M4 comp convertible buying advice
Discussion
I bought a 2015 on 47k last year. I’d check that it doesn’t have the water drainage problem (lots of videos on you tube to show you how serious it can be)
I looked for one with a full BMW service history, hoping this would show it had been looked after. Independents are fine too of course, it’s where I go now, but with an updated idrive showing all services put my mind at rest a little.
My diff needed to be removed and serviced due to a leak , it was expensive so I’d check that if you can.
I wouldn’t want one that has been mapped.
I think you should find one with the HUD and the H&K sound upgrade. I don’t know of any major issues, cooler and turbo can cause issues but you’ll normally identify that with smoke and a drive. The crank hub comes up as a problem lots of times but without a map it should be fine.
I looked for one with a full BMW service history, hoping this would show it had been looked after. Independents are fine too of course, it’s where I go now, but with an updated idrive showing all services put my mind at rest a little.
My diff needed to be removed and serviced due to a leak , it was expensive so I’d check that if you can.
I wouldn’t want one that has been mapped.
I think you should find one with the HUD and the H&K sound upgrade. I don’t know of any major issues, cooler and turbo can cause issues but you’ll normally identify that with smoke and a drive. The crank hub comes up as a problem lots of times but without a map it should be fine.
Thanks very much.
Will look up the drainage issue, I wasn't aware of that.
I'm always a bit OCD with buying used cars, I guess having my fingers burnt in the past makes me a bit paranoid!
Funny you mention diff leaks, The recent MOT history of the car i am looking at states:
2024 : Monitor and repair if necessary (advisories):
Rear Fluid leak, but not excessive (8.4.1 (a) (i))
interestingly the MOT the year before was a fail, then a retest due to screwed tyres.
I wonder if the advisories are relevant to the current fluid leak?
Monitor and repair if necessary (advisories):
Offside Rear Drive shaft damaged but serviceable (6.1.7 (e))
Offside Rear Fluid leak, but not excessive output shaft seal leaking on differential (8.4.1 (a) (i))
Do you mind me asking how much the work was on your differential issue?
Will look up the drainage issue, I wasn't aware of that.
I'm always a bit OCD with buying used cars, I guess having my fingers burnt in the past makes me a bit paranoid!
Funny you mention diff leaks, The recent MOT history of the car i am looking at states:
2024 : Monitor and repair if necessary (advisories):
Rear Fluid leak, but not excessive (8.4.1 (a) (i))
interestingly the MOT the year before was a fail, then a retest due to screwed tyres.
I wonder if the advisories are relevant to the current fluid leak?
Monitor and repair if necessary (advisories):
Offside Rear Drive shaft damaged but serviceable (6.1.7 (e))
Offside Rear Fluid leak, but not excessive output shaft seal leaking on differential (8.4.1 (a) (i))
Do you mind me asking how much the work was on your differential issue?
I took my car to BMW for a brake fluid change and whilst it was on the ramp they recorded one of their video walk arounds. The diff obviously has 3 seals and it’s normally the rubber parts that start deteriorating after 10 years! The diff was covered in oil that was stuck to the heat sink, rather than dripping all over the floor.
Running the car with no oil in the diff will lead to over heating and drive train warnings….
I had all 3 replaced with Redish here in Bristol and together with an oil change it was almost £1900. That was for the Input seal (which required their special tools to remove the carbon drive shaft) and both output seals. Which required springs, drive shafts, sub frame and gawd knows what else ending up on the floor…..
If you were to buy the car you’ve been looking at, I would take it straight to check the oil level in the diff followed by a diff oil change
https://www.redish-motorsport.com/BMWF80M3S55DiffI...
https://www.redish-motorsport.com/BMWF80M3S55DiffO...
Other than that and a £56 brake fluid change at BMW it’s been faultless , now almost 59k miles as I use it daily and it will have its first MOT with me at the end of April.
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Running the car with no oil in the diff will lead to over heating and drive train warnings….
I had all 3 replaced with Redish here in Bristol and together with an oil change it was almost £1900. That was for the Input seal (which required their special tools to remove the carbon drive shaft) and both output seals. Which required springs, drive shafts, sub frame and gawd knows what else ending up on the floor…..
If you were to buy the car you’ve been looking at, I would take it straight to check the oil level in the diff followed by a diff oil change
https://www.redish-motorsport.com/BMWF80M3S55DiffI...
https://www.redish-motorsport.com/BMWF80M3S55DiffO...
Other than that and a £56 brake fluid change at BMW it’s been faultless , now almost 59k miles as I use it daily and it will have its first MOT with me at the end of April.
Edited by oldaudi on Thursday 3rd April 20:12
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Edited by oldaudi on Thursday 3rd April 20:15
Have you driven a convertible m4 yet, if not and you can try one it’s worth it. It’s 200kg heavier than a coupe and obviously has more ‘rattles’ due to the roof. Sounds obvious so apologies to ask but I forgot about the 200kg when thinking about one.
The tin roof is a nicer place to be than a traditional hood I think, especially poor weather etc, but it is a complex item, and needs to be maintained/serviced and might leak at some point - you just have to accept that risk.
The rear quarters can fill with water due to blocked floor pan/cill drain plugs, it’s an easy fix (remove plugs, make holes in plastic cill covers) but can be expensive damage if not caught early. Search for the issue and ‘window hall sensors’. When the latter fail due to water damage, the roof may not open, but worse may not close fully. Some also suffer from leaking C pillar rubbers, in heavy rain water drips onto the plastic ledge of the internal quarter panel trim. Some indies won’t work on the roof, luckily mine did the hall sensors as a warranty fix, it looked like previous water ingress had occurred and they failed over time. My quarters have the drain plugs removed and the extra holes in the cill covers so drain cleanly but it clearly suffered early in its life from the issue. The ‘fix’ was a bmw bulletin I think for cars under warranty. Having said all of the above, it’s likely that not all cars suffer the issues so hard to know if common or just enough to cause internet posts.
With the roof down, it’s great to drive, you forget the risk of the above, especially when the exhaust explodes at max rev gear changes. It’s a great car, I’m not trying to put you off, but go into it with the understanding that the roof is a complex moving part that needs looking after and will need servicing (cleaning rubbers, drains, lubricating of moving parts and rubbers and at some point probably a bit of ££maintenance). Tbh, same probably applies to all/any convertibles over time.
I use mine daily, it’s docile in efficient/comfort and a bit brutal in Sport+, I tend to stay in Sport mode. It returns the same mpg as my previous 640i GC. Neck scarfs are worth it so look for that option. I think comfort pack includes them and heated steering wheel. Only done 4K miles, it’s on 34k now and the sytner walk around during the obligatory air bag recall didn’t identify any issues other than front discs getting close, which I knew were within 10k miles of end of life when I bought it. It’s a 2017 Competition. The interior is a nice place to be, mine is Silverstone merino.
Having said all of the above, and having had a roof close failure due to a hall sensor which was a rectum clenched moment at the time, I’d still buy mine again so I’d say go for it.
The tin roof is a nicer place to be than a traditional hood I think, especially poor weather etc, but it is a complex item, and needs to be maintained/serviced and might leak at some point - you just have to accept that risk.
The rear quarters can fill with water due to blocked floor pan/cill drain plugs, it’s an easy fix (remove plugs, make holes in plastic cill covers) but can be expensive damage if not caught early. Search for the issue and ‘window hall sensors’. When the latter fail due to water damage, the roof may not open, but worse may not close fully. Some also suffer from leaking C pillar rubbers, in heavy rain water drips onto the plastic ledge of the internal quarter panel trim. Some indies won’t work on the roof, luckily mine did the hall sensors as a warranty fix, it looked like previous water ingress had occurred and they failed over time. My quarters have the drain plugs removed and the extra holes in the cill covers so drain cleanly but it clearly suffered early in its life from the issue. The ‘fix’ was a bmw bulletin I think for cars under warranty. Having said all of the above, it’s likely that not all cars suffer the issues so hard to know if common or just enough to cause internet posts.
With the roof down, it’s great to drive, you forget the risk of the above, especially when the exhaust explodes at max rev gear changes. It’s a great car, I’m not trying to put you off, but go into it with the understanding that the roof is a complex moving part that needs looking after and will need servicing (cleaning rubbers, drains, lubricating of moving parts and rubbers and at some point probably a bit of ££maintenance). Tbh, same probably applies to all/any convertibles over time.
I use mine daily, it’s docile in efficient/comfort and a bit brutal in Sport+, I tend to stay in Sport mode. It returns the same mpg as my previous 640i GC. Neck scarfs are worth it so look for that option. I think comfort pack includes them and heated steering wheel. Only done 4K miles, it’s on 34k now and the sytner walk around during the obligatory air bag recall didn’t identify any issues other than front discs getting close, which I knew were within 10k miles of end of life when I bought it. It’s a 2017 Competition. The interior is a nice place to be, mine is Silverstone merino.
Having said all of the above, and having had a roof close failure due to a hall sensor which was a rectum clenched moment at the time, I’d still buy mine again so I’d say go for it.
Edited by Veesix75 on Thursday 3rd April 22:25
Cheers guys.
I drove a 16 plate Comp Convertible at the weekend being sold via a dealer near me.
Fantastic fun to drive and definitely high on the list to buy.
The car had a very faint ticking tappy noise on tick over. Being paranoid i questioned it, apparently they are all abit like that according to the dealer?
I didnt notice any other issues of note, It was a cold start and had obviously been sitting for a while.
The one thing that put me off was in the glove box.
I appreciate that people have bad stuff happen in their lives but i found 2 HMP prison passes and next to it a VEEPEAK OBDCheck BLE engine management coder. Not the dealers and the car is an SOR, so alarm bells are ringing. Shame as it is lovely spec and right in my hitting zone.
Ticker over video for ref: https://youtu.be/SOe4DPWBvG4?si=IGa7rorSDWVpNv6G
I drove a 16 plate Comp Convertible at the weekend being sold via a dealer near me.
Fantastic fun to drive and definitely high on the list to buy.
The car had a very faint ticking tappy noise on tick over. Being paranoid i questioned it, apparently they are all abit like that according to the dealer?
I didnt notice any other issues of note, It was a cold start and had obviously been sitting for a while.
The one thing that put me off was in the glove box.
I appreciate that people have bad stuff happen in their lives but i found 2 HMP prison passes and next to it a VEEPEAK OBDCheck BLE engine management coder. Not the dealers and the car is an SOR, so alarm bells are ringing. Shame as it is lovely spec and right in my hitting zone.
Ticker over video for ref: https://youtu.be/SOe4DPWBvG4?si=IGa7rorSDWVpNv6G
smuudge said:
Cheers guys.
I drove a 16 plate Comp Convertible at the weekend being sold via a dealer near me.
Fantastic fun to drive and definitely high on the list to buy.
The car had a very faint ticking tappy noise on tick over. Being paranoid i questioned it, apparently they are all abit like that according to the dealer?
I didnt notice any other issues of note, It was a cold start and had obviously been sitting for a while.
The one thing that put me off was in the glove box.
I appreciate that people have bad stuff happen in their lives but i found 2 HMP prison passes and next to it a VEEPEAK OBDCheck BLE engine management coder. Not the dealers and the car is an SOR, so alarm bells are ringing. Shame as it is lovely spec and right in my hitting zone.
Ticker over video for ref: https://youtu.be/SOe4DPWBvG4?si=IGa7rorSDWVpNv6G
They are quite tappy at idle especially when cold (Mine's a 2019 non comp coupe).I drove a 16 plate Comp Convertible at the weekend being sold via a dealer near me.
Fantastic fun to drive and definitely high on the list to buy.
The car had a very faint ticking tappy noise on tick over. Being paranoid i questioned it, apparently they are all abit like that according to the dealer?
I didnt notice any other issues of note, It was a cold start and had obviously been sitting for a while.
The one thing that put me off was in the glove box.
I appreciate that people have bad stuff happen in their lives but i found 2 HMP prison passes and next to it a VEEPEAK OBDCheck BLE engine management coder. Not the dealers and the car is an SOR, so alarm bells are ringing. Shame as it is lovely spec and right in my hitting zone.
Ticker over video for ref: https://youtu.be/SOe4DPWBvG4?si=IGa7rorSDWVpNv6G
Maybe my perception of BMW is all wrong, it just sounded a bit naff for a high-performance luxury car!
I also forgot to mention, i questioned the rear leak advisory. The garage is willing to replace the 'Input Seal' to make the sale.
Apparently a 4 hour job - for some reason i thought it was a bigger job to rectify...
I also forgot to mention, i questioned the rear leak advisory. The garage is willing to replace the 'Input Seal' to make the sale.
Apparently a 4 hour job - for some reason i thought it was a bigger job to rectify...
Just bought a 2018 comp convertible from BMW. We love the car but it’s early days yet so in the honeymoon period. Keep getting a battery discharge message and the wing mirrors do not fold in or out when locking/unlocking the car. Going in at the end of the month to get it checked out. A rear fractured spring was found on the MOT and replaced so maybe worth a look over the springs if you can.
I totally get where you are coming from being paranoid, I am too after getting my fingers burnt on cars. Sadly something most of us have experienced during our car ownership journey. When we initially viewed the car it had only just arrived and had not been prepped for sale. This might sound weird but I actually liked that as it gave me a chance to see it before it was made ready for sale in its previous ownership state.
Still very early days but I’m very pleased with the purchase and the car. Hope it carries on like that.
I totally get where you are coming from being paranoid, I am too after getting my fingers burnt on cars. Sadly something most of us have experienced during our car ownership journey. When we initially viewed the car it had only just arrived and had not been prepped for sale. This might sound weird but I actually liked that as it gave me a chance to see it before it was made ready for sale in its previous ownership state.
Still very early days but I’m very pleased with the purchase and the car. Hope it carries on like that.
wolfie28 said:
Just bought a 2018 comp convertible from BMW. We love the car but it’s early days yet so in the honeymoon period. Keep getting a battery discharge message and the wing mirrors do not fold in or out when locking/unlocking the car. Going in at the end of the month to get it checked out. A rear fractured spring was found on the MOT and replaced so maybe worth a look over the springs if you can.
I don't fold mine in to be honest, but could you not hold your finger on the button longer on the key to make them fold in though? My mirrors don’t fold in on the key fob either, it’s just the button on the door switches. I thought they would fold from the fob as per the 640i.
Smuudge, I wouldn't let the hmp passes put you off, so long as the car is right and been serviced well and it’s standard. The code reader wouldn’t bother me either.
Smuudge, I wouldn't let the hmp passes put you off, so long as the car is right and been serviced well and it’s standard. The code reader wouldn’t bother me either.
Edited by Veesix75 on Tuesday 8th April 16:23
Veesix75 said:
My mirrors don’t fold in on the key fob either, it’s just the button on the door switches. I thought they would fold from the fob as per the 640i.
Smuudge, I wouldn't let the hmp passes put you off, so long as the car is right and been serviced well and it’s standard. The code reader wouldn’t bother me either.
Cheers, yes the HMP passes are a strange one. The code reader was probably my mind running wild abit. Smuudge, I wouldn't let the hmp passes put you off, so long as the car is right and been serviced well and it’s standard. The code reader wouldn’t bother me either.
Edited by Veesix75 on Tuesday 8th April 16:23
I believe that particular coder can clear Engine management warning lights amongst others... so making me wonder why and what it was used for.
Have put it to the dealer anyway, and most of my other concerns they are prepared to deal with, still waiting to hear if they will do the Airbag recall for me, which i believe is a common issue.
Had 3 air bag recalls, e46 m3, 640i and m4. It’s no big deal so long as you have a main dealer near you. I had free tea and biscuits at sytner, looked at a few cars, and left after 90 mins. Free car wash at the same time for all 3 visits.
Can the selling dealer do a code read/printout for you, and could / does it show when the last code reset was performed on the read out? I’ve had one before from the Indy I use but I can’t remember if it had any history or reset dates on it.
Can the selling dealer do a code read/printout for you, and could / does it show when the last code reset was performed on the read out? I’ve had one before from the Indy I use but I can’t remember if it had any history or reset dates on it.
Veesix75 said:
Can the selling dealer do a code read/printout for you, and could / does it show when the last code reset was performed on the read out? I’ve had one before from the Indy I use but I can’t remember if it had any history or reset dates on it.
Thanks, that’s a really good suggestion, I know they do their own code reader checks on their cars but I haven’t seen any paperwork to back it up on this vehicle. Il drop them a note and see what they have. I had a 2016 M4 conv (not comp) for 4 years and 30k miles. No problems at all, only routine servicing and tyres.
One thing I would consider, is that cars registered at some point in 2017 qualify for the lower (£190 per year) road tax. If you're in the market anyway, may be worth going for one of those.
I've had a few convertibles and this was the best all rounder. Useable all year around, very refined with the roof down - make sure though that it has the convertible convenience pack, which gives heated seats, neck scarves, heated wheel and wind deflector that fits in behind the seats. The deflectors are generally stored behind the rear seat, it folds forward to reveal the storage space. There's a big difference in the buffeting with or without the deflector.
Only downsides I would flag are in line with a few other comments. 'M' tax on parts e.g. brakes, insurance - more expensive than a 911 I replaced it with and there is some flex in the body, plus you can feel the weight. But having said all of that, I'd definitely have another as it was so useable. And the folding hard top is so much easier to look after than soft tops. Enjoy when you get one !
One thing I would consider, is that cars registered at some point in 2017 qualify for the lower (£190 per year) road tax. If you're in the market anyway, may be worth going for one of those.
I've had a few convertibles and this was the best all rounder. Useable all year around, very refined with the roof down - make sure though that it has the convertible convenience pack, which gives heated seats, neck scarves, heated wheel and wind deflector that fits in behind the seats. The deflectors are generally stored behind the rear seat, it folds forward to reveal the storage space. There's a big difference in the buffeting with or without the deflector.
Only downsides I would flag are in line with a few other comments. 'M' tax on parts e.g. brakes, insurance - more expensive than a 911 I replaced it with and there is some flex in the body, plus you can feel the weight. But having said all of that, I'd definitely have another as it was so useable. And the folding hard top is so much easier to look after than soft tops. Enjoy when you get one !
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