Please help! 240D smoking and high fuel consumption
 

Hello everyone, I need your expert advice please. I'm from South Africa and recently bought a 1981 240D manual with 139 000 miles on the clock. When I bought the car it used to smoke a little blue when idling for a few minutes, hot or cold doesnt matter. It's also very heavy on diesel, not even getting close to 20mpg and thats with mixed driving, 60% highway 40% town.

It starts first time everytime and runs smooth, it is a little noisy on cold starts, it makes a clacking sound which appears to be coming from the valve train area, rockers maybe? I have adjusted the valves on the weekend, which were way out of spec and took it for a drive afterwards, car felt the same and was still smoking at idle rpms.

So, after that I drove the car warm to do an oil change and when I got home my father suggested we add 1 liter of diesel to the oil with the car idling for about 30 seconds to get all the old oil out which were very thick. Not too sure when the previous owner changed it but it wasnt recently thats for sure.

We drained the oil and filled it with 15W40 diesel oil and when we started the car the whole neighbourhood had a cloud of white/blue smoke over its head. My dad said that it will clear up but after driving the car for 80 miles it still smokes and I mean clouds of white/blue smoke, even when driving now, which never happend. I wish we never added the diesel, I think that have destroyed it or could it be something else?

I have checked the coolant and all seems well, definately not the head gasket.. I have read about the injection pump's timing, egr systems and vacuum pumps going bad on these cars but am slightly confused, the timing chain was never removed on this car so how can it just go out? Also, mine doesnt appear to have the egr system.

What I did noticed from the day I bought it is that there is oil in my vacuum pump line which only goes to the brake booster, mine doesnt go into the intake manifold like some others and it seems that the oil is only near the brake booster area and doesnt appear to be coming from the vacuum pump? What can this be,a failed brake booster perhaps? Brakes are still fine though..

I have attached a photo of the engine bay to show vacuum pipe.
If anyone can give me some advice it will be much appreciated as I have very little knowledge about these diesels. Starting to regret selling my 190E :(

Thank you for taking the time to read this post.

Wow...adding a liter of diesel to the crankcase oil was an extremely bad idea...aside from overfilling it, that could have damaged all sorts of parts....bearings....rings....

Have you done a compression test?

your injectors could be worn,and pissing away diesel,you need to check as they can burn a hole thru a piston.very low miles suspect they could be sticking.would not worry about diesel used in oil,I had to clean a gas motor,because screen was clogged.I fill engine up after drain oil with a gallon diesel.Ran it with the starter over 5 turns,then drain,and filled with new oil.Its a crude way to clean a engine,but it worked.

First check your odometer to be sure its accurate. SEcond verify that you have no brakes dragging. I'd look at the motor last if it runs well.

Sounds like they may have had a viscosity increaser added in the oil perhaps. This to reduce oil burning etc. That may be why the engine oil you drained out seemed so thick. At 139 k miles the interior should still be very good. Many of these in north america have very untrue odometer readings.

The oil in the vacuum lines may be from the engine shutoff device. I can not think of any other sources at this time. This I suspect still should not create your current difficulties

I know a quit group.

If the 139 000 miles on the Engine is correct someone must have neglected or abused it to have the issues you are having.

You likely have several problems.
Blue Smoke is associated with burning Oil. In your case that can be Piston/Rings/Cylinder issues or your Valve Stems Seals and Stems and Guides could be worn and allowing Oil to drip past them.

White Smoke is associated with a Coolant leak into the Combustion Chamber or very late Fuel Injection Pump Timing.
With the timing issue the white not exactly smoke but is unburned atomized Fuel floating in the Air.

If it was purely white you would smell the Diesel Fuel Smell in the smoke but that might be hard to do with the Blue Oil type Smoke smell.

To a lesser extent the same thing can be caused by the Injectors but I have not read of anyone having as severe of symptoms caused by the Injectors at the mileage you list. When I got My Car it had 198K miles on it and the Injectors were the originals and I did not have that white smoke but My Compression is good.


Checking the Compression sounds like a good idea.

If you have managed to drive 100 miles of so People say to recheck the Valve adjustment; when the adjustment has been neglected curd builds up on the Valve Face and the Valve Seat. If you adjust the Valves and drive it a while it beats the curd off but at the same time changes the Valve Clearances, meaning some of them may tighten up again.

While you have the Valve Cover off turn the Engine by hand in the direction of normal rotation and line up the timing mark on the back of the Camshaft Gear with the timing Mark on the Camshaft Bearing Tower. You must do this very exactly.
When you do that look down at the Pointer on the Crankshaft Damper and see what degrees the Pointer points to..
When the Engine left the Factor it was lined up at OT (that is top dead center). As the Engine is used and the Timing Chain and Gears wear the Camshaft Timing becomes late.
At you stated Mileage one would expect maybe 1-2 degrees of late timing.
If you go over 4 degrees late there is different sized offset Woodruff Keys to return it back to the original Timing.
I mention this as you said something about thick Oil. The Timing Chain seems to be the first thing to suffer when the Oil is not changed on a regular basis. Meaning it stretches more and I assume the Timing Gears also wear more.
Also the stuff above is just a rough check of the Camshaft Timing. There is a more precise check called the 2mm Method.


Was this a Car that some Alternative Fuel was used in? By Alternative Fuel I mean anything but Diesel Fuel or Biodiesel Fuel.

The Pic shows on the left of the Pic the Camshaft Gear and Bearing Tower lined up. The right side of the Pic shows My Crankshaft Damper and Pointer. I Wrote OT for Top Dead Center and showed 5 degrees after Top Dead Center/OT.
If you look close the Pointer is between OT/Top Dead Center and 2-1/2 degrees so I have less than 2-1/2 degrees of late Camshaft Timing. This is not enough to correct with an offset Woodruff Key because the first one corrects 4 degrees of late Camshaft Timing.

You did not mention if you had a lot of Blow-by when the Engine is idling and the Oil Fill Cap is off?

Look at this pic. On your 240D the circled item in the pic on the Fuel Injection Pump should have no hose connected to it and the hole it that nipple/vent should not be plugged.

How to do various stuff; DIY Repair Links
http://www.peachparts.com/shopforum/diy-links-parts-category/
http://www.peachparts.com/Wikka/DoItYourSelf

How full is your crankcase? What does the dipstick read? the oil in the vacuum line is very odd. Can't figure that out.
Post a video of the blowby--with the engine running, take the oil fill cap off and film it.
Take a video of the smoke.
Is it possible you have an engine with the diaphragm in the IP and a butterfly valve in the intake.
It's very odd to see everything backwards in the engine compartment.

In the Picture His Fuel Injection Pump has a Mechanical Governor.

Thank you so much to everyone, especially to you Diesel911, I really appreciate it a lot. My internet connection was off yesterday afternoon so I couldnt reply. I have taken the car to a diesel mechanic and he said that it was a terrible idea to throw the diesel into the engine, he told me that it's a very dangerous practice on older diesels because it loosens up too much of the gunk inside which makes the engine go bad?

Anyway, he told me to find a road where there are a lot of hills and drive the car flat out and then after immediately drain the oil and add new oil and a new oil filter again.. I will definately first look at the valve clearances again and check the timing before driving it that hard. I've noticed yesterday that the exhaust was wet in the inside, looks like the old oil and diesel mixture got into the chambers and was blown out through the exhaust.

Just one question to Diesel 911, when I adjust the valves, should the cam lobe face straight up at a 180 degrees or should it be at the 1 o'clock position?

I have checked the circled item and everything seems to be normal, no hose connected and doesnt appear to be blocked. I have started the car and opened up the oil filler cap, it sure danced around a lot but wasnt blown off but I could feel the air being blown out from underneath it. Is this normal?

The oil fill cap not blowing off when loose is far better than it blowing off. Although if the car is still blowing a lot of blue smoke with no noticeable fuel smell. It pretty well will be a wear or damage issue in the engine I suspect. Could be a broken valve guide for example. Or if really overheated some time the temper in the rings may have been reduced. To do this though you would have to get the engine really hot with all the coolant blown out.

Check to make sure the engine vent to the air cleaner is not supplying excess oil for the engine to burn. Pretty normal for these older engines to have some blowby. Usually when excessive the cap will not remain on a warmed up engine. Although not too common perhaps the oil feeder passage to the head has breeched the gasket to the closest engine cylinder.


Anyways it sounds like some serious investigation is in order. Perhaps doing a compression check and checking the appearance of the injectors by comparison with each other to see if one is largely different. If you find any evidence at all that vegatable oil was used as a fuel mention it. The rings could be partially seized and the thick oil was poleramization from the residue getting down into the oil from the vegetable base fuel..

Thanks Barry. The car was never run on veggie oil, it's not very popular in south africa yet. It may have been run on low quality diesel though. We drove it a bit hard yesterday and the blue smoke did seem to get less as it warmed up but it still blows out a huge cloud of white smoke which smells like unburned diesel when I start it everytime. Hot or cold doesnt matter.

It's first the white smoke that appears on startup and after about 10 seconds the white smoke disappears and then it turns to blue smoke but a lot less. I wonder if it may be fuel related rather? Anyway, I will do a compression test asap, hope it's not going to be an engine rebuild for me.