Citroen c3 1.2 burning oil.

[studabear]

My pals car has failed MOT on emissions, low lambda high co at fast idle.

He asked me to have a look today, I thought I would scan it and see if reseting adaptions would help. I've had several cars where reset adaptions has got them straight through Cat test.

So as I drove it towards the gas analyser I thought I noticed the oil light flicker. Our usual scanner has locked out, so I borrowed a Snap on Solus, this couldn't find an exact match for the vehicle but I tried the nearest match and did find a code for cyl 3 misfire. Deleted that, stuck it on emission machine and still way out on the lambda and co. So I thought I better check the oil on this, dipstick bone dry, took 2 litres to get it into the middle of dipstick. Tested the emissions again at fast idle, only now its pluming smoke out the tailpipe too.

Told my mate I had put 2l oil in and he said he only topped it all up on Thursday. (Been Scotland and back to Blackpol afaik)

Mileage isn't particularly high on the car, seems to have been cared for. Just wondering do these have any breather issues or do they suffer with piston rings etc to anybody knowledge? Engine code is HMZ if it helps.

[studabear]

Just to add its seems to be sucking the oil cap on or if I removed the cap with the engine running it makes a sucking/vacuum sound and pulling the cap back.

[chippie]

May 22, 2023 20:52:47 GMT 1 studabear said:

Just to add its seems to be sucking the oil cap on or if I removed the cap with the engine running it makes a sucking/vacuum sound and pulling the cap back.

A stab in the dark here….
Crankcase ventilation system not working properly? Oil mist being sucked into the inlet tract… that would give rise to lo Lambda…?

[studabear]

A bit of online searching suggests these are rife for burning oil, sometimes from faulty pcv causing carbon build up.

[OldGit]

There was a 'thing' with these having crankcase vacuum and burning oil, for the life of me I can't remember what - possibly the valve in the crankcase breather (new rocker cover required) but TBH it was 6-7 years ago...

You could try clamping off the breather and see if the crankcase goes from negative to positive pressure at the oil filler cap.

[studabear]

Emissions are fine with oil cap removed so I guess its new cam cover time.
Although I may have found a repair kit on ebay.
Cheers.