e39 M5 - what to look for
Discussion
I ran one for a few years so here are a few quick issues that they can suffer from:
Sticky front brake calipers...very obvious on a test drive
Old Thermostat...causing the car to run cooler than it should..increased fuel use, not the most frugal car in the first place obviously!
Water pump leaks
Rust around fuel filler aperture, above number plate on bootlid, bootlid in general and rear slam panel
Front thrust arm bushes wear giving spongy feel and shimmy.
Jerky throttle..can be lessened by software update, sometimes made worse by Sport button, esp at low speeds
less than perfect damping now that these cars are getting on a bit unless they have been refreshed
MAF's...well documented by can cause loss of performance..easy check in the 'secret computer' on the dash...google reveals all.
02 sensors amongst other sensors setting off engine check light.
Cracked exhaust around 02 sensor's bung
some cars have suffered with Big end issues and timing chain problems..again..well documented
Vanos...as above..there are two units, one for each bank.
Oil usage on pre facelift cars...having said that I have seen pre ones that dont and post ones that do.
M5 board is a great source of info with some very knowledgable guys on there.
Just a quick list but in summary, a great car that seemingly does everything..go in with your eyes open and expect to have to dig deep at some point and the cars are hard to beat.
I loved every minute with mine.
Mark
Sticky front brake calipers...very obvious on a test drive
Old Thermostat...causing the car to run cooler than it should..increased fuel use, not the most frugal car in the first place obviously!
Water pump leaks
Rust around fuel filler aperture, above number plate on bootlid, bootlid in general and rear slam panel
Front thrust arm bushes wear giving spongy feel and shimmy.
Jerky throttle..can be lessened by software update, sometimes made worse by Sport button, esp at low speeds
less than perfect damping now that these cars are getting on a bit unless they have been refreshed
MAF's...well documented by can cause loss of performance..easy check in the 'secret computer' on the dash...google reveals all.
02 sensors amongst other sensors setting off engine check light.
Cracked exhaust around 02 sensor's bung
some cars have suffered with Big end issues and timing chain problems..again..well documented
Vanos...as above..there are two units, one for each bank.
Oil usage on pre facelift cars...having said that I have seen pre ones that dont and post ones that do.
M5 board is a great source of info with some very knowledgable guys on there.
Just a quick list but in summary, a great car that seemingly does everything..go in with your eyes open and expect to have to dig deep at some point and the cars are hard to beat.
I loved every minute with mine.
Mark
If driven hard the e39 M5 will eat clutches, so make sure that has been done. You are looking at £600 for a clutch fitted more if it needs a new flywheel.
Don’t be alarmed with early high mileage cars having noisy vanos there is a lot of hype regarding vanos issues which are not always valid. I have had 6 M cars and never had a vanos issue. Driven/serviced correctly you will rarely run into trouble.
They also use a bit of oil so don’t be alarmed its normal. Especially on the older cars which don’t have the revised engine (new piston rings).
Sills, Arch rust and rust on the boot lid are common.
Wear in the inside of the rear tyres.
The old Radio unit "BM24" in the boot suffer from dry solder joints, this results in sound lost. GCSE level soldering can fix this, Easy 30 minute job.
Thrust bearings as mentioned, a good upgrade is to use X5 bushes as they are a little stronger.
Awesome Car
Don’t be alarmed with early high mileage cars having noisy vanos there is a lot of hype regarding vanos issues which are not always valid. I have had 6 M cars and never had a vanos issue. Driven/serviced correctly you will rarely run into trouble.
They also use a bit of oil so don’t be alarmed its normal. Especially on the older cars which don’t have the revised engine (new piston rings).
Sills, Arch rust and rust on the boot lid are common.
Wear in the inside of the rear tyres.
The old Radio unit "BM24" in the boot suffer from dry solder joints, this results in sound lost. GCSE level soldering can fix this, Easy 30 minute job.
Thrust bearings as mentioned, a good upgrade is to use X5 bushes as they are a little stronger.
Awesome Car
It's strange about the clutch ware.
Mine was on 84k when I bought it now on 132k
I have not replaced it and as far as I am aware I don't think it has ever had one. I've done a few track days and don't drive it easy, however I don't go in for rapid getaways.
Mine was on 84k when I bought it now on 132k
I have not replaced it and as far as I am aware I don't think it has ever had one. I've done a few track days and don't drive it easy, however I don't go in for rapid getaways.
Edited by scarecrow on Thursday 13th February 21:18
Edited by scarecrow on Thursday 13th February 21:18
It's strange about the clutch ware.
Mine was on 84k when I bought it now on 132k
I have not replaced it and as far as I am aware I don't think it has ever had one. I've done a few track days and don't drive it easy, however I don't go in for rapid getaways.
Mine was on 84k when I bought it now on 132k
I have not replaced it and as far as I am aware I don't think it has ever had one. I've done a few track days and don't drive it easy, however I don't go in for rapid getaways.
Edited by scarecrow on Thursday 13th February 21:18
Edited by scarecrow on Thursday 13th February 21:19
Standing starts and poor clutch control eat M5 clutches, treated well they should easily last 100k. I've heard of some lasting over 200k.
The viscous fan clutch is another possible weak point. They usually fail by locking up. With the engine cold, test the fan with a rolled up news paper, you should be able to stop it easily. If they lock up the fan can explode at high engine revs, taking out the radiator, hoses, bonnet and if you're unlucky the engine wiring loom.
Battery drain can be a problem too, common culprits are the fan control resistor pack (hedgehog), Traffic Master system and the older wired car phones.
With a little common sense and a few regular checks they should be very reliable.
The viscous fan clutch is another possible weak point. They usually fail by locking up. With the engine cold, test the fan with a rolled up news paper, you should be able to stop it easily. If they lock up the fan can explode at high engine revs, taking out the radiator, hoses, bonnet and if you're unlucky the engine wiring loom.
Battery drain can be a problem too, common culprits are the fan control resistor pack (hedgehog), Traffic Master system and the older wired car phones.
With a little common sense and a few regular checks they should be very reliable.
I'll add the following-
Leaking power steering hoses
Weeping diff seals
Leaking door vapour barriers (rear mainly)
Dead pixels on the radio/instrument cluster
Soft oil separator hoses
Oil filter mounts (mind-bogglingly expensive for that they are, BMW obviously caught onto these failing)
With regards to rust, check around the jacking pads as well as the general bodywork.
Leaking power steering hoses
Weeping diff seals
Leaking door vapour barriers (rear mainly)
Dead pixels on the radio/instrument cluster
Soft oil separator hoses
Oil filter mounts (mind-bogglingly expensive for that they are, BMW obviously caught onto these failing)
With regards to rust, check around the jacking pads as well as the general bodywork.
Edited by Patrick Bateman on Thursday 13th February 20:06
RichardM5 said:
Battery drain can be a problem too, common culprits are the fan control resistor pack (hedgehog), Traffic Master system and the older wired car phones.
I've got a 540 and this just happened to me last night, whole car is dead. I bought a new battery at the end of 2011 and all was working fine on Tuesday night when I last used it. I have the above 'options', not that they are very useful in 2014!Going to get a jump on Saturday morning so if it starts then it can't be catastrophic electrical failure caused by the recent heavy rain. I'll probably end up buying a new battery but how does one go about checking where the battery drain is coming from?
nick1275 said:
In Double glazed cars the glass can delaminate and is a very expensive fix
It's only the protection double glazing that fails, the regular double glazing is fine. The protection glass is exceedingly expensive and made to order, can take months.There is a difference in the shape of the black strip around the double glazed units. The standard double glazing has square corners on the top of the front window near the B pillar
The protection double glazing has rounded corners and de-laminates like this
Checking for battery drain can be a very time consuming task on these cars.
You need to measure the current on the negative battery terminal, you'll need a meter that has a very large range, 20A to 10mA. Drain should be less than 10mA ideally.
You need to pull the fuses for different devices one by one, BUT you must leave the car to enter sleep mode for 15-20 minutes after pulling each one to make sure! Every time you open a door or lock/unlock the car it will wake up, so you need to have the car in a location where you can leave the boot open for long periods of time. You also need to have a battery charger connected at all times except when measuring the drain, otherwise you'll flatten the battery even without any fault.
In addition, if your battery has been totally flattened just once, it will have significantly reduced capacity. If it's been flattened several times it's probably scrap. So try to get to the bottom of the problem BEFORE replacing the battery.
You can also get faults that are intermittent, these are the most difficult to find but are usually on non critical systems, Phone, Nav, Radio, Amp etc. You may need to test them for current draw quite a few times before they show the fault.
The entire process can take weeks if you are unlucky, but with some targeted testing on known potential faults you can often do it in a few hours.
You need to measure the current on the negative battery terminal, you'll need a meter that has a very large range, 20A to 10mA. Drain should be less than 10mA ideally.
You need to pull the fuses for different devices one by one, BUT you must leave the car to enter sleep mode for 15-20 minutes after pulling each one to make sure! Every time you open a door or lock/unlock the car it will wake up, so you need to have the car in a location where you can leave the boot open for long periods of time. You also need to have a battery charger connected at all times except when measuring the drain, otherwise you'll flatten the battery even without any fault.
In addition, if your battery has been totally flattened just once, it will have significantly reduced capacity. If it's been flattened several times it's probably scrap. So try to get to the bottom of the problem BEFORE replacing the battery.
You can also get faults that are intermittent, these are the most difficult to find but are usually on non critical systems, Phone, Nav, Radio, Amp etc. You may need to test them for current draw quite a few times before they show the fault.
The entire process can take weeks if you are unlucky, but with some targeted testing on known potential faults you can often do it in a few hours.
I work on the technical side of the fenestration industry and yet struggle to understand any benefit of the double glazing on the M5.
As far as I M aware it is only the side windows so any marginal benefit from the double panes is negated by the windscreen and rear window being none double glazed. Imagine having two windows in the front of your living room and one is double glazed and the other isn't.
The air gap between the panes is so small that any acoustic or thermal benefit would be negligible.
There is the extra weight to lug around, glass wheighs 2.5kg per mm per square metre.
Due to their nature they will inevitably breakdown resulting in the need for expensive replacement.
As far as I M aware it is only the side windows so any marginal benefit from the double panes is negated by the windscreen and rear window being none double glazed. Imagine having two windows in the front of your living room and one is double glazed and the other isn't.
The air gap between the panes is so small that any acoustic or thermal benefit would be negligible.
There is the extra weight to lug around, glass wheighs 2.5kg per mm per square metre.
Due to their nature they will inevitably breakdown resulting in the need for expensive replacement.
RichardM5 said:
Checking for battery drain can be a very time consuming task on these cars.
You need to measure the current on the negative battery terminal, you'll need a meter that has a very large range, 20A to 10mA. Drain should be less than 10mA ideally.
You need to pull the fuses for different devices one by one, BUT you must leave the car to enter sleep mode for 15-20 minutes after pulling each one to make sure! Every time you open a door or lock/unlock the car it will wake up, so you need to have the car in a location where you can leave the boot open for long periods of time. You also need to have a battery charger connected at all times except when measuring the drain, otherwise you'll flatten the battery even without any fault.
In addition, if your battery has been totally flattened just once, it will have significantly reduced capacity. If it's been flattened several times it's probably scrap. So try to get to the bottom of the problem BEFORE replacing the battery.
You can also get faults that are intermittent, these are the most difficult to find but are usually on non critical systems, Phone, Nav, Radio, Amp etc. You may need to test them for current draw quite a few times before they show the fault.
The entire process can take weeks if you are unlucky, but with some targeted testing on known potential faults you can often do it in a few hours.
Thanks mate. JoyYou need to measure the current on the negative battery terminal, you'll need a meter that has a very large range, 20A to 10mA. Drain should be less than 10mA ideally.
You need to pull the fuses for different devices one by one, BUT you must leave the car to enter sleep mode for 15-20 minutes after pulling each one to make sure! Every time you open a door or lock/unlock the car it will wake up, so you need to have the car in a location where you can leave the boot open for long periods of time. You also need to have a battery charger connected at all times except when measuring the drain, otherwise you'll flatten the battery even without any fault.
In addition, if your battery has been totally flattened just once, it will have significantly reduced capacity. If it's been flattened several times it's probably scrap. So try to get to the bottom of the problem BEFORE replacing the battery.
You can also get faults that are intermittent, these are the most difficult to find but are usually on non critical systems, Phone, Nav, Radio, Amp etc. You may need to test them for current draw quite a few times before they show the fault.
The entire process can take weeks if you are unlucky, but with some targeted testing on known potential faults you can often do it in a few hours.
Edit: I reckon I know what's happened. Wind has made car alarm go off in the day and it's run itself down. I noticed the alarm going off last week when it was very windy and heard a number of cars bleeping on our street tonight.
How long would I need to drive to charge it back up and/or is it worth just buying a new battery?
OP, apologies for major off topic
Edited by The Stiglet on Friday 14th February 21:46
The Stiglet said:
Thanks mate. Joy
Edit: I reckon I know what's happened. Wind has made car alarm go off in the day and it's run itself down. I noticed the alarm going off last week when it was very windy and heard a number of cars bleeping on our street tonight.
How long would I need to drive to charge it back up and/or is it worth just buying a new battery?
OP, apologies for major off topic
I've only skim read this thread but be aware the bonnet switches are notorious for setting the alarms off on E39s. Disconnecting it is the easy way to stop it!Edit: I reckon I know what's happened. Wind has made car alarm go off in the day and it's run itself down. I noticed the alarm going off last week when it was very windy and heard a number of cars bleeping on our street tonight.
How long would I need to drive to charge it back up and/or is it worth just buying a new battery?
OP, apologies for major off topic
Edited by The Stiglet on Friday 14th February 21:46
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