New to e85, have some questions

[OneFastMac]

I recently purchased a 2004 3.0i with a manual transmission and its in pretty decent shape for 107,000 miles
I've been reading up on issues and solutions but I see so many of the posts are old and photos are no longer linked which makes me a bit more apprehensive about getting too deep into working on the car myself. Rather than making a bunch of posts for individual concerns, I'm going to share my current list of worries for anyone to comment their experience on. I appreciate any kind of feedback you might have for me!

The power top has stopped working, after reading around I believe the main motor is partially to blame along with the passenger side seals. There were some great write-ups on how to relocate the motor and replace all the bits without needing to remove the top, so I'm grateful to have found those at least! Any other tips from experienced owners on repairing the top?

I was also able to find some diagrams to help me understand the audio system wiring as my car has a very poorly installed aftermarket amplifier and radio. The subwoofers in the car have been replaced by aftermarket brand speakers, some reading around it seemed like the OEM subwoofers were specific to the stock amplifier. Do I need to have the OEM subwoofers to make an OEM amplifier work? The goal is to get the audio back to 'stock' or as close as possible. I've also read that were I to reinstall an OEM radio unit, it would need to be programmed into the car? I haven't found info on how to do this. Not entirely sure what the OEM load out was, this car has 10 speakers, without navigation. The OEM amp and OEM radio are gone.

I have no experience with BMWs at all prior to this, the engine seems to run strong but I am the 7th reported owner of this vehicle and the only regular service records are dated back to the late 00's. Is it safe to run a fuel system cleaner on these engines? Is it safe to use standard MAF cleaner? I've read that there is an ICV separate from the MAF that also needs to be cleaned occasionally, is there a preferred way to maintain this hardware?

I have also read some info about the DISA system being a potential disaster and tell-tale signs being a rattle at lower RPMs. I believe this car has that rattle, but the EML currently shows no error codes. Is it best to clean the DISA, Replace it, or repair it with a no-fail kit?

I have also noticed a rather unnerving "clattering" sound when shutting off the engine. I read that this has to do with the clutch and if I shut the engine off while I have the clutch pedal depressed, the sound goes away. I did not see where a solution was posted; is this a sign of a bad clutch? I only have the clutch in my ford focus to compare to and it really feels about the same as far as pedal travel and engagement is concerned. How will I know if I need to replace the clutch?

 

[Smartbear]

Hi, what conditions do you see when attempting to operate the roof?

Rob

 

[Zedebee]

Great guide Smartbear, I’ve not seen that before. And for the hi-Fi, it would be helpful to know if your car was specified with the DSP “top hi-Fi” which isn’t compatible with anything, or the 10-speaker “professional hi-Fi” which is easier to swap components.

If it’s running ok, you won’t need a fuel cleaner. The intake/MAF and DISA are easy to take out, inspect and clean before you consider replacing. If there is no mayo under the oil filler cap, then your PCV is likely to be OK. If the engine is not performing as you would expect at the bottom or top end, then a VANoS refurb may be in order. Look out for leaks from the coolant header tank and check the condition of your auxiliary belts. Check for oil leaks, v.common especially around the oil pump housing, mucky but rarely terminal. Otherwise these engines are pretty robust - 107,000 miles is nothing. Your suspension will probably be knackered though :roll:

 

[OneFastMac]

Your suspension will probably be knackered though :roll:

Good info, and yes! The suspension is pretty rough, though not nearly as rough as a couple of the other similar mileage Z4s I tested before this one. At this age, I have to assume that the rear springs have been replaced. I have not had a chance to get the car on a lift to really inspect the suspension. We've just had our first cold snap of the year and salt-trucks have already been out treating roads so the car will mostly stay in for the next couple of months.
As for the sound system, I really don't know what it was originally equipped with. It is a 10 speaker system, but as to what version I do not know. The current setup is hacked into the wiring for the original amp and I haven't taken apart the dash to see how the radio was installed. My guess is it won't be good news. I tried using the sound system as it was installed because it is bluetooth capable and only the right-channel audio plays BUT it plays through all the speakers (or so it seems, I'm not even entirely sure that all 10 speakers are wired in)

Hi, what conditions do you see when attempting to operate the roof?

Initially when I got the car, the roof worked correctly, albeit slowly. The operation got slower and slower and then the last time I lowered it, the passenger side was lagging behind the drivers side. Once that went down it would not go back up. AFAIK, the motor still made noise while the top wasn't moving, but I cannot guarantee that the motor isn't somehow faulty. The passenger side carpet feels greasy and the interior of the car smells "oily" not in a motor oil sense but most likely from hydraulic fluid leaking from the passenger side. The powered latches work fine.


The car is definitely got some electrical gremlins to sort out, but I was able to get it at a very good price so I won't complain too much! All the most critical bits seems to be in good shape, I've been able to drive and enjoy the car for the last few weeks, despite the roof and audio issues.

 

[Z4Mariner]

Welcome to Z4 ownership, OneFastMac. I'm a new Z4 owner as of this past June, and yes my coupe is hibernating until Spring as well.

As far as 107K miles on your engine and transmission, unless it's had extraordinary abuse I think you'll be able to get many fun miles out of it. I bought a 2005 325xi with 83K miles, which I drove for another 130K before selling it to someone who's still driving it. The M54 engine is still fine, and the clutch didn't need replacing until 149K - even though two teens learned to drive MT on the car before I bought it. It did get new DISA, MAF, and PCV while I owned it. The rear springs are easy to inspect with wheels removed, and spring replacement is not too hard. I hope storing my Z4 winters will keep it from going through rear springs like my 325xi did (I replaced four).