Valve Adjustment = Power Loss??
 

I just adjusted the valves on my 77' 240D using the special "Hazet" wrenches, and all went smoothly...my intake valves were all too tight, but my exhaust valves were all still within spec...not sure if that's normal or not.

Anyway, I adjusted all of the intake valves to .10mm as indicated on the sticker on the radiator support. Starts up and idles more smoothly now, but I swear it's lost about 1/3 of it's power! (and we all know how slow these cars are to begin with) It could barely muster 25MPH up a moderate incline on a side street. :( The thing just doesn't MOVE. The power was just barely adequate before...but now it feels almost undriveable.

Could adjusting the valves have caused this?? I can't personally see how this could be a result of the valve adjustment, but maybe I'm missing something.

Primary fuel filter has some dark specs in it, but nothing shocking, and it appears to be flowing...It idles fine, and doesn't really smoke at all under acceleration.

I clocked the 0-60MPH time at about 36-40 seconds depending on the grade.

Make sure that your linkage is bottoming out on the IP when your foot is on the floor.

Sure you didn't mix up the intake and exhaust valves?

I'll check the linkage.

I am sure I didn't mix them up...I not only had the diesel giant tutorial right next to me, but I looked at the manifold on the passenger side each time to make sure.

You didn't mention the exhaust valve settings. In any case, I would recheck the adjustment on all valves - cold. Valve adjustment has a huge influence on timing.

How is your air cleaner? Lack of smoke tends to suggest that its not air starved, but it is still worth a look. The small adjustment to the valves is unlikely the cause of lack of power.

Same thing happened on my 240D after valve adjustment, loss of pep. I readjusted them to the tight side of spec clearance and the power came back.

Tight Valves will open and close in advance of what they should.
Perhaps your Camshaft Timing is retarded due to Timing Chaing stetch/Timing Gear wear and the tight Vlalves being advenced actually helped the Engine Run Better.

Line up the Camshaft Drive Gear Timing Marks witn the Timing Marks on the Camshaft Bearing Tower and the Pistion coming up on the compression strok and see what degrees the Pointer down at the Cranck Shaft Damper points to.
the attached pic is a split pic. Left is the timing marks and righ is my Crank Damper and Pointer showing what I believe is 2 1/2 degrees of lat Camshaft Timing.

Well, I sure feel dumb. I placed a large brick on the accelerator pedal, and the linkage was only opening about 1/2 way! :eek: It looks like it was out of adjustment to begin with, and somehow got bent during the valve adjustment.

It's now adjusted perfectly, and oh man...this is the most power the car has ever had!

Rechecked the valves and they are all perfect still. However, there was something I saw inside the valve cover that has me a bit worried...Inside the timing chain's cutout in the valve cover, it looks like there is a large scratch mark in the metal, like the timing chain has been rubbing it. :eek: I didn't have time to check the chain stretch, but I will ASAP!

No. Tight valves open early and close late.

I was half wrong and half right.