Another XM in Australia

[Dieselman]

Now this wouldn't be too bad, except that I have a couple of 4HP20 documents that are in agreement - the correct amount to be added should be about 3 litres, and Mike drained and refilled 4.75 litres each time!!!

So it appears that when the repaired transmission was reinstalled, they overfilled it. According to the documents I have, overfilling is better than underfilling, as underfilling can destroy the box. Overfilling will 'only' cause the fluid to overheat (and possibly leak out) - and guess what! Overheating produces thumps!

So far I've only changed the fluid once - and found that I couldn't undo the level plug - the centre had been reamed out. Ordered a few seals, plus the auto drain and level plugs.

If the box has a level plug, I would expect that to be the level...
Auto fluid levels are normally set with the engine running, which probably accounts for the extra volume you found in your gearbox.

If level setting is by the plug, then I think the procedure would be to slightly overfill the gearbox, seal the level plug orifice, run the engine and cycle through all the gears and wait until the ATF is at 45c, remove the level plug and watch for a spitting dribble. Fit the level plug, then switch off.

[DownUnderXM]

Ahh, but that's the problem - as I mentioned somewhere, the centre of the level plug has been reamed out, and I haven't been able to remove it!

Presumably the previous owner struck the same problem, but thought he had found a fool-proof work-around. Measuring the amount that came out should have been a good approximation - except that the garage that did the previous fluid change put in 4.7 litres instead of 3 (obviously they didn't bother with the level plug either ).

My guess is that the workshop saw the figure 4.7 litres (which is the amount left after draining), and didn't actually read on to find the actual fill amount.

I did try to buy a genuine new level plug - but that was the one item that the dealer couldn't get for me. I'm not game to really attack the old plug until I have a replacement.

[Dieselman]

Have you searched under either Citroen or ZF part number.
Do you know the size.
There is no shortage of dead HP20 to recover one from.
Maybe an auto gearbox specialist can supply.

[White Exec]

Couldn't immediately find a part number for the HP20 level plug on Parts, but there were still available two "gasket kits" for HP20, which included both level and drain plugs:
2299 58 (mainly external washers and seals)
2299 55 (a larger kit)
Can post parts diagram if needed.

If you could get the old plug out, maybe possible to just weld a nut or bolt-head into the top of it?
Presume the hex/torx/square hole had been mangled.

[xantia_v6]

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.

Alec

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.

[xantia_v6]

I think that the transmission level plug has a M12x1.5 thread, and is probably common to several models of transmission (but that is based on information gleaned from the internet, and may not be reliable).

[DownUnderXM]

Dieselman - unfortunately, as far as I know, we don't have an auto specialist in this town, although that is something I could follow up next time I'm in Sydney. Now if I could just find someone to post me one from a dead 4HP20, I'd be delighted!

Chris - thanks, that is gold. If I'm right about my transmission leaking oil (& it's not from the banjo connection), then sooner or later I will need that kit! BTW, yes, pretty certain it was a Torx-shaped hole - T45 I think.

[DownUnderXM]

Thanks xantia_v6 for the reassurance about the ES9J motors - I knew they were a good motor, but that is a very good record!

If a significant amount of oil was getting onto the exhaust manifold, surely I'd smell it before it got really dangerous? From what I can see, it's not too bad (yet).

The oil in the wells was black (the engine was well overdue for an oil change), and if I had spilt that much while filling or topping up - well I'd be too embarrassed to own up! Let's just say the spark plugs were never going to rust . OK, so the crankcase is not usually pressurised, but is there a PCV valve? Perhaps mine is malfunctioning?

I know there is a complicated octopus breather system, and I suspect it is not entirely air tight - idle can be a bit rough, and sometimes the engine stalls while warming up. Is the PCV valve somewhere in that octopus?

[karuzin]

I don't know how much you paid for this XM, but it makes mine perfect condition in comparison, and the $400 I paid, including the spare car, makes it more the bargain. The only thing wrong with mine was the arm rest cover was loose. I have fixed it easily enough. I hope you return it to perfect condition for an affordable price.

[DownUnderXM]

So are you going to show us some photos?