Failed Hydro Unit

[estoril M]

Hi guys

I've recently bought an E92 325 diesel M sport and after after 3 weeks of owning the car, the driving stability lights have lit up (in yellow) on the dash board. I think I am looking at a failed hydro unit.

After speaking to two different BMW specialists, one has said that the unit is the same price for all engine ranges (4/6 cylinder) however the other has said that the 6 cylinder costs twice as much??

Has anyone had this issue before and if so what sort of price am I looking at to get it repaired?

And where do you think I would stand with standard warranty as I have only owned the car for 3 weeks?

Any help would be greatly appreciated, thanks.

[miniman]

Which specific lights are on? Could be nothing more than a wheel sensor. I'd certainly expect it to be fixed under warranty to be honest.

[estoril M]

Suspension, traction control, ABS and handbrake lights.

I was hoping it would be something as simple as this, however after quickly showing the lights to a couple of BMW specialists I've been told it is more than likely a failed hydro unit, however I've not yet had a diagnostic check to confirm this.

[miniman]

If it is the pump, worth checking with BBA Reman to see if they can help - but the dealer should put it right IMHO.

[stevesuk]

The hydro unit fault was (is) very common on E9x 3 series and 1 series of a certain age. Its usually a pressure sensor inside the unit.

We had it fail on our old 120D, and it cost us well north of £1000 to get it fixed! It was only a few months outside of warranty, but because we'd taken it to an independent to carry out an oil service and some other work, BMW weren't interested...

However, since then, BMW have introduced a repair kit, see here:

http://www.bimmerforums.co.uk/forum/f85/failed-dsc...

Which is a far cheaper option (£150 for the kit, plus whatever labour charge there is to fit it).

Might be worth checking your BMW specialists are aware of this - assuming that is where the fault is? The thread I linked to above suggests a specific fault code.

[estoril M]

is there one repair kit for all engine ranges or 1 for the 4 cylinder and 1 for the 6 cylinders???

[E30M3SE]

Repair kit, control unit DSC

34 50 6 777 163 '07, March — '07, September

applications

320d (N47)
323i (N52N)
325d (M57N2)
330d (M57N2)
330i (N52N)
335d (M57N2)
335i (N54)

34 51 6 777 165 '06, September — '07, December

applications

320d (N47)
320i (N43)
323i (N52N)
325d (M57N2)
325i (N52N)
325i (N53)
328i (N52N)
328i (N51)
330d (M57N2)
330i (N52N)
330i (N53)
335d (M57N2)
335i (N54)


34 50 6 784 812 '06, September — '08, September

applications

320d (N47)
320i (N43)
323i (N52N)
325d (M57N2)
325i (N52N)
325i (N53)
328i (N52N)
328i (N51)
330d (M57N2)
330i (N52N)
330i (N53)
335d (M57N2)
335i (N54)

[estoril M]

thanx for that I dont mean to sound daft but hear goes... I assume the codes in brackets are the engine models so if I am correct there is just one unit to suit all engine models dependant on the year of the car?? thanx again

[E30M3SE]

Yes, engine codes are in brackets.

[estoril M]

does anyone know where the hydro unit is in the engine bay to try and see if there is anything obvious to look for as in a lose lead??

[E30M3SE]

Here's a DIY hydro unit change on a LHD car.

On A RHD car it's on the opposite side.

[estoril M]

I have just looked at the unit thanx to the site you have showed me and found it. the code on the unit which is on the car now is 3452 677606 which isnt mentioned in tje codes above . is there anything obvious to look for other than a lose connection as everything seemed to be ok ? thanx again

[izabar]

how olds the car BMW just changed mine goodwill on a almost 5 year old car with no warranty just paid diagnostics and labour

[estoril M]

the car is a e92 325 d m sport on an 07 plate with 78k miles on the clock. it has full dealer service history and i have only owned the car 3 weeks so not sure where i stand with standard warranty etc... to say im unhappy is an understatment!!

[E30M3SE]

The number I've listed above are the part# for the repair kits, not the numbers of the units themselves.

If you bought the car 3 weeks ago, from a dealer I'd be having words with him in the first instance.

If this fails then a goodwill claim from BMW maybe a course of action to pursue.

Your local BMW parts dept will be able to supply you with the correct repair kit if you give them the last 7 digits of your chassis number.

[estoril M]

I have spoken to a Bmw dealers this morning and they have told me there is no repair kit for the 6 cylinder engines which means replacing the whole unit with a new one!

[izabar]

£2000 just for the part then or buy a warranty and claim in 3 or 4 months

[philmots]

estoril M said:

I have spoken to a Bmw dealers this morning and they have told me there is no repair kit for the 6 cylinder engines which means replacing the whole unit with a new one!

Sound strange.

The list above shows it for the 6 cylinder cars.

I don't see why the system would be any different.

[estoril M]

i dont understand it myself but according to bmw there is no repair kit for the 6 cylinders... i might have to think about the warranty idea if I have no joy in persuing the "goodwill gesture " from bmw

[stevesuk]

estoril M said:

i dont understand it myself but according to bmw there is no repair kit for the 6 cylinders... i might have to think about the warranty idea if I have no joy in persuing the "goodwill gesture " from bmw

Seems unbelievable that they'd offer a repair kit for one model, but not another (you'd assume they'd all use the same hydro pump). But perhaps the 6 cylinder models are fitted with a different type of pump?

Have you tried posting for advice on one of the specialist BMW forums?

Edited to add: have you had the codes read, and did they definitely suggest the hydro unit is at fault?

Edited by stevesuk on Monday 28th January 21:23