1.4hdi strange oil leak

[xsaras4ever]

Hello to all.

In another topic we mentioned that our 1.4hdi was running on 3 cylinders. Its a 1.4hdi - 8 valve.

The problem eventually turned out to be the valve rockers.
6 were worn to hell and back, 1 was good and the last one was so worn that it fell off and stopped operating the valve.

In the process we broke a glowplug, so we took the head off to drive out the glowplug tip.

New head gasket.

When torqueing it up, we only did 60degrees of the final tightening sequence because it felt like the the bolts were about to snap. We were literally swinging out of the torque wrench with all our force.

The engine went back together with new sealant on the 2 aluminium casings that hold the camshaft and a new gasket on the plastic rocker cover.

It started easy enough and we were letting it idle and after 20 minutes it began to drip oil.

Its on the timing belt side and we took off the top timing cover and traced the oil up to the head and up as far as the top of the engine mounting - which is above head-gasket level. It did not appear to be coming from the camshaft seal.

We had not been happy with the way the plastic rocker cover went on , so we took it off and refitted it.

Same problem again.

There is a certain amount of pressure when you remove the oil filler when the engine is running - more than we expected but we are comparing that with the older A-series engines from minis that we are familiar with.

We stripped down again , including the camshaft casings (we are going to fit a new camshaft seal)

On looking at the casings , all the sealant appears to be good and un-broken.

Looking sideways at the head there is a casting which appears to have a ball bearing in it - is this some sort of pressure release or nothing to be concerned about ? (its not the hole where you lock the camshaft)

Its going to get a new timimg belt as the old one (only done 25k) is oil contaminated.

The engine sounds tappety - but it always did and so did the 1.4hdi in our 206.

Bit wordy this posting - sorry - wanted to give as much info as possible.

Done heaps of work on this car and a bit fed up of it.

Answers in the post please with a big can of petrol and a box of matches

[CitroJim]

That's most odd. I cannot offer anything substantial but I will say the ball bearing is likely to be a casting oil gallery closure device. It would have been inserted straight after the casting was made to seal off and make it a blind gallery...

Think of it as a kind of core plug... They rarely leak but you never know...

The reason for their use is that blind galleries cannot be reliably cast and having them initially open makes them easy to cast and the mould easy to remove afterward...

It used to be used a lot on carburettors back in the day...

[xsaras4ever]

Thanks Jim - that rules out that.

Stupid question probably - but has to be asked.....

There is a hole behind the camshaft oil seal on the lower alu casting that holds the camshaft.

It goes directly into the chamber to the valve rockers.

If we have too much pressure in the engine, would it vent there and carry oil with it ?

BTW - those head bolts will not tighten any more - no way - but they are not new.....

[CitroJim]

There is a hole behind the camshaft oil seal on the lower alu casting that holds the camshaft.

It goes directly into the chamber to the valve rockers.

That's an odd one The cam box is an oily place and the cam journals will be pressure lubricated... A hole by the seal will definitely let oil out...

[xsaras4ever]

Hello all.

The first image is the "blind casting". If you look closely you can see a tell-tale oil mark on it, its just below the camshaft seal so we hope thats the problem.



In this photo it shows the hole behind the camshaft

https://imgur.com/a/vjunm

[xsaras4ever]

There is tumble-weed blowing through this posting...........

[CitroJim]

There is tumble-weed blowing through this posting...........

I will do my best to blow it away!

The hole you speak of appears to be on the internnal side of the seal so that's right as tit needs a drain-back there to prevent any build-ups...

[xsaras4ever]

Thanks Jim.
Will fit the new timing belt today and see how it goes.
Any ideas on the pressure inside the engine. Normal or not ?

[CitroJim]

Any ideas on the pressure inside the engine. Normal or not ?

In the cambox the pressure should be low but volume will be high as oil flows out of the bearing journals in the normal course of lubricating them...

Are you concerned that blow-by may be pressurising the crankcase? If excessive this can cause leaks everywhere and even blow the dipstick out!

[doctle]

Did you ever get this sorted?

[xsaras4ever]

Hopefully today...............

[moizeau]

Sorry if I'm talking absolute cobblers, I don't know this engine at all but...
What's above the engine mount? A plenum? If so is it full of oil? Was the car started with everything put back in place? If so remove everything to expose the rocker cover and see where it leaks from. The fact that the original problem was worn rockers would suggest a lubrication issue. I had a Polo years ago that would fill the air box with oil until you turned a corner and it would come out the exhaust. That was due to a blocked crankcase breather, or rather the gauze inside it.
Best of luck

[xsaras4ever]

Hello to all - not got it back together yet - not enought time at the moment.

Yes , we are concerned that pressure inside the rocker cover is putting the seals under pressure and forcing oil out.

https://imgur.com/a/D5dle

On the red arow in the pic above - we washed petrol into that pipe on the rocker cover (rocker cover off) and it ran nicely down to the oil filler neck chamber. When we put petrol into the oil filler chamber it would not run in the opposite direction - ie: out at the red arrow.

Seems to be some spring loaded gadget in there.

Can some clever person enlighten us please ?

[CitroJim]

A one-way valve... Intentional and known as PCV valve or Positive Crankcase Ventilation. It is intended to suck fumes out of the crankcase into the inlet tract (running a small depression) to burn them but stop the inlet pressurising the crankcase when the inlet depression is not present or has gone positive with respect to the crankcase...

Yours would appear, from what you say, to be the wrong way round and that would potentially pressurise the crankcase... Make sure it's the right way round...

It was the very first emission control as before this crankcase fumes (containing lots of unburned hydrocarbons and other nasties) were simply vented to open air... A major cause of pollution.

[xsaras4ever]

Hi Jim and thanks for the explanation.

If we understand you correctly - fumes can flow from the rocker cover INTO the air-inlet pipes and turbo - - BUT - will not pass the opposite way.

Therefore, the petrol flow that we describe is at odds with the design.

It smells like a red herring maybe - because it will all probably operate correctly with the engine running and sucking blowing etc.

It appears to be a sealed plastic unit so cannot really have been turned the wrong way around - or can it ?

The engine had 150,000km when we fitted it and we did about 20,000 more.

Its a bugger that the rocker cover is so large on this engine as it obscures any chance of spotting the leak when the engine is running.

It might end up in us fitting the new camshaft seal and the new timing belt and testing again.

At 20euros - the loss of another timimng belt isnt a disaster.

Its not having the car and it blocking up the garage is the bigger problem !!!!