5 Cyl Diesel valve adjustment 1980 300 SD

Feb 25, 2004 5 Replies

I have a 1980 300SD with about 240k. Lost lots of HP recently, barely got home. Neighbor who is German car mechanic says check valve adjustment. Question, anyone know what special tools are needed to do a valve adjustment on this engine? And where a good place to purchase them? And while I am asking, valve lash?



Any help would be appreciated... Thank You!


Likely culprit here ius clogged fuel filter. Bill Ditmire Ditmire Motorworks,Inc.

425 White Horse Pike Absecon,NJ 08201
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If the power drop was sudden BUT the engine still starts easily then the valves are NOT the cause. Not to say that a valve adjustment isn't needed but it would not show such symptoms.

By power drop I suppose you mean poor acceleration. If that's the case here are some possibilities, in order of likelihood:

When were the two fuel filters last changed?

The engine's air filter last changed?

Clogged banjo fitting or cracked hose. The turbo's boost is piped over to a fuel enrichment device inside the injection pump. This is done by a plastic line that starts at the aft end of the intake manifold. There is located the "banjo fitting" and hollow bolt. Remove the both and clean out the bolt and the banjo fitting with a paper clip wire. Then follow that line over to the left side fire wall to the "switchover valve" . Be sure the rubber connections to that valve are intact. Then follow the plastic line to the injection pump again ensuring that its intact and correctly connected.

I've owned the same model since new, nice car.

And if you decide to check and adjust the valves, the wrenches are available on Ebay.

des ventilschraubenschlussel des fuhrer

or seriously, you can search for "mercedes valve" on ebay. Hazet is the german brand, I've also seen others on there.

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