15 means something is way off. Especially with a stick... what are your RPMs at 70 mph? The least I have ever gotten is close to 19 mpg and that is really really beating on it (aka sliding around town and chirping tires). Check your wheels for brake caliper drag, do a valve adjustment. Make sure your engine gets up to 80 degrees celsius and does so in a reasonable amount of time, like 15,20 minutes. Could be a leak too, any diesel puddles under the car? I got 13 mpg once when my fuel line sprung a leak. It actually started and drove fine for the two days I waited for the part at the dealer. Do you get a massive smoke screen or waht? It might be your alda is over adjusted too. It's right by the injection pump. If it's a virgin one, it'll have a black cap on it. If it's been touched, it'll be a flathead screw with a nut around it.

__________________
1985 CA 300D Turbo , 213K mi

G'mornin',

Am glad that you found that leak......

SB

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Thanks Shorebilly.
I Just took my 60 mile drive in to work. I had removed the feed and return line under the floorboards back when I was welding in new floorboards prior to my paint job and I remember I was in a rush.
I could tell the mileage is okay because the fuel gauge didnt budge an iota and recently I was getting some movement. Also I think one of my rubber lines was leaking. I also had bent/misadjusted linkage problems
Boy the engine sure is quiet!
Finally everything is back to normal and with the new chain and valve adjustment and ip retiming I get a big smile listening to her at the stop light. When I did the valves they were really out of whack especially the exhaust valves, I couldnt get a .030 or .035 feeler gauge under there. The ip was way off too.

You've got the combination of excessive fuel and no torque. By your own admittance, you can't drive the vehicle below 2000 rpm. So, what would cause an engine with good compression (I'm assuming this for the present, without any data) to use much more fuel and have no off the line performance?

The answer is usually the basics:

1) IP timing way out of spec.
2) Camshaft timing way out of spec.
3) Valve lash way out of spec.


The excessive black smoke is typical for a leaking or dripping injector. An IP that's dumping way too much fuel is also possible, but would be quite uncommon.

You've got several issues with that vehicle that will take a bit of time to sort out..........only then will the fuel economy climb.

While you are in the area Brain can you state the Bowden Cable rule?

The white threaded plastic part of the Black Bowden cable sheath turns in a Black plastic nut on the Throttle Linkage on top of the Valve Cover. Part of this white threaded part is on the side of the injection pump and the other part is on the passenger side.
To make my car shift from 1 to 2 to 3 faster (hit the shifts earlier) , do I lengthen the white threaded plastic part on the side facing the injection pump or shorten it?

This always gets confusing because people usually mention the adjustment in terms of cable slack which just confuses me. I was going to PM you to protect my guru status but I guess I am more gorilla then guru as I get older.

The white threaded part should have a set of wrench flats on the end........on the passenger side. If you want the shifts to be earlier, turn the white threaded piece inward (clockwise) to put more slack in the cable.

If you want the shifts delayed, turn the white threaded piece outward (counterclockwise) to put more tension in the cable.

Thanks Ara!

RPMs at 70 MPH (in fourth): 2,840 (3,000 @ 74 MPH) (4,050 @ 100 MPH)

At best, the odometer is counting only 8 out of every 10 miles traveled! With that in mind the fuel mileage is closer to 18.5 MPG, which is still awful.

The temperature warms up to about 85-90 C. pretty quickly, and seemingly never wavers.

If I am looking at the right black cap over the IP, then the alda is virgin. There are no evident fuel leaks, or fuel dampness. It does not look like the injectors have been inspected or removed in some years.

It does look like the throttle linkages have been tampered with, altered, and edited/eliminated in places. The cruise control(?? I am not sure what this part is, but it is front and top between the power steering pump and the timing chain) is apparently unlinked and removed to allow for a conversion to a Rostra aftermarket universal cruise control conversion, which is incomplete and inoperable, so far. I am on a learning curve here. I would not mind learning how to restore and reconstruct the original system, but it was alleged by the dealer that it was incompatible with the manual transmission conversion.


Exhaust smoke is gray(?) but there are heavy soot deposits above the tailpipe on the bumper. I do see lingering small clouds behind me when accelerating. As I said, traffic behind me always drop back a few car lengths, due to the offensive output.

Thanks again,

Garth

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2001 E320 4MATIC WAGON desert silver/tan, 169K
1986 300SDL black on black, 240K

1984 300 SDS (stick-shift) 209K.....now reborn as a 1983 300SD (stick-shift facsimile of the former 84) 274K

1982 240D (sold!) 264K

Thank you Brian! I'll be a sponge and listen to you and Ara T. as I try to sort this out.

edit: I'll want to do a valve adjustment soon. I need to find some valve adjustment wrenches. I guess I can check the chain stretch after the valve cover is removed. I changed the chain on my previous 240 D with four extra helping hands, last spring (that's a very stress inducing procedure!). Darn, today is warm enough but foul weather is hours away.

Garth

__________________


2001 E320 4MATIC WAGON desert silver/tan, 169K
1986 300SDL black on black, 240K

1984 300 SDS (stick-shift) 209K.....now reborn as a 1983 300SD (stick-shift facsimile of the former 84) 274K

1982 240D (sold!) 264K

Do you know the history of this car? Maybe it was a drug dealers car, check the fenders for a couple hundred pounds of cocaine? I'm assuming you dont have an anchor in the trunk of your car. Start with the easy stuff, in this case it would be checking for leaks and doing a valve adjustment. It seems your cooling system warms up quickly enough. I picked up a couple MPG after I changed my radiator cap! Check yours for cracks and tears. Though it seems good enough if it gets up and past 80 degrees. If your calipers are dragging you can improve fuel efficiency there too. Another obvious one here is tire pressures, you can easily lose 1 or 2 mpg if they're not inflated enough.

Thats where I'd start.

__________________
1985 CA 300D Turbo , 213K mi

For the gentleman blowing smoke. Have you examined the air filter? Perhaps the previous owners have been a little negligent. If that filter is in a terrible condition you have the bulk of your problem. Not likely but a fair possibility if never checked. A lot of owners do not realise lots of air is required to get a good fuel burn. I am probably wrong but have a look. For a short test leave it out for an hour if it is pretty dirty but you are not sure if it's the filter. Simple easy test. The next thing if it is not that might be to check the engine timing. You do seem to have some symptoms of that kind of problem as well. Far more than injector problems in fact. Also some indications of really tight valves perhaps. I would proceed in those steps in the same sequence as noted perhaps. Might just swap the check the valve clearances with pump timing though. You will feel somewhat more comforatable with working on the engine in the future by doing the general checks yourself now. Always nice when it sometimes works out to be pretty easy. .Best of luck.... Do also take a few minutes to inspect your turbo as well. It might be contributing somewhat to your problems by being semi seized and leaking oil. I am not really sure of my last remark but I would have a quick look. If you can hear it spinning at idle by listening carefully and there is no evidence of oil where it should not be of course pass it by. Use a large screwdriver perhaps as an aid to listening. . Or you could remove the U tube and check the impellors freedom when it is cool plus also for excessive play. The archives will have excelent proceedural methods. By doing the above steps you should get at least an indication if not a cure somewhere. Best of all without spending any money if you are lucky.

Thanks Ara T., and Barry!

Ara, I will do a valve check on the first opportunity. I can't afford that special wrench set yet (I always got by on the 240D, adjusting those valves without it).

Barry, Great tips! The air filter looks good. It's a quality Mann filter with a lot of breathability left. Funny, now that you mention it, I don't seem to hear the turbo anymore (like I thought I did a couple of weeks ago at purchase). I am not sure it does anything noticable at idle, but revving the engine by the throttle linkages demonstrates there is at least some minimal turbo action lingering for a second, after the bottom of the rev. No soprano whirr sound though.

I don't yet know what is normal. I'll try loosening the U hose tomorrow in the daylight and see how free the impeller is. To be continued....

Garth

__________________


2001 E320 4MATIC WAGON desert silver/tan, 169K
1986 300SDL black on black, 240K

1984 300 SDS (stick-shift) 209K.....now reborn as a 1983 300SD (stick-shift facsimile of the former 84) 274K

1982 240D (sold!) 264K

I've been told by many professional Mercedes mechanics that those Turbo's rarely go bad. I am also told that if they did, you would know it instantly because they account for a significant portion of your vehicle's horsepower. I'm not sure this is true, because I'm missing my Turbo "whistle" at high speed also, and I can't get my 85 300D to 90 mph when I floor it. I'm not sure its that easy to test this as it is in a gasoline car where you can stick a vacuum hose on the intake manifold and check boost pressure.
In my case however, I think its a Linkage problem or other setup problem. Sometimes the white line running from the back of the intake manifold through a Solenoid into the Alda on the Ip gets clogged. Please check that first.

To follow up, I did a valve adjustment today. Wow, what a difference!

Most valves had too tight a clearance, while a three were found with too great a clearance. I adjusted each to .10mm for the intake, and .30mm for the exhaust. Here's the breakdown of the clearances before adjustment:

cylinder 1:
exhaust-.23mm
intake---.0 too tight to measure

cylinder 2:
intake---.08mm
exhaust-.38mm

cylinder 3:
exhaust-.19mm
intake---.15mm

cylinder 4:
intake---.0 too tight to measure
exhaust-.33mm

cylinder 5:
exhaust-.28mm
intake---.0 too tight to measure

So, the readings were all over the place. I wonder if someone did a botchy adjustment in the past, or if these valves have been neglected for some time? Is this kind of variance normal to find?

The engine idles smoother, makes considerably much less smoke, has more power, better braking action upon de-acceleration, and sounds meaner. I hope the fuel economy improves a little.

I checked the timing chain stretch, and it looks to be between 5 and 7 degrees off from perfection. Is this within acceptable limits? How stretched should a chain be allowed to become, before changing it?

By the way, I just was not listening well enough before. OF COURSE the turbo works fine!

Carrameow, sorry for piggy-backing on your thread. I'd love to see you working on one of your cars sometime. I can't be too far away from you. Great website! You do great work! Where does one get a good can of Midnight Blue paint?

Thanks all,

Garth

__________________


2001 E320 4MATIC WAGON desert silver/tan, 169K
1986 300SDL black on black, 240K

1984 300 SDS (stick-shift) 209K.....now reborn as a 1983 300SD (stick-shift facsimile of the former 84) 274K

1982 240D (sold!) 264K

Nothing really suprising here. Car has just not recieved any maintanance probably for a dogs age. I would do the pump timing soon as well. Have a good look at your chain guides to make sure they are in pretty good shape and perhaps buy a correction keyway for the camshaft. If car is really still pretty good you might decide to roll a new chain in. Use the dial gauge to get a real accurate picture of how much stretch is really in the chain before deciding what to so. Perhaps thats the method you have already used to get your 6-7 percent. Car will benifit in a lot of ways if you do the above items. Not prohibitivly expensive either. At least it has been pretty straigtforward as well so far. If car was neglected perhaps I would check rear end fluid level for example and have a real good look around. Belts, hoses and any other normal wear item for example.

I had the same results also, incomprehensible valve readings and a stretched chain. After adjusting the valves and replacing the chain--heck, its 90 bucks, my engine is so quiet and clean its not funny. Sounds like it came from the factory........