I built a radio-shack code reader, as detailed on the site...i am trying to find out where the exhaust smell i have is coming from (see my post Running with a bad O2 sensor).

anyhow, something not right . when i press the button while the reader is connected to the car, and while the car is running, the led comes on while the button is pressed. it goes off when i release the button. I did not get any single led flashes for no error codes, but i did get some codes nevertheless:

on pin 8, i got 8 flashes......

on pin 14, i got 2, 5, 9, 11 .....

when i looked up the explanations, none of them seem to make sense to me....

is my reader messed up or is this normal? and what is the deal with the codes...

need some help guys, thanks!!!

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1993 300E, 2.8 M104 .....

All of those codes are pointing to an issue with the throttle actuator.......

Would NOT cause a fuel mixture issue, but would(could) cause an erratic idle speed.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks,

I just pulled them again with the switch in the on position (since i pulled them with the engine on by mistake yesterday) = Same codes!!!

I erased the codes, and i am sure some of them will disappear...

so no need for a new oxygen sensor? my exhaust smells terrible and gas mileage is terrible also....

MBDOC, do you have any idea what might be wrong with the throttle actuator? It has the rebuilt harness, and i cleaned it while doing the head-gasket...

thanks,

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1993 300E, 2.8 M104 .....

I just realized something.

E320 16 PIN DTC Charts inc. pin 8, pin 14

When looking at that thread, you can use the built-in emissions bulb if you have it, but if you don't have one, how can you test for that ?

thanks,

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1993 300E, 2.8 M104 .....

I just discovered that my car does not have anything inside PIN 3 for the emissions reading. (It is empty, with no metal contacts)...so how do i go about reading emissions on this car?

the point of all this is to see if my mixture is off causing a bad exhaust smell and possibly damaging the cat and O2 sensor ...

i would appreciate any insight on this

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1993 300E, 2.8 M104 .....

Are you 100% certain your fundamental cam timing is correct? If not, you should set it at TDC, remove the top cover and check your dowel holes. These sound like symptoms of being a tooth off on one cam....

What do you mean by the symptoms of being a tooth off? the existing codes or the exhaust smell?

thanks,

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1993 300E, 2.8 M104 .....

Well, the cams can be mistimed in about 4-5 different ways.
So as far as the smell goes, it depends on what you're smelling... to determine if it's a symptom. Is it a fuel smell? A rotten egg smell? Plastic or rubber smell?

As far as codes go, MB DOC is right about the throttle actuator...but you never know what these cars will do to try and adjust themselves with mixture/timing to correct emissions codes. Is your check engine light on?

How does the car sound? Does it run smooth all the way through the power band? Is it sluggish at all?

Your engine is supposed to have over 200 horsepower, so it should not be slow or hesitant if properly timed.

I am not the only one with this problem

M104 - Camshaft/Crankshaft Position Discrepancy??

I know there was another one i saw, i will look for it

Edit: M104 timing

See post 5, same problem

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1993 300E, 2.8 M104 .....

Latief,

That guy's cams lined-up with each other.
The variation on the harmonic dampener (crankshaft) shows chain stretch. In his case that was 4 degrees.
Because there is such a short distance between the cams, their positions relative to each other should be almost dead-on even with some chain stretch.
10 degrees is just too much to be chain stretch. And based on your pictures, I can see that one cam has rotated much more than the other.

so what do you advice me to do ?


This is how i did this for like 10 times before sealing it off...

1-crank at TDC (chain loose and off the exhaust gear)
2-cams at head surface level using drill bits for reference
3-rotated the cam -free of chain- using they advance/retard mechanism counter clockwise until it stopped.
4-pulled the chain really hard on the right side to get it over the intake cam. chain always seemed to short to go on the next sprocket pin, and too long for the previous pin causing the slack....
5-muscled with the exhaust cam to get it back on correctly. seemed to be some slack between exhaust and intake cams also
5-no way to remedy that slack no matter what i tried, hence the problem!!!
what else could be done? everyone else gets this straight forward process correctly, except their is something preventing me from doing this correctly. and i cannot figure out why no matter what !!! i am fairly analytical handy and intelligent (i think!)


I am going to take the front cover off, and see what could be done. i am expecting something wrong with my chain advance-retard mechanism maybe causing some slack in there? no need for a new chain in your opinion?

thanks.,

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1993 300E, 2.8 M104 .....

Latief,

Thanks for posting that sequence.

First of all, you should be rotating the adjuster clockwise (retard position)before installing the chain. by rotating it counter clockwise, you are advancing the adjuster.

Second....are you saying that with both dowel holes perfectly lined up with the top surface of the head, and the chain fully installed, there is signifant slack between the two cams? ....This should not be....

Keep in mind that the valve springs will force the cams to turn off of their markers. But as long as the tensioning of the chain corrects their positions realtive eachother, you will be fine. You really have to visualize this part in your head. (I had a hard time at first)

Try to rotate the crankshaft approximately 5-10 degrees counter-wise to allow more slack to install the chain. Then snug it back-up after the chain is installed to remove the slack from the driver's side of the engine. Then install newly re-inserted tensioner and rotate to check for accuracy.

It will be hard to get the 0IT mark on the harmonic balancer to line up while the cams are perfectly aligned, but this will be an indicator of the stretch of the chain. The important part is that the cams line-up almost perfectly with each other. When they are aligned, look down to check the harmonic balancer. If you are less than 3-8 degrees off the 0IT mark, you are probably properly timed. If your variation is more, you are probably one tooth off.

To start off, just remove the upper timing cover and rotate the engine by hand/starter until the exhaust cam dowel hole is perfectly lined-up . Then check the intake cam to make sure it is also lined-up. If these are not currently lined-up with each other, then you will know you need to re-time.

that was a typo on my behalf, i rotated the cam timer counter clock-wise, sorry.....

there was some slack between the two cams before i rotate and tension. once i rotate and tension, then the slack is gone....

I guess i will have to take this apart and try your techinqe ...are you sure it is ok to go counter clock wise on the crank? man that is alot of work to get that front cover back on.....

no need for a new chain? i would hate to change that and find that the situation remains the same....

what baffles me with all this is that the tech who did the head gasket before (and i am assuming it was done by a tech) could miss something like this....why am i the only person who is having a problem with this?

Edit: I will take the cover off soon. I will update this...

thanks,

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1993 300E, 2.8 M104 .....

Less than 5deg stretch is normal & OK.

More than that & you would want to replace the chain.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

thank you,

by looking at my second timing mark picture, can you tell me how many. in that picture, both dowels are aligned perfectly with the surface, and the OIT mark is slightly forward of the pointer as appears in the picture (the picture before the last). can you tell me how many degrees forward that would be roughly? i don't really know....

Thank you for the answer ....

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1993 300E, 2.8 M104 .....