Oil Pump

[Jim Haseltine]

After a struggle (understatement) which involved the use of every swear word I know in at least 3 languages I have got the oil pump off my car. Judging from the mucky oily deposits on the rear of the pump, it looks very much like it wasn't the O ring that was leaking, more like the pump seal. The shaft tube is quite tight in the O ring but the seal is slack. In my opinion there is something of a flaw in the design of the seal socket on the back of the pump as the shaft tube seats only a few mm deeper than the seal whilst it seats around 1cm past the O ring. Mind you, I'm not an engine designer so what do I know?
I'll know more once the new parts have arrived. The O ring flange is sealed to the chain drive with some sort of sealant which I assume is the same as VAG use on timing covers and the like - can anybody confirm this?

[Jim Haseltine]

Now measured - O ring seat: 7mm below O ring
Pump seal seat: 3mm below seal.

[ATinOf]

A photo would explain Jim, struggling to picture what you are describing?

[Jim Haseltine]

A bit out of focus, this is with the shaft pushed as far into the pump and the O ring as possible.

1 is the oil pump end, 2 is the chain drive end (O ring).
It might be that the seal has been fitted too deeply into the pump, but it doesn't look like it to me.
Anyway, looks like I've been wasting my time doing things this way, I've found a considerable amount of oil running down the RH rear of the engine, looks like it's either coming from the rocker cover or the rear cam cover. Guess the engine will have to come out after all which will be fun as it'll probably mean swinging two immobile cars through 90 degrees because even if I roll the RS back as far as possible I've only got around 5ft to play with where it's parked.
Still, it'll give me the chance to sort out the turbos, although breaking the news to my other half is not something I'll do before she's had a few glasses of wine.

[Jim Haseltine]

And, as I've just discovered, the 'seal' at the back of the pump isn't a seal - it's another O ring.

[Jim Haseltine]

And, as I've just discovered, the 'seal' at the back of the pump isn't a seal - it's another O ring.

And priced at over a tenner is taking the p*ss somewhat.

[ATinOf]

Now I follow you, long shot I know but is it possible someone has already had a go and not fitted the correct seal if its slack in its recess?
I had this job done for me on mine and is noteworthy they replaced the shaft as well as the seal.
On traditional oil seals (lip and spring) you can play with the depth of seating the seal to a small degree to get a replacement seal to 'sit' on a 'fresh' part of the shaft (to move it from the 'warn' part) to improve the seal,but you cant do this with O-rings.

You may have already but asking the obvious before you look to remove engine, have you checked other leak sources for your RH rear oil leak, as in RH rear cam solenoid, oil filter housing, and oil cooler mounted to the top of the engine valley under you inlet manifold (is your valley flooded)?

[Jim Haseltine]

I've been around with an inspection light and a 'scope this afternoon, the valley is dry. The cam solenoid is a possibility, as it was replaced shortly before I bought the car (3 years back) and the amount of dirt and oil in that area could well be 3 years worth.
With the pump, there's a drive shaft and a static outer cover - it's the seals at the ends of the cover that leak. I'll see how tight the new ones are when they arrive.

[Jim Haseltine]

And having said all that, I've just tried to remove the other O ring (the 60p one) - without luck, it's rock hard, suspect it'll come out in pieces.

[Jim Haseltine]

And it did:

no flex in it, it's like a piece of hard plastic.