Huge lifter knock CIS M104
 

Aside from my coupe being a full fledged 5 speed (yes the swap is done), I've got a problem.

During the swap, I've done some maintenance bits to the car and gave it an oil change. Mind you, the car had synthetic 5W-40 for the past 5k miles. I did an oil change with 15W-40 Mobil Super 1300 diesel oil. I probably screwed up right there.

Here's the story;

Earlier today, I was putting the finishing touches on my 5 speed swap and went out for little drive to test things out. Driving along everything is as smooth as silk. Being overly anal about my car mechanically, I didn't rev past 2k rpm and when everything checked out OK, I backed into the garage.

NOW,

While I was backing into the garage, I let the car idle for about a minute or so. By this time the car was at operating temps so I thought, I'll give it the beans for a second to clear the spiders out of the exhaust (there actually were spiders in the exhaust!). I rev it up to 5k RPM and when everything settled back down hell broke loose. Oil pressure gauge died and pegged at "0". Car's running as it always and I let it go for another second and I shut it down.

After a minute or so, I start the car with the oil cap off and it's spraying oil at me continuously, so I'm going to assume it's getting oil and the oil pump is okay. So I let it run a little and I start getting a knock at the very back of the engine. I shut it down and think to myself, why couldn't the drive shaft just shoot out of the floorboards and nail me in the eyeball. So I start it again to diagnose and the knocking gets louder and it stays at this sound level consistently now. I increase RPM sightly and knocking is continuous and increases with idle speed, so I think lifter, but it doesn't explain my oil gauge.

To add to my frustration, I did my oil change while the car was on jacks and SOMEHOW, I managed to overfill the &$#*#( oil! How stupid of me! I don't know how I managed to do it. I managed to overfill by a decent amount as well. Stupid for me not to check oil level with the car on all fours again. Excess oil is drained - oil level is now good.

So, I can start and run the car and it runs well and starts fine, but I have a huge knock at the rear of the engine AND my oil pressure gauge is pegged at "0". Other than that the car runs well. No shaking and all is well. Did I fudge up something here with my dino oil to synthetic back to dino oil changes? What the hell happened here?

I'm going to assume that age, mileage, and possible overfill protection on the oil pressure switch caused it to fail so I'm going to replace the pressure switch with a good one I have (then if it fixes the gauge I'll get a new one).

SO.. questions.....

- If I replace the pressure switch with a good one and it still doesn't register oil pressure, what to do?
- What to do with my knocking problem towards the rear of the engine?


NOTES:

Knocking noises are coming from the TOP of the engine. No bottom end knocking.


I'd appreciate any and all help here. If I get this fixed I'll reward with my 5 speed swap write up. http://www.benzworld.org/forums/imag...s/thumbsup.gif

Thanks all!
Allen
(Dunce)

Ok...

I swear I replied earlier, but something is not right with the site? !?

Change the oil back to the synthetic stuff and see what happens....

Thread got deleted because of some naughty language, sorry about that.

I'll try some synthetic again. Fingers crossed.

There is a plug in the rear of the camshaft that can work loose over time. When it does it will give symptoms like you describe. You will have to pull the valve cover to confirm.

Do I just put this plug back in place? I'll need some help on that one. What does this plug do?

I'll be checking otherwise tomorrow when I pick up a friends pressure tester.

The camshaft is hollow and carries oil pressure. When the plug comes loose the valve train doesn't get enough oil at the rear of the head and you get a clattering. If it were mine I'd probably clean everything real good and press it back in with some red loctite. I think there is an updated part from M/B but I don't recall any specifics. If you're willing to pull the camshaft out there's lots of creative ways to repair it.