DownUnderXM wrote: ↑
Sat May 02, 2020 5:34 am
You must be in NZ at the moment
. It's to be hoped that Oz & NZ do mutually open borders before too long - we are itching to come over for a holiday.
When I bought the car, it was clearly well overdue for a service. In addition to oil & filter changes, I decided to fit new plugs. When I removed the coil pack, I was very disappointed to find that the front plug wells were full of oil, because Mike (PO) had told me that Jason Hantos (one of a dwindling number of Citroen specialist mechanics in Sydney) had sealed the cam boxes.
However the back wells were dry, so I was happy to just replace the plugs. I was girding my loins to attack the front cam boxes, when I got an interesting suggestion from a fellow Aussie Xm owner - he said that if the worst-affected plug well was below the filler cap, then it should be prime suspect.
This didn't make sense, as I had evidence that the oil filler cap was not very old. I had no idea how to get a replacement sealing ring, but decided to try fitting a couple of O-rings between the cap and standard sealing ring. Bingo - I rechecked after a couple of thousand km, and there was no new oil in the plug wells. That said, is it possible that oil could leak outward from those cam boxes without collecting in the plug wells? The sump seal is definitely a suspect, but I can see signs of oil coming from higher up - so perhaps the cam bearing block/head interface, or even the rear head gasket, is the problem.
Re. the 4HP20 banjo connection, I currently have it exposed while faffing about with the P/S ram. Seems perfectly dry, but I'm getting a slow drip from the bottom of the transmission - oil is collecting along the central seam. Am pretty confident it is not the drain plug. Actually, I'm confident that it's not engine oil, but I had better recheck whether it is actually LHM rather than trans fluid.
Thanks for your interest, and all your suggestions.
Yes, I am currently in NZ, for a while by the looks of it, but my Citroens are in France.
If the oil in the plug wells was clean, then it was probably due to spillage when filling the oil, that is easily done. I don't think there is much likelihood of oil being pushed out around the filler, as the crank case is not pressurised (unlike my Peugeot 308 THP where the oil escapes at the slightest opportunity from any suspect joint).
If the rear bank cam covers are leaking badly, oil can overflow onto the exhaust manifold, risking a fire.
I have owned 6 cars with these engines, one reaching 300,000 km, so have a fair experience of the common problems, but have never had a major engine failure nor head gasket problem. The only case I personally know of where a head gasket failed (not one of my cars) was probably because the cooling system was not bled properly after being refilled.