So I figured out this loud tap on cold start. It got faster up to 1500-2000 RPM. Once it warmed up it went away. Just an annoying tap!!!! I personally diagnosed it as a lifter tap. I guess Chrysler AKA Mercedes wants to call this a valve tappet. I decided that my buddy and a few of us guys would do it ourselves. heres the part numbers:

6x upper tappet: 5096540aa (list=12.65 dealer=7.60)
12x lower tappet: 5096539aa (list=12.65 dealer=7.60)
1x left valve cover gasket: 5097105aa (list=24.50 dealer=14.70)
1x right valve cover gasket: 5097104aa (list=23.45 dealer=14.10)

list=276.70 dealer=165.60

Book calls for 2.3hrs of labor and regaurdless of what the dealer ship tells you, you do not have to drain any oil to perform this job. I think I lost about 6 ounces all together. it really only took us 1.25 hrs in a garage on the floor with no lift.

Have fun!!!

 

But did it get rid of the tapping??

 

Good question! I'm curious too...

 

My guess is that it should work.
I have heard many crossfires with very loud lifters.

Before I bought my roadster, I looked at a coupe that sounded like it had no oil in it when it started. I checked the oil, it was fine.

 

Yep, took care of the tapping completely. The only issue I had was getting the valve cover seated perfectly. You gotta make sure its perfect on there and the valve cover bolts are torqued just right or else the valve cover will leak very slightly. If you need the torque specs, let me know. I have that too.

 

please post some pictures of the old Lifters.. where are they wearing?

 

might as well post the torque specs so theyre here for whoever might want them.

 

Just curious what year and how many miles on it? How do you drive it? Thanks

 

I sense the thread poster is BSing here.

 

me too! Doesn't make sense.

 

There are a number of potential problems with hydraulic lifters. Frequently, the valvetrain will rattle loudly on startup due to oil draining from the lifters when the vehicle is parked. This is not considered significant provided the noise disappears within a couple of minutes, typically it usually only lasts a second or two. A rattle that does not go away can indicate a blocked oil feed or that one or more of the lifters has collapsed due to wear and is no longer opening its valve fully. The affected lifter should be replaced in the latter situation.
In certain circumstances, a lifter can "pump up" and create negative valve clearance so that its valve cannot close. Typically this occurs in the most upper rpm range of an engine, and limits the engine's performance. Lifter pump-up is serious, as there may be interference of the valve with the piston or, burnt valves may result. In all cases it is important to follow the manufacturer's recommendations for oil viscosity and quality.

 

I don't believe there are lifters on this engine, only buckets, this is no chevy 350. Please post pictures or otherwise your all full of ****

 

I am not a mechanic but why is there a question about the validity of what the original poster had to say? He posted specific part numbers in his first post. Are these real or not? All one has to do is refer to the mechanics manual on the SRT6 engine to know. If you want to discredit a poster then document what you know instead of just making an accusation.

 

Per Wolfgang's MB Page on the M112 engine:
"Twin rocker shafts in each head hold low-friction, roller-tip aluminum rocker arms to actuate the valves, and housed in the end of each rocker arm is a small hydraulic lifter which ensures quiet, maintenance-free valve operation."