DISA Faulty Symptoms / Rebuild???

[Jsomerville]

I know there is loads of info out there on DISA's but there seems to be some conflicting opinions!

FIRSTLY: How do you diagnose a faulty DISA? What are the main symptoms to look out for?

SECONDLY: What seems to be the consensus on rebuild Vs new?

- Apparently kits like the X8R solve the pin issue. Do you have to buy the X8R or are the cheaper aluminium kits just as good?
Also does the aluminium flap have any issues for being too heavy?

- Is it worth going for a whole new unit? You can pick up new non OEM ones for only £35, is there any issues with this?

Thanks in advance!!!

 

[Old-Duckman]

If you read my post in the "Check your DISA valve" thread you know my story.

Briefly from what I read about DISAs, there can be a rattling noise...not sure what other signs, I don't recall but there is plenty info out there on that if you do a search on the NET. My biggest concern were the stories where the DISA would come apart and send hard parts into your cylinders basically destroying the engine. So I decided to rebuild mine at about 54K miles.

Regarding rebuilding I read up on that on this site which also sells a kit. Here is a link to the kit I purchased which also includes a 1.2 BAR rad. cap.
https://germanautosolutions.com/store/m54-30l-disa-coolant-cap-combo/

My DISA was an aftermarket part "Viaco" brand if I recall correctly. It is not rebuild-able with the German Auto Solutions (GAS) kit so I ended up buying a BMW DISA and will save the rebuild kit for later. The owner of GAS told me the Viaco DISA was sub par quality, thus my decision to go with the stock part and I know that the BMW one is up-gradable/rebuild-able.

 

[kis]

I've had a broken flap, couldn't tell. No warning lights etc.
When I replaced it for a working one, again I couldn't tell, but obviously it was better than the busted one.

Later I did an i6 automotive mod. This is the same as X8R but they were around before. From what I've read the pins can come loose and "fall into the engine" so wanted it done asap. Later I learned that the disa buts up against something in the engine, so the pin can only fall out when you're trying to remove it. This is because the pin will gain enough clearance to fall out of the disa. So be careful when checking the disa.

Well worth doing the mod, as it ensures correct flap operation. I didn't notice any difference as mentioned before, but certainly things weren't running optimal, and well that's where you want everything really.

 

[Jsomerville]

Thanks for the feedback guys!

Based on my reading I bought the X8R kit. It's made very well, although the £70 is slightly eyewatering for what you get.

Just fitted it this evening, wow what a difference, the rattle sound I had previously has gone and on a quick drive the car definitely seems to pull much better from low down. I did the Vanos rebuild last week as well which made a difference but coupled with the DISA refurb it has transformed the feel of the engine.

I would highly recommend the XR8 DISA + Vanos rebuilds to anyone!

 

[Old-Duckman]

Thanks for the feedback guys!

Based on my reading I bought the X8R kit. It's made very well, although the £70 is slightly eyewatering for what you get.

Just fitted it this evening, wow what a difference, the rattle sound I had previously has gone and on a quick drive the car definitely seems to pull much better from low down. I did the Vanos rebuild last week as well which made a difference but coupled with the DISA refurb it has transformed the feel of the engine.

I would highly recommend the XR8 DISA + Vanos rebuilds to anyone!

Good to hear a positive feedback.
How many miles on your car ?
How difficult was the VANOS rebuild ? Did you jack the engine up or lever the support (or whatever it is called) out of the way to get the unit out? How long did it take, start to finish ?

Glad you are happy with the results.

 

[Jsomerville]

My car has done 135k so was definitely in need of it. When I pulled out the unit you could tell the seals were shot as the intake and exhaust seals were super loose inside. Literally can't stop smiling every time I drive it now, so much better cruising around in 3rd & 4th as it actually pulls now from 2-4k revs.

I wouldn't call it an easy job as there are fiddly parts to it, no engine jacking is needed though, it took 2 of us about 5 hours in total as we got stuck at quite a few points. Check out the protocols on the forum here of how to do it / videos on youtube of it done on the e46 engine. The key points to note that aren't mentioned though are:

1) The M54 engine on the e85 is set much closer to the front and access is very limited. Everything went fine until trying to remove the left plastic cap in front of the nut that holds the VANOS unit to the engine. You need some 90-degree plyers to fit in to remove it. We spent an hour cutting some plyers down and by a miracle, it came out but I wouldn't recommend it.

2) The next problem that isn't mentioned is the coolant hose and sensor the blocks the unit from coming off, it is so close but it just doesn't fit past it. You need to remove the clip from the hose and remove it while someone pulls the unit off. Coolant will piss everywhere so grab a towel and just pull it off quickly to get the Vanos unit past it, then bung it back on, same again putting it back on.

3) Now you are nearly there the unit is still stuck, get someone with a long pole / bar to leaver where the waterpump is and the couple of mm that it delivers will be just enough to pull it out. I used this tip here for the bar technique: https://z4-forum.com/forum/viewtopic.php?p=1612166#p1612166

I just did the seals which was the £79.99 kit from XR8. They do a full rebuild rattle kit as well for £140 but I couldn't justify the extra money, the seals cause 99% of the problem. With the extra change, I bought their DISA kit as well.