BVA 4 in MK1 vs BVA 4 in MK1 Facelift

[10mbc]

Hello,

I am considering buying a 2005 Citroen C5, MK1 facelift, 2.2 HDI 133PS with the 4 speed auto gearbox. I woul like to know of the 4 speed auto gearbox in this car is the same as MK1 without a faceflit, the one from 2001 to 2004, on the 2.0 HDI. I hear that the MK1 non facelift auto 4 gearbox is pretty unreliable and I should not get that but I am not sure on this one.

Thanks in advance!

[CitroJim]

None of the autoboxes used in any of the C5 models has any significant show-stopping reliability issues as far as I'm aware...

All are 'sealed for life' and do have a finite life but tend to be reliable enough until they get toward their natural end of life which can be any time after ten years and /or around 160,000Kms... They then tend to fail catastrophically. The 10 year/160,000Km figure was the definition of 'life' as applied to the 4-speed ZF 4HP20 used in the earlier Xantia and XM V6s and that 'box may have been fitted to some early C5s, possibly yours. Many went on for much longer, especially in diesel cars, before they failed.

The Aisin autobox fitted to later C5s has a known valve block problem at high mileages but is easy enough to resolve and can be done without having to remove the autobox from the car.

Do you have any information to substantiate your 'pretty unreliable' statement? I'm not doubting you, I'm just interested to know...

[10mbc]

I have not yet owned any automatic gearbox car so the "pretty unreliable" is taken from general conversation with other Citroen loving enthusiasts that I had a chance to talk over the years. Of course, the car has well over 160 000km, it's something like 220 000km on the clock (might be even higher in reality). Yes, the gearbox seems to be the 4HP20, I was not aware of the fact that that was the actual name.

I am not able to find any C5s for sale with the 6 speed auto box in my country, so I guess the option would be to get one from Germany or France or just get a 6 speed manual. Why I was attached to the car I am talking about was because of the trim and options: heated velour seats with lumbar support, stationary Webasto heating, stratified front windows, red color and so on.

Thanks for your input!

[Paul-R]

Can you ask the seller of the car if the gearbox has had the oil replaced at all? This would be a good sign the car has been looked after.

[10mbc]

I have already asked him that, he has not replaced the gearbox oil and has no records of it being replaced.

[reachren]

It's worth noting that just because a car has a high mileage, it doesn't necessarily mean that the gearbox will be close to the end of its life. It really depends on how well the car has been maintained and how it has been driven.

If the gearbox oil has not been replaced and there are no records of it being done, it's possible that the gearbox may be in need of some maintenance. It's always a good idea to have a mechanic check out the car and give you their professional opinion on the condition of the gearbox before making a purchase.

[CitroJim]

It's worth noting that just because a car has a high mileage, it doesn't necessarily mean that the gearbox will be close to the end of its life. It really depends on how well the car has been maintained and how it has been driven.

True and despite the 4HP20 being 'sealed for life' a regular ATF change using the correct LT71141 fluid and not a 'compatible' fluid will help to an extent. Also, a car that's regularly been used for short urban trips with frequent gear changes is likely to fail sooner than a car that's done lots of long, fast motorway miles with few gear changes... That's my experience from rebuilds and forensic examinations I've done in the past.

The usual failure mode of the 4HP20 is a blockage of the oil filter (inaccessible for servicing - the gearbox has to be completely stripped to get to it) due to debris from the break-up of the torque converter lockup clutch. The blocking of the oil filter causes a loss of oil pressure which leads to insufficient pressure to fully engage clutches and brakes which, in turn, cause slippage, over heating and further lost friction material. The end comes then there's insufficient pressure to drive and/or there's catastrophic bearing failure and oil pump damage from loss of lubrication pressure. On only one HP20 have I seen a valve block failure cause serious damage.

None of this can be easily predicted... The good news is that if caught quickly, the 'box can be rebuilt and made good again fairly easily... I've rebuilt five...

The ones I've rebuilt varied in mileage between about 120,000 miles and 200,000 miles... The 200,000 mile one being from a 2.2 HDi diesel believed to have been used in a former life as a long-distance taxi engaged in airport runs.

My view is that with the HP20, if it's been going for around 120,000 to 140,000 miles then expect it to fail in the not too distant. Regular fluid changes may hep extend this life a little as the act of changing the ATF may flush out a bit of circulating debris but the filter will eventually block wherever is done. Friction material wears over time as a natural part of the operation of the gearbox and this will put debris into the ATF and the filter.

Beware of 'boxes that have had the fluid changed for the wrong type. Genuine Mobil LT71141 is the only fluid to use and others, particularly supposedly compatible Dexron, may cause damage.

A good test, when looking at a car with this 'box is to drain a bit of fluid from the gearbox and both look at it and smell it. If it's black and smells like burned toast the gearbox has likely began to fail. If the fluid is still translucent with a light to dark straw colour and smells like rancid cat's pee then all is likely to be well.

However it smells, if it's red then beware...

[xantia_v6]

A 2.0 HDI (before 2008) is likely to be fitted with an AL4 transmission, rather than a 4HP20, which was fitted to the 2.2 HDI and petrol V6.

The AL4 does not seem to have the filter blockage issue that kills the 4HP20 at high mileage, but they do suffer from failure of the control solenoids.

There was was a change to the design of the solenoids to improve reliability. Fortunately the solenoids are not too difficult to replace without removing the transmission.

[CitroJim]

I suppose the AL4 - and likely to be what's in your current 2.0HDi 10mbc - could be described as having a bit of a reliability problem given its solenoid issues but this 'box is unlikely to be fitted to the 2.2HDi you're looking at. Designed for the smaller engines, the 2.0HDi was about the limit for it.

But for it tendency to block its filter, the 4HP20 is a tough old unit, built like a battleship and very amenable to overhaul...

A basic guide on how to rebuild them can be found here: https://eastment.net/4hp20/4hp20_introduction.htm

If you have a good one and want to keep it good, a basic overhaul, replacing the filter and having the torque converter rebuilt will see it as good as new.

[10mbc]

The 2.0 HDI C5 in the signature is already sold and it was a 5 speed manual. I am now looking to buy a C5 and this one has the 2.2 HDI 133ps and the 4HP20 automatic gearbox. I have not bought the car yet, I am doing research and I am ready to buy if the right car appears. If this would have had the 2.0 HDI 136ps + the 6 speed Aisin, I would have already bought it.

It is close to impossible to check the car in the real world unfortunately. I do have a mechanic here but I can't have him come with me and buy the car from another city. While I would really like an automatic gearbox, it seems like I would have to get a manual, just to not have this headache.

[CitroJim]

All fully understood... May you have great success in finding a good C5...

[citroenguy]

2.0HDI 109hp is always AL4 PSA/renault gearbox

All C5 mkII 2.0HDI 136/138hp has the Aisin AM6 gearbox

2.2HDI 133hp mkI and mkII is ZF 4hp20

2.2hp 173hp is Aisin AM6 also