Oil Filler Cap Blowing Off

[Floyd]

Hi, discovered last week that my oil filler cap was missing on my 03 C5 2.0 HDI. Figured it was my oversight and got another from scrappers. Today car seemed sluggish then suddenly ok then my battery fault warning came on so went under bonnet to check connections and noticed oil everywhere (dripping onto alternator :( ) and oil cap missing again! Internet search seems to predominantly blame the plastic engine cover, which was loose to be fair, but the sluggish point earlier makes me think it's something more. Any ideas where to look would be appreciated cheers.

[coastline taxis]

couple of things check the plastic rocker cover where the cap screws in to make sure that its not broke. If thats ok then id be checking for back pressure on the engine

[paul.h]

Welcome to the forum.

How many miles has the car done and does it use much oil between services, possibly indicating worn valve guides and piston rings that could lead to excessive pressurisation of the cam cover ?

 

A few thoughts;

- was the replacement cap the correct one.

- are the pegs in place that the filler cap tightens up against.

- does the cap feel tight when it has been rotated in place and does it have the O-ring seal.

- the battery light is probably from the oil leaked onto the alternator, hopefully this will clean off and not result in damage.

- leave the engine cover off for now if you think this has caused the filler cap to rotate loose.

- the loss of power may be due to a sudden air flow in/out of the cam cover when the filler cap came off which would not be measured by the air flow meter.

- check the breather hose and connections between the cam cover and the air inlet piping are not blocked.

[Floyd]

Thanks for the replies guys.

 

 It appears to have been the loose plastic cover that caused the oil cap to unscrew (3 of the pegs were broken!). Sod's law dictated that my alternator had fried itself in the escaped oil since I broke down the next day which left me with a garage bill of nearly £300 :( Strangely since the repair I now have a lot of wheel vibration at 70mph, wondering whether the wheels being ratchet strapped to the breakdown flatbed could have caused any damage? Also the windscreen washers are now suddenly not dispensing water even though I can hear the pump working.....could something have been dislodged during the alternator replacement?

[Floyd]

Oh and joy of joys.....just nipped up to the shops in the car and it's displayed a "SERIOUS SUSPENSION FAULT" warning! I'm rapidly beginning to hate this car.

[Johndouglas]

Will the car still rise and lower on the buttons?

[coastline taxis]

a faulty alternator will give you loads of phantom faults. if you can clear all the fault codes and see if any come back. if you cant then do a bsi reset and see if that sorts it.depending on which way the alternator was removed a washer pipe could of be knocked off. open the bonnet and go the the drivers side hinge and youl see a black tube make sure its pushed into the bottom of the rubber strip that runs across the bonnet

[Floyd]

Jeez you guys are on the ball :)

 

 I'll check in the morning and follow your advice. Just googled the bsi reset and it looks to have more procedures than I had to go through to get married! Worth a go though since I used a good garage but not a Citroen main dealers for the repairs so they probably fixed the fault but wouldn't have done a tango with the Citroen computer ....which to my mind seems akin to having an argument with an ex wife!

[paul.h]

On the C5 technical subforum you will find a bsi reset as a pinned topic.

A wheel balance weight may have been knocked off on the flatbed - a check of the wheels may show a clean bit where a weight once was.

Also check there is still some water in the washer tank.