smoother running engine

[nick350]

I know that my car is old and its done about 150K miles. It runs well and starts pretty uch first time too. I have over the last few days driven about 800 miles both in towns, on mototrways and through country lanes. The car is serviced on a regular basis and so I have everything in order, however......................what can I do to make the engine run a little smoother and quieter and just to be a little more refined. At 60mph it is so sweet but just sounds rougher at lower speeds. I am having the valve guides replaced next week. Any ideas?

Nick350
r107 SL red
w113 SL white

[JimVillers]

Nick .... Install a Pentronix electronic ignition.

Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor, MGB 5-Speed

[Cees Klumper]

You may want to check the sound insulation between the engine and passenger compartments. On my car there was a small hole, letting a lot of noise through.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[hands_aus]

It might sound rougher but does it run rougher?

One of the problems with Pagoda owners is that we 'listen' to our cars where in fact we should turn up the radio/stereo just a bit and listen to that.

Is the idle speed at spec? Sometimes a low idle can cause an automatic car to seem to run rough.

Maybe with all the running around you have burnt all the carbon build up out of the car. It might be worthwhile checking the air/fuel mixture

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[rob walker]

Nick, I found that there was wear on the distributor which caused rough running at lower speeds, had this changed and added electronic ignition (not favoured by some on this board) and it made a huge difference.
Silchester carried out this work for me, not too expensive.

Rob Walker
1968 280SL papyrus white/green leather
Spain and Turkey

[rob walker]

Nick, did you get her running better?

Rob Walker
1968 280SL papyrus white/green leather
Spain and Turkey

[nick350]

I already have electronic ignition and new coil. I am having the head rebuilt then having a rolling road tune up done. I will report back.



Nick350
r107 SL red
w113 SL white

[Shvegel]

As someone who has done a fair amount of tuning on classic and sports cars here is what I do.

Adjust valves

check compression

replace spark plugs(NGK or Bosch. No platinum or Champion resistor plugs)

Replace points and set timing (I have a pertronic on my car and I love it).

Set up carbs or injection.

If that doesn't work start looking for problems. Bad cams, plug wires, distributors etc.