Roof motor fast down, slow up — ideas?

[JPB]

Hi all, typical problem with roof motor but with some options already explored/ruled out.

Problem: Roof is fast to go down but slow to go up
What I'd like: Roof to go fast down and fast up, no more running around garages and me trying fixes to get it to work, I just want to get someone on it to sort it properly so I can forget about it.

Tried:
- RBM relocated roof motor to boot but fast down/slow up problem persisted. Told me it was water in the hydraulic lines.
- Took to a local independent BMW specialist who looked and recommended I try a new motor first (had been sat in water and a bit rusty).
- Fitted new motor and speed was improved but still slow compared to how it used to be.
- Independent specialist is now saying they have to take roof out to access hydraulic lines and investigate further e.g. test it all while it's out of car, refill hydraulic oil, potentially fit new motor and pump that they buy in from BMW.

Independent specialist wants £620 (inc VAT) to do the above (5-6 hours labour) and says new motor unit will be approx £300 from BMW.

Before I drop nearly £1000 to make my roof slightly faster at going up, does anyone with experience have recommendations of what to try next? I'm going to phone around garages and BMW today to get quotes to 'just fix it'.

Many thanks in advance!
Jase
(based in Gloucestershire)

 

[bigwinn]

Quickest way to further diagnose would be to swap the power and hydraulic lines around

If the roof issues stay the same- there is something amiss with your rams/hinges

However as you’ve had a new motor fitted I’d say you’d be unlucky to have the same issues with 2 motors… but I’d still try that

 

[True-Blue]

Morning,

Have you only had the bottom part of the pump replaced, I.e. the electric motor section?
The top part includes the impeller, which is likely worn.
Reversing the hydraulic hoses should provide a better solution, but not a complete fix.

If I’m right, reversing the hydraulic hoses will cause the roof to raise quickly, but open slowly. However, gravity is on your side. A gentle push whilst opening to get the roof past a certain opening point will have it opening more quickly (falling/gravity + hydraulics)

This should be a free way for it to be much more serviceable, but not perfect.

As you’re in Gloucester your ‘go to’ should be Alan Jones @Number5, has fixed many roofs - sounds like you need a new impeller section for a perfect fix though

 

[enuff_zed]

Agreed. Classic symptoms of the pump failing. Though it can also be due to the bypass plunger being very slightly pushed in. Pump has to work harder against gravity and pressure can sneak past. Definitely recommend a trip to Alan (@Number5 )

 

[JPB]

Thank you all for the responses. Correct, I have only replaced the motor, not the pump. Sounds like this might be the culprit then. Thanks for the recommendation, I will drop Alan a line!

 

[Number5]

In contact and talking

 

[JPB]

For any that come across this thread looking for answers. TLDR: The impeller section was a bit old and needed replacing.

Number5 was great and very helpful, knew his stuff! (Thanks again!). Turned out the new motor I'd bought was not compatible with the existing impeller head unit (the flange that couples into the seal needed an extra 'ridge') despite the eBay listing stating it was compatible. I'm returning for a refund. Now fully fixed and working like brand new thanks to Number5! Would recommend if you have any problems and are nearby. Do check when you're ordering your motor online! Or buy the whole unit and not just a new motor on an old impeller section.

 

[enuff_zed]

For any that come across this thread looking for answers. TLDR: The impeller section was a bit old and needed replacing.

Number5 was great and very helpful, knew his stuff! (Thanks again!). Turned out the new motor I'd bought was not compatible with the existing impeller head unit (the flange that couples into the seal needed an extra 'ridge') despite the eBay listing stating it was compatible. I'm returning for a refund. Now fully fixed and working like brand new thanks to Number5! Would recommend if you have any problems and are nearby. Do check when you're ordering your motor online! Or buy the whole unit and not just a new motor on an old impeller section.

Thought he'd soon sort that for you.
To clarify for those that may be in a similar situation; if you have the older style motor which separates from the spacer section, then you can replace the whole lot with one that has the integral spacer. This should hopefully be sealed at that join.

 

[JPB]

Thought he'd soon sort that for you.
To clarify for those that may be in a similar situation; if you have the older style motor which separates from the spacer section, then you can replace the whole lot with one that has the integral spacer. This should hopefully be sealed at that join.

Yep, this type. (New motor is shiny cylinder at bottom).