VAQ Diff Oil Service

[EB2019]

Hi

Going to do this next weekend and got the parts needed.

But now I'm thinking...

Do I need to pull the pump to check the filter?  Most of the cars I see are rear Golf R pumps which look clogged, but has anyone checked the filter on a GTi and notice much to make me bother?

My brain is telling me I won't sleep unless I pull the pump and check it myself, but I've not seen any GTi front Diff pumps looking bad at all.

Talk me out of taking something else apart I really don't need to please

[symonh2000]

I am not going to tell you not to clean the filter.

But, I checked the filter on our car when I did the oil and it was perfectly clean. The oil also looked clean.

Mileage just over 50k with no record of a change...

[davo245]

I had my GTi performance 7.5 from new till 79k not one dealer ever said anabout diff oil change to me not even sure what the intervals are?

Never had any issues with car other than thermostat housing.

[EB2019]

I had my GTi performance 7.5 from new till 79k not one dealer ever said anabout diff oil change to me not even sure what the intervals are?

Never had any issues with car other than thermostat housing.

I think its 3 year intervals? mine was done 2 years ago by VW dealer when I bought it.

I am not going to tell you not to clean the filter.

But, I checked the filter on our car when I did the oil and it was perfectly clean. The oil also looked clean.

Mileage just over 50k with no record of a change...

Yeah I understand, but like your example I've not seen horror stories of VAQ filter clogging, only the rear golf R version of the pump, perhaps the VAQ on the front has only marginal use in most applications but the Golf r rear doesn't?

I might just switch the oil and leave it at that.

[madstaff]

Loads of info on this thread - https://www.golfgtiforum.co.uk/index.php?topic=288457.0

I have cleaned haldex pumps on a few Golf Rs when changing the oil and the filters always look filthy, i have ever only done 1 VAQ haldex diff pump, on my own CS40, and it was super clean.

I think the rear diff in an R must work alot harder than a FWD VAQ pump to create so much debris.

I think whilst you've dropped the oil out you may as well remove the pump and clean the filter, or you would always be thinking if it was clean or not??

Clogged filters make the pump run harder which is why they fail due to burning out.

[Adam T7]

Clean filter = no worries.

[EB2019]

Thanks for the replies

Sod it I will get the 2 seals for the pump

When you remove the pump you lose some oil;The pump when removed loses some oil, therefore you will be required to undertake the pump relearn process using your diagnostic tool. This will prime the pump and therefore allow the evacuated space to be filled with fresh oil.

I assume you need to top up again once this is done?

[madstaff]

This is how i did mine if i remember correctly.

First check too see if you can get the fill bung undone.

Remove drain plug and remove oil and then pump, 2 x 10mm bolts, clean filter, I took mine off but be super careful as the filters aren't available separately.

Replace o rings on the pump if you want, I didn't nor did Paul70 iirc, there about £20 from VW.

Clean round where the pump fits in the diff housing.

Smear a bit off diff oil on the o rings and fit the pump back.

Refit drain plug and fill until oil drips out of fill plug, nip up plug, then run the pump relearn with VCDS, run up for a couple of mins, temp of diff oil has to reach a specific temp I can't remember off hand, before checking.

Remove fill plug and top up if needed just until oil just seeps out..

Stand back, light your pipe and admire your handywork.

If the pump filter is clean a relearn is not strictly necessary, but if its dirty and made up I would do a relearn.
The pump measures the current required needed to reach max pressure and this will be much more if the pump is blocked.

[EB2019]

Thanks MS



Happy with all that, I ordered the 2 O-rings at £30 from VW!! , I saved on the oil and bought the BorgWarner oil through work so at least that compensates. Once this is done it won't be done for another few years so don't want old seals letting me down at some point (my car is now 5 years old so think this is the year to crack on with going over things, like this and gearbox oil change)

1 question:  if the relearn process needs to be at 20c+ to prime the pump and top up, and you are doing this in a workshop. How do you get the temp up without driving it with a low level, just run the engine for radiated heat and check on Vag-com before starting the relearn?

i.e. when filling it back up after the pump check and clean, you pour in fresh cold-ish oil into a cooled down unit, then the relearn process will be started when cold and not at 20c? and I guess you don't want to drive it as its low on oil?

[madstaff]

The fluid unless it's cold where you keep it won't be far off 20 degrees when you refill.

Temp is unimportant when relearning as all your doing is resetting the parameters so it knows, for example, 0.5Amps supplied to the pump produces 1 bar of pressure,

The temp measurement is only because the fluid expands when warm, so really needs to be checked then.

I did mine with the front wheels in the air, and just let the engine idle for a couple of mins, doesn't take long to warm up and only had to add about 50ml when checked.