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.

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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 sure about the smell, but it smells like a slightly rotten smell (old car smell)...

if i had timing issues, wouldn't they trigger a code ....???.

I am worried because if you remember this thread, you might be right on the money

M104 engine: Timing issue -one for the GURUS

this had no solution, and i buttoned the car back up the way i found it. i talked to Steve Brotherton and he suggested that the head might have been shaved more than once (or shaved heavily once) causing the extra chain length.....please don't tell me that this came back to haunt me

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1993 300E, 2.8 M104 .....

What was the status of the dowel holes when you closed the covers?
Was it the same as your pictures in the thread?

If so, I would definitely say you are one tooth off...those bits were nowhere near level. And they should atlleast be level with eachother, or be really close.

If you rotated the crankshaft a bit, did the cam dowel holes line up better as compared to eachother? if so, that would indicate stretch. And you can measure it by the variation on the harmonic damper.

Did you check the stretch?

The status was a tad better than the pictures since everything was in place, but still off....there was nothing i could do about it at the time, tried to advanced both a tooth, but it ended up with valves touching cylinders while hand rotating....

people assured me (or the consensus is) that 104 chains rarely stretch...i guess i have a unique case? I would think i was about 10 degrees off....

so a new chain will fix this ?

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1993 300E, 2.8 M104 .....

Just read through the thread again and realized your problem.

"I decided not to test-it and worry too much about. went by what the manual said, and what the people were recomending. put everything back together, and started it ....i did not try to check it after that and it has been running ok since then...i would imagine that the for the dowels to align properly, the TDC mark will be in the center of the circle on the TDC locater and not at the pointer where is should be......(you remember this whole debate, i am sure)".

You should never take this approach with auto mechanics....especially Mercedes. Everything should always go together very precisely. And the methods of checking timing/stretch have been developed for a reason.

Even a head that had been resurfaced 3-4 times wouldnt show that much variation in cam timing (relative to each other).

I recommend a tear-down and re-time..

the problem is that if i re-time, i am stuck with same problem again. believe me i tried everything i could think of at the time, and all the recommendations. nothing worked. something is out of spec and needs to be repaired. do you think it is the chain? what else could be wrong?

thanks,

Edit: by the way, this is how the car was prior to the headgasket. that is how it was timed!

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1993 300E, 2.8 M104 .....

I would wager that all your timing/valve parts are still in working order if your engine is running.

10 degrees sounds like exactly one tooth on the cams. As I recall, the cams have 36 or so teeth (10 degrees each).

Your computer is trying desperately to adjust timing and compensate. That's why you are getting codes and smells.

Also, you may have Throttle actuator issues after your timing is fixed. (I am not extremely familiar with the HFM models).

If I was in Florida, I would come time it for you for a small fee, but I cannot do anything but advise you based on your photos from here in CA...

Latief, based on your photos, the car is mis-timed.
If it was like that before, then the previous repairman mis-timed it as well.

I think we went over this in your gurus thread, but your slack must be in the wrong place. That is the only way you would be all lined up before rotation, yet lose your timing after the chain finds itself.

If your valves touch your pistons while rotating, do not keep rotating. You will not damage your valves if you stop when you feel resistance. But then again, if your valves are touching, you have gone too far. Maybe you were adjusting in the wrong direction? Don't be scared to turn the engine counter-clockwise for 10-20 degrees if you're sure that you arent fighting valver resistance.

I don't think you are being patient enough. You need to really conceptualize the chain and where it should be so that once you rotate to test, the tension is taken up in the correct areas.

If you take the top timing cover off, you will be able to check chain strech, as that is the only thing that could cause this. (And extremely uncommon)