2007 2.2 Ti Selespeed issues

[Astroboy56]

G'day All, first post however been reading the forum for years and it's been the best source of info!!!
I purchased a 2007 159 2.2 Ti about 4 years ago and love the Alfa!!!
Being an ex mechanic I have done all my own work such as suspension, electrical and everything else however I need assistance with a selespeed issue. While driving recently the car started dropping into neutral, I stop turn it off for a few minutes and then it's OK again. However now it is starting to happen on a regular basis. The alfa has done 220k Km's and is running fine, I have changed all the fluids and removed the accumulator and it seems OK, I think it may be a hydraulic problem so I plugged in the multiscan (which I am still working out) and looking at the hydraulic pressure with the car stopped and running it only goes to 44 bar so I am thinking now it could be a pump problem? When I open the drivers door I can hear the pump prime and with the ignition on I can hear the pump kick in every second gear change so as with all the info I have seen in the posts everything seems OK.  Any assistance or ideas would be appreciated as I do not like taking my car to a mechanic ( nothing against mechanics ha ha) because I like to work on my own cars!!

[bazzbazz]

In the 159/Brera series the Selespeed hydraulic system operates between 36.5 & 46 Bar.

At 220,000 kms I would say your accumulator may not be holding pressure properly, if the system detects low pressure it drops to neutral automatically to prevent the car stalling while stuck in gear.

It could also be the Pump is worn as well, when you turn off the car and restart it, the vibration can be enough to shake the brushes loose. So I would recommend replacing both pump & accumulator together, if the budget will allow.

One other thing that gets missed is no-one EVER changes the brake fluid in the Clutch master cylinder, resulting in the feed port from the Clutch reservoir to the Master Cylinder blocking up. So while you're there, replace the fluid in the clutch Master Cylinder.

[Astroboy56]

Hi Bazz,

I have read your posts in the past and you must be a wizz with Alfa's 
Thanks for the info!!! I had a inkling that it may be due to pressure, I removed the accumulator and could only get a wire in about 35 mm which according to the posts is OK however I will check out the $$$ before I get one. I will remove the pump as I have a suspicion  that could be a contributing factor. Also I have taken your advice in the past and cleaned the clutch master cylinder and replaced the fluid on a regular basis. Thanks for the assistance! I will let you know how I go as I think I will pull the pump first.

[bazzbazz]

I have read your posts in the past and you must be a wizz with Alfa's 

You'll make me blush. 

I removed the accumulator and could only get a wire in about 35 mm which according to the posts is OK however I will check out the $$$ before I get one.

That doesn't mean it hasn't got a split in the diaphragm, or is just worn.

At 220,000 kms, you'll find that both the pump & accumulator will be a little tired. Admittedly the pump in the 159 is far superior to the type in the 156/147, and to date I personally haven't had to change one yet and have no idea as to what their life is.

Without taking the car for a diagnostic test drive and driving till it failed I couldn't tell you which of the two was the culprit.

[Astroboy56]

Thanks Baz!
I am still investigating the issue and I may have to do pump and Accumulator however being a idiot who likes to be sure I can't help but want to track it down. I have some stats below if it helps?
I did a clutch drain to make there was no air in the system. seemed to go OK with no error.
Hydraulic pressure in N ign on 38 to 39 bar OK?
change to 1ST and it's 46 bar and  from there the pump kicks in every second change and ranges between 38 to 46 bar however there were a few times it dropped to 33 bar which I presume is the low pressure point for the pump to kick in.
I am going to take it for a drive and see what errors come up!
Thanks for all the advice to as I have always had holdens through the years and I love working on this car because as they say it always good to learn new things!!
Thanks for sharing!!!

Regards Astroboy!

[Astroboy56]

Good evening all,

Just wondering if anyone can answer a question please?

When you measure the selespeed hydraulic pressure (bar) with the multiscan, Ign on, changing up and down through the gears how should it react?
Should the pressure change slowly or  should it change quickly when changing through the gears?
Regards Astro

[Astroboy56]

G'day all,

I finally took the car for a spin after clearing the error codes and drove it until the "check gearbox light came on" checked the  error code and it's P0904 which I believe is a selection sensor error which is part no 6000100088. Is there anything else that can cause this or should I just go ahead a replace the sensor?

Regards Astro

[bazzbazz]

Just replace the sensor, it is not uncommon for them to fail.

They are a pain to fit correctly, so while you are there, if you can afford to, replace both the lower two sensors. (6000100088)

You can read here for supplemental info -

https://www.alfaowner.com/threads/have-gearbox-checked-and-gear-engagement-sensor.359606/page-2

Just don't listen to what root.anton says about using different/cheaper sensors, he doesn't know what he's is talking about.

[Astroboy56]

Hi Baz,
Good to hear from you!
Thanks for the info and the thread, I have ordered 2 and should have fun fitting them!
I will let you know how I go!
Thanks again!
Regards Astro

[Astroboy56]

G'day All,
The sensor arrived and yes BASS it was a pain to fit and thanks for the tip on pre winding it as you put it on!
It took a while and I had to buy a T20 Torx T handle driver to get the inner screw out as I didn't want to remove the pipe !
I went for a spin for an hour and drove in manual and auto and so far so good!
Thanks very much for the assistance, I have a bit more work to do however it is just standard service, oil, plugs etc.
Regards Astro!