Valve seals

[Martinez]

Although my 2.0lt hdi engine runs well after 180K, it does seem to use oil. There’s a bit of smoke on startup which leads me to think it’s valve seals worn or gone hard. Anyone any experience of replacing them without removing the head ? I’ve seen videos on YouTube but any tips welcome

[Gadgetman]

The seals in my 1.4i (probably a 1997... possibly... maybe... The car is a 1999, though) were so hard and cracked that they fell apart in my fingers.
Odds are that yours are a bit beyond their best, too.

[Martinez]

That’s what I’m thinking, but anyone replaced them ?

[brajomobil]

What is the color of smoke ?

Best regards,
brajomobil

[geoff]

How much oil does it use ?

Personally I'd leave well alone until you have urgent work to do on the engine.

[Gadgetman]

If it leaks around the exhaust valve stem, it may be required to fix it soon.
Because the oil gets carbonised on the stem and will work as a fine abrasive, and slowly grind on it.

[oilyrag]

I've changed valve stem oil seals in situ, but only on a petrol engined car (non-Citroen). It is possible to buy an air compressor adaptor that , when the valves are both closed, allows you to keep the cylinder under pressure and stop the valve falling downwards. Saw it as high risk, so fed new sash cord into the cylinder and then turned the engine until it was compressed at the top of the bore and this held the valves in place whilst the work was done. 
Not sure how you'd do the same with a diesel and just how easily the valve collets can be removed though..... if a job is worth doing and all that. If the mileage is that high and there's been oil by-passing then a de-coke is possibly the favoured option.

[jj9]

A diesel cylinder head is flat with no combustion dome so if you get the piston to TDC on the cylinder you can compress the valve springs of both of the valves for that cylinder as the piston will stop the valves from moving down.

No need for any compressed air or rope in the cylinder.


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[oilyrag]

A diesel cylinder head is flat with no combustion dome so if you get the piston to TDC on the cylinder you can compress the valve springs of both of the valves for that cylinder as the piston will stop the valves from moving down.

No need for any compressed air or rope in the cylinder.


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Every day is a School Day for me!
Out of interest, how do you find TDC on the 'firing' stroke ?

[jj9]

Time up the engine before you start, this will put the pistons of cylinder 1 & 4 at the top, moving the crankshaft 180 degrees from this point will put the pistons of 2 & 3 at the top.

Or you could remove the glow plugs and use a thin probe.

Every day is a school day for everyone   

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