Mysterious oil loss

[MPV]

I've got a Citroen Synergie 1.9 TD (not HDI) and about 12000 miles ago I had the cylinder head changed, due to gas blowing into the cooling system. The car has only done just over 100K miles.

After the cylinider head was changed it used a bit of oil as expected, but instead of improving, the oil loss has gradually got worse. It's not leaking out anywhere and there is a bit of blue smoke, but not massive amounts, except on starting.

However, I'm now using about 1 litre of oil per 100 miles!

I've had it looked at by the garage I normally use and they are mistified too. They have checked the turbo seals and they seem fine.

Anyone have any ideas?

[spider]

Welcome

Its not going into the coolant is it ?

If its using that much, there should be signs of it, either in the coolant, visible external leaks or an excess of smoke from the exhaust (it will be bad if its using that much)

[MPV]

No, it's not going into the coolant, that was the first thing I checked. No change there at all. No sign of any significant leak. Get a lot of blue smoke at start, but once running, don't see mcuh smoke at all. At 70 mph on the motorway it runs nicely and no smoke screen!

[Xantidote]

Well that's some oil loss! Got to be going somewhere.

Was the replacement head new, or a recon? How many miles has the engine done? Does a blue haze follow you?

[dnsey]

Is there any top-end clatter, particularly when cold?
Was the replacement head reconditioned, or just second-hand?
I'm wondering if the oil's going down the valveguides.

[MPV]

It was a brand new head. The engine runs well most of the time, but is sometimes hesitant when accelerating, sometimes gives black smoke. And it's dificult to start from cold.

But no, at 70mph, no blue haze...just big blue smoke screen when starting.

Is there any way of telling if it's the valve guides?

Engine has done 103K to date

[HDI]

Blue smoke on start up is the give away, it's getting down the valve guides so probably the stem seals.

[MPV]

Blue smoke on start up is the give away, it's getting down the valve guides so probably the stem seals.

Is that likely with a new head?

[jimleshed]

Just a thought. Does it use more with continuous running (IE 100 miles trip) or various stop start trips, a few miles each? or no difference between the two driving types.
not sure where I am going with this though, just trying to get a few clues...

[CitroJim]

Is that likely with a new head?

It is possible if whoever built the new head forgot to install them. It's not hard to do as they are not very obvious sitting hidden right at the bottom of the tappet wells. Unless you know, they're easy to miss...

[HDI]

Blue smoke on start up is the give away, it's getting down the valve guides so probably the stem seals.

Is that likely with a new head?

Easily possible !! I fitted a re-conned engine to our works van once and it had symptoms of head gasket failure when we started to use it. I had broken my personal rule of checking everything not done by myself so failed to reveal that they had not torqued the head bolts !!!
When I checked the engine properly I found loose exhaust manifold bolts and incorrect pump timing too !!

[MPV]

I spoke to the garage about it being the head and they said there was no way so much oil could be lost through any seals in the head. They say it's because I used poor quality oil and it's damaged the oil seals on the piston rings.

I don't believe this, since I only used "cheaper oil" after the oil consumption became excessive and then only about a couple of litres...and when I say cheaper oil, I mean Halfords own brand for diesels...still nearly £20 a time!

So now I'm stuck with a car I've spent a huge amount of money on over the last year and will probably have to spend a lot of money on again to get a recon engine and get it running properly again.

Is it a difficult job to take the pistons out and change the rings? Can this be done from the bottom of the engine witout having to take the head off?

[jimleshed]

If there are no seals on the Valve stems you can lose quite a lot of oil, more than if they were just worn. But, unless you are lucky, the only way to see if they are missing is to strip down the Head.
Likewise with the Piston rings. You can do a compression test to check the state of the rings (or get one done) but it may not show if the Piston Oil scraper rings are shot and everything else is ok. The only thing that will do that is a strip down and check, or possibly an endoscope down an injector hole (if there is space) to see if there is excessive fowling in one or more cylinders.

Independant advice/testing is what you need to save you money.

I dont know if you can change the rings on a citroen without taking off the head, I know it can be done on some cars, (seen it done on an Anglia I think), it depends on the throw of the crankshaft: but probably quicker and easier to lift the engine out.

[MikeT]

I don't mean to sound patronising but you're not overfilling the oil are you?
Who told you oil-loss is to be expected after a head rebuild?
I'm also suspicious it really was a new head too. How much did it cost?

[MPV]

No, I've never overfilled the oil, I always run a little below the full line. This is far beyond the running in the head, have done about 8K miles and oil consumption is now around 3 litres for 150 miles.