please excuse my English if not proper. Thanks.

Before my last service, my 2001 e320 ran as smooth as silk. Well she's hit
100k on the clock so I treated to her to some new plugs and an oil change. I used the Bosch plugs that only MB parts counter sells and I reluctantly bought 05-40 reduced emmision Mobil 1 oil from MB as well. The car has only used 0-40 Mobil One since the first change. After my indie completed the work I drove it home. I immediately noticed more power good, I also noticed a little shake at idle, hotter temp and a new ticking noise coming from the right valve cover. Would the different oil cause a valve tick...? It's pretty loud and has me a bit worried. My indie sugggested new wires....any suggestions?

Is it a pronounced ticking sound as like a valve would make? Or is it a snapping/popping sound like a plug wire is not installed properly? If a plug wire is not fully snapped on the plug it could make that kind of sound and also produce a rough idle. Before you go and spend any more money on wires and this mechanic I might take it to another shop for a listen..........

Good luck.

Jeff

Don't use that oil! MB no longer suggests using the 5w40 ESP Formula M Mobil formula in gas cars in the United States because the high ethanol content in our crappy gasoline does not agree with the new ESP oil. MB now specs 229.5 oil for all non-AMG gas engines, which includes good old Mobil 1 0w40.

It is for sure a valve ticking noise. I am going to bought some 0-40 Mobile One oil tomarrow and take it to my indie mechanic repair house and have him change the oil to tell if it's the problem. Thanks, and I will tell you the results after I have done. Thanks.

Should I be angry at the Mercedes house that sold me the Oil! I guess I should have made sure he sell me the 0-40 oil like I ask for him to sell me. I hope it fixes the ticking problem. I will come to this web site and tell you what has happened after tomarrow when I have 0-40 put in my 320.

or 5-w40 should not have made a cam follower tap,even if 0w40 is the preferred oil.5 w is only at start up and it is not that much of a change in start up viscosity.At temp, 40w is 40w and you won't have a noise.
Why are you having a shop change either plugs or oil?
Easy diy's and then you can know what you installed and that you did it correctly.
NGK 7090 plugs are 3 bucks each.How much did the dealer charge you for plugs that do the same job?

are you sure the ticking is not the purge valve,pumping along?

SAY what!!!! 0w40 to 5w40 will cause the ticking . I think not. I agree with citrus check insertion of plug wires.

I agree with Ohlord; my purge valve and the tensioner threw a curve ball at me thinking it was the engine tapping. Don't always assume it was something that you fixed previously will cause a another problem, but quite possibly. When I fixed the tensioner the noise went away, also my harmonic balancer was making a tapping noise. MB had a recall on that any they fixed it for free. Now, my car is quiet and rides nice.

if plugs were changed make sure the wires are seated properly as this sounds with ruff idle like a loose plug wire and not oil. Viscosity would not make that kind of change in driving eel. It has to be the plug wire. You might be hearing the plug wire arc to the surrounding metal and not firing correctly to the plug itself.

You are exactly correct. It was the number 5 cylinder plug wires. I bought new ones from MB at 80 dollars for the pair. I am really glad they sell them in pieces!! A whole set..wow $$$

Just a note. They are the same length in the middle cylinder plug wires. The MB shop man sold me a long and short one, longer costing more money..mad...I also put 0-40 back in her. Peace of mind for me. My indie did the plug wire exchange work for no money because I letting him keep my new but drained 05-40 oil.

Awesomel. Did you ever get a 'Check Engline Light' during this ordeal?

No. In afterthought, I should have know the problem making this ordeal due to the car shaking while it idle. It never shakes before. Thanks to all for advice!!. This is a great place on the internet for knowledge on Mercedes cars! Happy motoring.

glad you got the problem solved.