P208 XY with 1.6 THP (115kW) oil consumption and leak

[Gregor]

Hi.

So I have a car with 102kkm on the clock and it started to eat a lot of oil. I have to sip 1 liter every 850-900 km! Also the fuel consumption increased dramaticaly. Oil is also leaking on all gaskets around valve cover, which is very strange to me as when you open the oil filling cover, air is getting sucked in (so vacuum inside)... My mechanic claims that piston rings are gone, but I can hardly bellive that since the car is well mainteined and driwen by my wife very gently, mostly on relations of 60-80 km. When I open an oil cover I can also hear some unusual ratle, but not like usual loosen timing chain noise. I was thinking if this could all be related with lost timing or intake valves beeing not able to close fully because some obstacle (carbon on stems?). Any Idea is higly appreciated.

Cheers Gregor

[Muir]

Sounds a lot like a defective PCV valve, especially since you have vacuum in the valve cover rather than pressure.
If that's the case your turbo is sucking oil directly from the valve cover into the intake.
Try removing the intake hose right where it connects to the turbo. There will always be trace amounts on oil inside the pipe and turbo impeller, but if theres lots that's most likely you problem.

[Gregor]

Thank for a sugestion.... Meantime I found the hose conected to turbo inlet broken. So turbo didn't suck from filter but free air. So also not the oil from valve cover.... Waiting for a replacement part at the moment and then we'll see. Turbo impeler is untouched and no free movements in any direction. No traces of oil in tubes. At least that looks nice!

[Muir]

you're welcome, glad to hear it was a fairly simple issue

[Gregor]

Update: Oil consumption halved, but still too big. aprox. 0,5 lit/1000 km. Can carbon soot/deposits on valve stems cause valves not to seal completely? Causing some pressure/vacuum issues under the valve cover? Anybody knows something about that?

KRG

[PaulC5]

If the THP engine is related to the vti engine then it might be badly designed and use oil - we had a 1.4 vti C3 that used a lot of oil and that was from when we got it at 12000 miles. I can not remember how much but it was possibly 0.5 to 1.0 litres per 1000 miles.

[Gregor]

If the THP engine is related to the vti engine then it might be badly designed and use oil - we had a 1.4 vti C3 that used a lot of oil and that was from when we got it at 12000 miles. I can not remember how much but it was possibly 0.5 to 1.0 litres per 1000 miles.

It is related and we all know it is a bad design... (darn BMW influence on French engering!) But I still don't belive that It can jump from minor oil consumption to enormous by worn out piston rings all the suden. Especialy when engine is a normal starter, no smoker and pull like it should. Driven from new by now 50year old lady, with services done on 12 months interva and max. 8000 km betwen oil changes.

What about PCV valves, can they cause simptoms like this?

[xantia_v6]

Yes, the PCV valve on the hose going to the manifold can fail, causing too much air and oil vapour to be sucked into the engine.

[IRAs308]

Found this thread - I've been looking for reasons for the high oil consumption on my 2012 308 EP6CDT 5FV 110k KMs (approx one litre every 500k).

No oil smoke from the exhaust. Using Peugeot spec oil 5W30 B71 2297.

I had the timing chain replaced about 300k ago (badly stretched)

I'm on my 3rd rocker cover.

The 1st one had the PCV valve fail.
The 2nd one fractured around the central bolt that supports the rigid turbo to intercooler pipe.

Reading this thread high oil consumption can be attributed to a faulty PCV valve, with the symptoms of a vacuum on the cover tested by covering the oil cap hole with a piece of plastic. Pulled in = vacuum, pushed out = pressurised

My 308 shows vacuum - I have not yet pulled off the turbo inlet to check for oil contamination.

I am after confirmation that the cover should NOT be producing a vacuum from you the contributors to this site, as I am getting confliction info from Google searches, before I go ahead and pull off the inlet pipe, check for oil and order a new cover.

Thanks in advance.
IRA

[Gregor]

IRAs308... Can you give some update on efect of valve cover replacement?

[IRAs308]

Hi Gregor,

I haven't ordered a valve cover yet.
I found my turbo intake pipe was broken and oil contaminated so I have ordered a new one.
Christmas has caused parcel delivery delays so it may be after Christmas when I have completed the repairs.
I will update this thread when I have new information.
Cheers

[IRAs308]

Well, Christmas and new year is over and I finally have an update.

The engine cover and air intake pipe have been replaced, and compression tests have been performed.

Unfortunately the results are not what I wanted!

From Gearbox end:

1 - 134
2 - 143
3 - 140
4 - 60 - bugger!

Also the plugs were fouled (burnt oil deposits? - I didn't take a photo of plug 1 as I had already screwed it back in and couldn't be arsed taking it out again, as I am doing the work in the open, weather here has been either too hot or wet to do work on car.)

Oil consumption was 900ml for 572 km.

I think I need to take it to my mechanic - (clutching at straws - maybe a valve clean??)

[xantia_v6]

Not looking good. I have no good answers but a carbon clean of the valves will not reduce oil consumption. If the 60 psi compression pressure is real, then I suspect a problem with the rings (gummed up?) is causing severe blowby which then carries lots of oil vapour back into the engine via the PCV system.

I suppose you could try adding some kind of "snake oil" to the oil to try freeing up the rings, but I am wary of such products in a turbocharged engine due to the high temperatures in the turbo and the need for good lubrication.

[PaulC5]

Cylinder 4 could have valve/seat damage or head gasket. Possibly the valve guides are worn and their seals need replacing. When you accelerate, then lift off the accelerator and then accelerate again do you get smoke from the exhaust which could be a sign of valve guide wear ? Also on first start getting smoke can be a sign.

If there is a smoke when just accelerating then that might be a sign of turbo wear - I had this on a Saab before the turbo failed.

When doing the compression test if a bit of oil is put in the cylinder does this increase the pressure - if so it is a sign of worn piston rings or damage to the bore.

I suspect the cylinder head needs removing and reconditioning.

[Gregor]

A little update...

Since it was getting worse in oil consumption, I decided and opened up an engine. WTF.. This engine is a real crap. Looks worse inside than R5GTt with 200kkm of hard life. This is driven by my wife, 50+ old lady with light foot, oil changes on 8-9 kkm (every year) and driven on higway for 70 km in one direction. Almost no short jorneys. Piston rings worn and cracked, black gunk everywhere (except on turbo). All seals cracked and hard as a stone ... Total dissapointment! It costed 1700€ in parts to get it going again and now fingers crosed that it will last for another 100kkm.