Auto gearbox AL4 symptoms - meaning?

[CitroJim]

I haven't changed it. I am about to tackle that. I've noted your inspection points, which are going to be useful.

OK, that has to be carried out before any further diagnostics can take place.

Rule one with a misbehaving autobox - change the fluid...

[John Plum]

I noted the brand change from ESSO 71131 to Mobile LT71141, and dubious thoughts about it.

Can you confirm I've found the right oil here: ESSO 4HP20/AL4


Citroen main Dealer (Lookers), 'never heard of it' : a newish dealer I heard. They say they 'may be able to order it' and got back to me with the news that it is still esso oil that's listed in 2 litre packets, at £17.08 ex VAT each: the ID No. is '4HP20/AL4'.

Xantia sounded like a mysterious foreign word to them, and AL4 gearbox didn't seem to mean anything to them.

Local Peugeot dealer Robins - well established - straightaway said Esso 4HP20/AL4 in 2L bottles - 'we use quite a lot of it', and it is in stock. (£16.32)

[John Plum]

A lexia session should improve the accuracy of your diagnosis.

My guesses would be either an over-temperature fault, or a slippling clutch: the ECU compares the input and output rotation of the transmission, and throws a fault if the ratio is wrong for the selected gear.

Does the fault reading under these circumstances register a lexia fault, and if so , which?

[John Plum]

LT71141 looks like engine oil and smells like cat's pee. DEX has neither characteristic. It is dark red in colour.

Whilst you're there, smell the oil for a burning, toasty aroma and look at it critically, it should still be quite a nice amber colour.

NO burning aroma. SMells a bit like cat's pee. I'd say it never was just red, BUt I can't be sure what mix it is.The whole body of 3 litres in the tray looks dirty. Against the light, you might say amberish, If you really want to see amber... and try hard.

DEX is a LOT thinner and weaker than LT. LT has a lot of body and stickiness about it.

Difficult for me, I've never seen the consistency of DEX.

Yeah , I'd say this is thin anyway, compared to engine oil. The new stuff from Citroen, seems thin also: I wouldn't say that new lot (ESSO: HP20/AL4, with the Citroen badge all over, and checked against old LT specs) has a lot of body, or is sticky really either, but slippery. It is amber.

I would say castor oil is sticky and has body (is more viscous than others). I don't know these synthetics well, or the old spec AL4 oil, so I can't draw a distinction there either. It's thinner than engine oil, even new.

Anyway, I've emptied 3 litres. I'll be filling up and test driving it on a long run, after the weekend, and fitting a new drive belt tensioner roller. Cross fingers.

[xantia_v6]

A lexia session should improve the accuracy of your diagnosis.

My guesses would be either an over-temperature fault, or a slippling clutch: the ECU compares the input and output rotation of the transmission, and throws a fault if the ratio is wrong for the selected gear.

Does the fault reading under these circumstances register a lexia fault, and if so , which?

I only have direct experience of the 4HP20, but on that, I think anything that triggers 3rd gear limp home mode will leave a logged fault. On my 4HP20 when it had the wrong diff gears fitted, it would log the gear and RPM where it detected the ratio fault.

[John Plum]

On my 4HP20 when it had the wrong diff gears fitted, it would log the gear and RPM where it detected the ratio fault.

Then, (my dear Watson ), with no ratio fault reported by the lexia and, given the feel of performance when pulling away, clutch slippage (a worst fear) is less likely.

(sorry no emoticions of Sherlock Holmes or even a pipe smoker, plenty of bums and tits... which I suppose, does reflect the contemplations of modern civilisation)

[John Plum]

This may all turn out OK.

[lexi]

Both Dexron and Esso go a dark brown /black colour with too many miles on it. When fresh the dexron is a good red and Esso more like engine oil colour. I suspect that the Esso fluid may be a semi synthetic. I am still getting it about £15 for two litre from main stealer.

Have stockpiled some :lol

[John Plum]

dark brown /black colour with too many miles on it

.

That's how it is, the colour, with me.

[CitroJim]

John, have you refilled and tested yet?

Don't forget you'll need to visit a Lexia owner to have the oil wear counter reset. Take a note of the counter reading before reset. Lexia will tell you the maximum permitted value and and your old value before resetting. The count will give you a good idea of who knackered the oil was.

The reset can only happen with the engine stopped. Trying to do it with the engine running will lock up the Lexia.

The reset is important as if the count is very high, the fault may remain, even with new oil.

[John Plum]

Hey Jiim,

thanks so much for that information. It's really what I needed to know, to avoid confusion and consternation. Most Grateful for your sentinal watch.

I have refilled and tested the level. On testing the level the oil still looks dirty... guess I'll have to empty and refill again in due course. Altogether 3/12 liters to get it refilled. But I think I'll just chuck the remaining 1/2 litre in and check level again, just to be paraniod.

Around town it seems ok, but generally it did anyway, so I can't give a progress report, just yet.


BTW: Tenioner Bolts
-----------------------
I also replaced the belt roller so I can properly test the car on a long motorway run, on Monday, I think.

That roller actually seemed about OK, but the large central main bolt was cracked almost to seperation by now: it was the old bolt from the previously damaged tensioner roller that I inherited when I bought the car. Unfortunately the new roller I bought back then came without a new bolt and washer, so I used the old... A useful warning I think.... don't reuse the bolt on a collapsed tensioner roller, they would have had a bad strain on them.

[John Plum]

Magnificent.

Road tested around town, and then finally got a good run with plenty of motorway hills for 200 miles today. Behaving nicely.
Thanks to all for keeping an eye on me.


I conclude it was old oil that sent the pressure warning ( level ruled out on test). All in all I've replace 3 litres and 700 ml, with up to 100 ml wasted.
Upon rechecking the level, I find the oil looks dirty though, still. So I plan to replenish with another 4 litres within the year.

My impression then, is that this AL4 oil pressure sensor/warning is quite sophisticated if it detected a change in the oil's viscosity. Renewing half the oil has restored peace.

The problem had persisted after resetting but before refilling, but not after replacing without resetting the ECU fault. I presume the ECU re-set itself by taking a reading (not confirmed by a lexia session). All in all, this would go to prove that the 'oil for life' claim, is a contradiction with the actual setup of the gearbox ECU!

I was well biting my lip for while on this one, in a relatively unknown vehicle, until I had posed a few questions, after which, though no clear assurance of anything... my pulse rate dropped, even before re-filling. I started to communicate with the xantia as a whole, like it was asking for understanding, and I kind of kind of understood it. Even before road testing, I felt remarkably less untroubled.

I'm beginning to feel much more at home, and appreciate the build as it all comes together.

[CitroJim]

Excellent news john I'd do another partial change sooner rather than later though....

[John Plum]

Yeah I'm delighted.

I'd do another partial change sooner rather than later though....

Yes point taken.... as I see from further reading relevent posts. Thanks.