel Injection Pump flange area. If not scribe or other wise mark across the Block and Fuel Injection Pump flange (this is also so you can return it to the same place if what I am going to say does not work). Loosing the Fuel Injection Line Nuts at the Injectors and loosen the Fuel Injection Pump Flange Nuts and rotate the Fuel Injection pump no mire then 1/16th of an inch at a time and see if you can advance the timing enough to get rid of the white smoke.

Also, forgot to mention, this car came with two injection pumps. One had a broken hole for the rear nut that fixes it to the engine. So i tried both pumps and i have the same result under same conditions, white smoke.

Also, I removed and cleaned the pre-chambers again, new washers, new injector washers, etc.

You are correct, since it's same with both pumps, I will start advancing the timing today and report back.

[DESI4x4]

Originally Posted by Screwdriva

I have a similar issue but with dark grey smoke on startup. Also smells burnt. This only happens for the first 5 minutes. Then the smoke reduces by 80% or more.

This happened to my 1996 Mitsubishi Pajero V6, and when i changed the valve stem seals the problem went away...

[DESI4x4]

OK Team, I went though the setup and did the following:
- Clocked the IP towards the engine by 1/16th of an inch at a time and its pinging or nailing
- Clocked the IP away from the engine and the smoke is turned blacker...
On a general note, the RPM seems high.
I took a video and try to upload it later today.

[DESI4x4]

Video of the engine running today after tinkering with the IP. This is the beat i could get to. Please see the smoke.
https://youtu.be/efC09R-Rm40