tappet rattle.

[Pete49]

On my W116 450 SEL I Have tappet rattle on No 5 inlet valve I found it when I, in desperation, removed the rocker from that valve and when I started the motor rattle was gone and when replaced it came back. The gap is set at 4 thou as per specs in the manual and no other rattle in the rest of the valves and all gaps set as per manual. Any help would save a lot of hair.
Pete

[Bartman4800]

Did you check whether the oil flow channels to that rocker are open (not blocked with sludge)?

Did you check the bearing surfaces of rocker and pivot point?


Bart

[Pete49]

Did you check whether the oil flow channels to that rocker are open (not blocked with sludge)?
Did you check the bearing surfaces of rocker and pivot point?
Bart

Hi Bart , yep plenty of oil flowing and no sludge anywhere. Its been suggested to change rocker from the other valve and see if that changes things but not sure if its wise to interchange rockers. If I could access a rocker and ball pin I would replace them but haven't found an Australian site since John shut down MB S[ares. There may be someone in Adelaide with luck though it means a 600 km round trip unless I can find an online supplier.
Pete

[Bartman4800]

Another reason why it's ticking is that the valve is sticking in the guide.
If the rocker is running smooth on the rocker ball, there might be something wrong there.

An Italian tune-up and some oil additives might do the trick there...


Bart

[Pete49]

UPDATE: Found the problem I think. Changed the rocker from good exhaust onto the inlet and the noise went to No 5 exhaust. when I compared the 2 rockers the rocker on No 5 inlet is badly worn compared to the other so now need to find a rocker for the 450 and all should be good. Anybody got a spare they want to sell?
Pete

[Bartman4800]

That's exactly what I meant with bearing surfaces....


Bart

[Pete49]

You are quite right Bartman and I think due to it being the only one and the cam lobe itself in good order I think its a replacement out of a junk pile as all the others (yes, removed them all :whistle: ) are in excellent condition. I've source a new on from the US for $AU 50 including post so onward and upwards. :dance:
Pete

[Chai]

May be prudent to check the camshaft oiler is not blocked and pours oil down to the worn rocker.

[Pete49]

No problem with the oil supply to the rockers. Anyway the new part rocked ( yeh pun) up today and once I put it in and the rattle was gone and just a sweet V8 burble and smooth as silk.
I finally sorted out which model it was thanks to the W116 guys. Its an early 1975 UK ordered model and other than a little paint fade on boot and bonnet the body is in great condition with no rust or other worries. Its silver blue colour with dark blue leather seats and dark blue carpet interior. My next jobs on this unit is the vacuum system and to put in an A/C compressor (Behr or Sandon) hopefully in time for summer and find a rear passenger side carpet as mine is missing.