85 300D smokes too much! Billowing clouds of white to gray smoke on start up, diminishes considerably when warmed up, but will put out quite a cloud if i punch the accelerator, or drive up a steep hill.

Car has about 200,000 miles. It has run about 35,000 miles on unheated WVO with a little gasoline, in warm weather only. I use only thin decent oil not cooked to death, filtered to 1 micron, and have had few problems. I regularly add some transmission fluid, and Diesel kleen.

Compression is about 300 p.s.i. in all 5, but nevertheless, i have switched to Kerosene /diesel now that the weather is cooler, and also did a week long Marvel mystery oil soak. I used almost the full quart, and cranked the engine a bunch before putting the injectors back. I had previously disassembled and cleaned the injectors as per one of the procedures elsewhere on the forum. They were quite clean internally, but had some crud in the pintle area. Soaked the bottoms of them in M.M.O.while the rings were soaking.

I'm thinking the M.M.O. probably seeped past the rings into the crankcase, and not sure to run it a while before changing the oil to clean out sludge etc., or if i should change the oil right away. I read somewhere to add a qt of tranny fluid to the crankcase oil and run it about 50 miles.

I also changed the spin on fuel filter, and checked the fuel in the old one for moisture, but no visible sign of any. Tried removing the air filter, no difference.

Smoke seems to have diminished a little since the M.M.O. soak.

Car starts a little uneven at first, but idle evens out in about a minute, and she has reasonable power, maybe a tad slow on the uptake if up a hill, especially when not fully warmed up, but i am going to change my tranny fluid filter to eliminate that possibility.

Read about disabling the EGR, but not sure how to do that on a trial basis. Just disconnect two vacuum lines? Where would those lines be, and do they need to be plugged?

I am trying to eliminate everything i can without sophisticated tools before i bite the bullet & spend $200 on new injector nozzles.

Thanks so much for all the awesome advice this forum has provided.

As you surmised, the MMO has made its way into the crankcase. Change the oil. If you want to defeat the EGR you can plug the vac lines, but a better solution would be to remove the EGR & install an EGR delete plate (simple two bolt install).

As for white smoke, are you using/losing coolant? Quite often white smoke on start up indicates coolant getting into the combustion chamber. On the other hand, is there any chance that you are getting moisture/water in your WVO fuel?

Mine did the same thing until I changed out the nozzles. Bite the bullet and change them out.

I am looking at a round thing at about the 5:O'clock position just below the air cleaner, with a corrugated aluminum pipe running downward. It is attached by 2 hex socket bolts, and has One vacuum line. I am assuming this is the EGR valve. There is another protrusion below about the 6 O'clock position of the air cleaner with a vacuum line.

Do i disconnect BOTH of these vacuum lines and plug them to test the effect of removing the EGR valve? If this works, i would then unscrew the two hex bolts and install a metal blocking plate?

I've been pretty careful about moisture in the fuel. I let it settle for months and very carefully decant it into a "pre-bucket" before pouring it thru my filter. One time a drop of sweat dripped into a 5 gallon bucket of WVO, so i added 1/2 bottle of Heet dry gas. In any case, i am now running diesel/kerosene and there is very little WVO left in the tank.

No noticing any loss of coolant.

As for changing the oil, i am tempted to throw in all or part of a bottle of tranny fluid, run it 10 - maybe 50 miles, then change the oil. Good or bad idea?

Pelican is getting $38 ea for the nozzles. Any substantially better deals out there? I guess i should support Pelican tho, the forum alone is priceless!

I just blocked off vac line with a screw,,as far as smoke mine will smoke white when cold,its unburned fuel.You may have 2 glowplugs out.New injectors will help a bunch too.

MMO in your oil isn't a problem, especially for that small amount of time. In fact you'll probably notice that it starts easier when cold. But if it dissolved a bunch of crud and took it down into the oil with it then I certainly wouldn't run it forever. Also, check to see that it hasn't increased the volume of oil according to the dipstick. It may not have, as it does evaporate, but you don't want the classic runaway caused by too much oil.

-Rog

Pulled the vacuum line off the EGR, and plugged it. Got a big puff of Black smoke when i started it. Smoke was a little less driving, but black rather than whitish grey. Baffled!

Still starts readily, but rough idle for the first minute or two.

Checked glow plugs, all tested OK. Added about 1/2 qt. of tranny fluid to the engine oil (along with whatever M.M.O. may have seeped past the rings when i did the week long soak).

Planning to drive about 30 miles and change the oil.

Seems to run maybe a little better, certainly no worse.

I'm thinking the grey smoke was a mixture of white and black, and disabling the EGR made the white smoke disappear, but added more black smoke.

What should i look for next ? Anything else to check before i spring for Injector nozzles? And would injector nozzles cause black smoke? How much would that impact fuel mileage?

Thanks again!

Put the EGR back. It has nothing to do with this problem.

The problem is that you are drawing oil through the intake tract. Why is the question. Unfortunately, I don't have a 123 to refer to, but there are two usual sources: turbo leakage or the crankcase breather. What you want to check first is the crankcase breather. Whatever arrangement the car has for drawing blowby gas into the intake, there should be an air/oil separator...look for oil there. Check to see that your air filter isn't obstructed, blow out the element. Then pull the breather hose from the front of the turbo and check to see if it's wet with oil.

Do your testing with Diesel Fuel.

Someone might have already mentioned this. A different type of Fuel Injection Pump. But, when I installed the Fuel Injection Pump on my Volvo Diesel I got billowing clouds of white smoke at idle.

It turned out I had the timing too late/retarded and I had to do a better job with the timing and that fixed it.

If is late timing the white is caused by Fuel Droplets. If you put a piece of Carbard near the Exhaust and let the smoke get on it for a while if it smells like Fuel that is evidence of the late timeing issue.

A Valve adjustment may or may not help. But, it effects compression.

__________________
84 300D, 82 Volvo 244Gl Diesel

The white component of the smoke almost completely vanished with the EGR deactivated, and the car seemed to have a little more pep.

I tried it with no air cleaner, made no difference, not that clogged. It is a little oily in there, but not pooled up or anything. Tomorrow i will try removing the hose that goes from valve cover to air cleaner. Last i checked, i was getting about 1500 - 2000 miles to a quart of oil.

black is beautiful,with a heavy foot.

Why would the white smoke have almost completely disappeared, to be replaced by black smoke by temporarily disabling the EGR valve?

Ever since i removed and plugged the EGR line, the car has been running much better, and the smoke is down to almost acceptable levels.

When i first started it up after disabling the EGR, it put out a huge puff of black smoke, but a few trips to town, and flooring it in 2d on the big hill leading to my house, and it seems to e smokign much less.

Why would the EGR make so much difference, and is there some way to reinstate the EGR and still have it not smoke?

EGRs, when working properly, are used to dilute the fuel air charge in the combustion chamber with an inert gas (ie: exhaust gas) in order to lower the combustion temp and thus lower nitrides of oxygen (a pollutant). With age they often malfunction, bleeding exhaust gas into the fuel air mix at the wrong time &/or in the wrong amount. So, to answer your question regarding differing performance, and also reinstatement, you should begin by making sure the EGR is functioning properly.

On the other hand, diesels quite often get 'loaded up' (and thus smoke) by long periods of idling/light use, and respond very well to sustained heavy continuous loads. I maintain some large stationary diesels used for emergency standby power (multiple 2-3MW units) that have to be 'load banked' periodically to clear up the engine and thus clean up the smoke (move from grey or black to clear). Loading a standby genset involves running it for several hours at 90%+ load. The automotive equivalent would be a sustained uphill run in the mountains. Get the engine temp up into the upper range of normal operating temp. Diesels love long trips.

It is running much better now, and smoking much less. Not sure if the MMO soak, plugging the EGR line, or just several ethnic tune ups, but i took my 240D out the other day, and thought something was wrong with it, as the 300D has so much more power.

I also changed the transmission fluid and filter, and it seemed to go up the hill from my garage quickly w/o even being warmed up. Before it had to warm up about 10 minutes before it would even grudgingly get up the steep hill leading to the real world.

I think i will re attach the EGR vacuum line tomorrow and see what happens.

Question: How do i tell if the EGR is working correctly?

Thanks again for all the great advice.