M104 engine: Timing issue -one for the GURUS - Page 3 - PeachParts Mercedes-Benz Forum

J. M. van Swaay · #31 08-26-2009, 06:52 PM

Jonathan, on the ones you have done, did the hole/pointer tabs look like Latiefs picture or the WIS diagram?

J. M. van Swaay

dhaghighi · #32 08-26-2009, 06:53 PM

Here is a pic of the crankshaft mark, and both cams. Keep in mind that the exhaust cam has naturally moved counter-clockwise approx 1/8" because I have now removed the tensioner. Everything else is exactly as it was before the tensioner was removed.

latief · #33 08-26-2009, 07:03 PM

Have you rotated it successfully while keeping the timing? what version engine is that? it is a bit different than mine as i don't have the water outlet in the head....

latief · #34 08-26-2009, 07:05 PM

also, you could you take a better picture of the pointer looking straight down at it? i am trying to compare relative locations in relation to the rest of the components...

dhaghighi · #35 08-26-2009, 07:39 PM

As previously stated it is a m104 104.980. It is the 1st generation 104 with CIS fuel system, but 24 valve dohc.

Our heads are almost exactly the same except that my displacement is 3.0 liters, and yours is 2.8 liters.

Your problem is that you need to set the timing, install the tensioner, then rotate twice.

I have rotated the engine almost 10 times... and my engine hasn't varied from these marks in the photos.

I have to leave now, so I cannot take another picture at this time, but I can assure you that the 0IT falls right on the pointer to the left of your crankshaft position sensor hole...just as specified in the MB service manual.

So basically, if you start orienting yourself by the ckrankshaft, with the pointer....move on to both cams, and make sure that all the slack is on the passenger side of the car (retarding the cams so that the only slack is in the tensioner area) ...Install the tensioner. Rotate twice to check your marks. If they are not reasonably perfect, you are one tooth off....

If that is the case you need to remove the tensioner and re-adjust.

jhodg5ck · #36 08-27-2009, 11:33 AM

Quite, I just re-read, missed the fact you hadn't installed the tensioner! W/o the tensioner installed nothing is going to read/line up correctly even If your timing is correct:-P

Jonathan

latief · #37 08-27-2009, 12:49 PM

Pictures before rotation

Pictures after rotation - No tensioner installed, but i do hold the tensioning rail in place by hand

Is this OK? (of course i placed the drill bits after i rotated)

jhodg5ck · #38 08-27-2009, 12:52 PM

You Need to install the tensioner.

Jonathan

latief · #39 08-27-2009, 07:22 PM

I talked to Steven Brotherton today...what a great guy!!! will help a complete stranger although he is propably super busy....

he understood the situation right away. he advised me to try move both intake and exhaust cams a tooth further, and see where my marks end-up.

He might log on to see this if he has time....

I will try tomorrow as it has been raining for 7 hours straight ...even the gods are against this project

I will also give it a shot with the tensioner installed to see how much of a difference it might make

latief · #40 08-28-2009, 12:07 PM

I put in the tensioner: same situation...nothing changed ...

I tried advancing a tooth, retarding a tooth, tightening, moving ..etc. i even got the valves touching the pistons on an occasion (i was rotating by hand so hopefully no damage)........anyhow, i put everything according to the manual, and installed the tensioner...screw it, let it be a bit off.....I am done with this, moving on to the next steps......

jhodg5ck · #41 08-28-2009, 12:32 PM

Well, not sure what was done wrong, but be that as it may....good luck!

Jonathan

latief · #42 08-28-2009, 01:27 PM

should i be worried about the valves touching the pistons while i was hand rotating?

jhodg5ck · #43 08-28-2009, 01:39 PM

If you can't turn the engine over by hand turning it over w/ the starter will be Bad.

latief · #44 08-28-2009, 02:02 PM

Quote:

Originally Posted by jhodg5ck

If you can't turn the engine over by hand turning it over w/ the starter will be Bad.

I am not sure i understood that. my question is that while messing with timing, at one instance the valves did touch the pistons for a second. i unbolted the cam to reset everything, and after that everything was fine again. do you think that during that brief encounter, damage might have occurred? this was during rotating by hand with the tensioner off....

thanks for your feedback thus-far...

best,

Latief

jhodg5ck · #45 08-28-2009, 02:03 PM

No, touching a valve while turning over by hand won't hurt anything.

Jonathan