Leaky Head Bolt - 280SL

[PeterW113]

Morning all,

After a few years of neglect I have finally got around to starting a few jobs that had been pointed out to me.

Having been told that the crankshaft seal is leaking I commenced stripping the front of the car, radiator, grill etc,.  Days previously I had cleaned around the front of the cylinder head during a successful 123 distributer installation.

However, I now can see a lot oil freshly leaking from the top right of the head.

The bolt in question, looks like it has something to do with the timing chain. I have studied the Haynes Manual but cannot work out if it is safe to remove and replace the washer / seal of the said bolt.

As always the Forums guidance will be greatly appreciated.

Cheers

Peter

[ja17]

You are safe to remove this. It is simply a cap which covers the opening that the chain idle sprocket pin slides into. Use a new seal and a little thread sealer on the threads of the cap. Most likely the cap is loose. This is not normally a common source of a leak.

[PeterW113]

Joe

Thank you so much for your quick reply, I was worried that I might disturb something related to the timming chain and never be able to refit it without taking even more bits off.

Regards

Peter

[PeterW113]

The plug was loose and it looks like the aluminium washer had not compressed in any way.

I am now beginning to think this is the cause of the oil leak on the front of the engine and not the crank seal?

I am in two minds now as to wether to carry on and replace the crankshaft seal which seems to be quite a challenging job, or just clean everything up and put the car back together.

That way, if the leak persists I will know it is the crankshaft seal as well.

Peter

[DaveB]

That sounds a good approach. But does the oil from this leak extend all the way down? No doubt you've had a look already so I guess it's inconclusive.

Perhaps you should seal that head bolt and clean up the oil before you reattach the front end parts. The leak should reappear fairly quickly if it's the crankshaft seal. At least mine does, though it's the rear (I think, I should also look for leaks higher).

[PeterW113]

Thanks Dave

This is what it was like before I cleaned the plug and head and the oil ran all the way down. The previous pictures were taken after cleaning during the installing the 123 Distributor and running the engine for a short while. I am hoping that this is the sole perpetrator.

I have cleaned the crank seal and I am watching it very carefully for seeps whilst I replace the engine mounts and power steering hoses.

Fingers crossed that I see signs of the crankshaft seal leaking before the radiator goes back on.

Cheers

Peter

[DaveB]

Yep, fingers crossed - that you've already fixed the problem and you do NOT see any crankshaft leak.