2010 35i sudden loss of power, code 5A53
- Thread starter enzed4
- Start date
The gearbox will naturally slip less when sport is active and also increases line pressure so you get more clamping force on the clutches, the revs are also higher which puts less strain on the transmission. The worst-case scenario for the DCT is when changing down multiple gears in normal mode. If you're in 7th gear and mash the pedal so it skips down to 3rd then this is a perfect storm that will highlight any weakness.
It's not normally a problem as the DCT is a really rugged box. The only times I've seen people have problems is on cars with large upgraded turbos and cars that have low transmission fluid in the gearbox.
I wouldn't try and do it again. Once the clutches start slipping they can wreck themselves fairly quickly. Best to just get the filters and fluid changed along with fixing any leaks.
It's not normally a problem as the DCT is a really rugged box. The only times I've seen people have problems is on cars with large upgraded turbos and cars that have low transmission fluid in the gearbox.
I wouldn't try and do it again. Once the clutches start slipping they can wreck themselves fairly quickly. Best to just get the filters and fluid changed along with fixing any leaks.
Thanks, this is the direction I'm heading. It's going to be raining and cold all weekend so not sure when I'll get the chance to get it up on jacks, get the undertray off and check for leaks. I wish the filters & Fluid was a DIY, but it seems a very specific process that can have disastrous results if done incorrectly.R.E92 said:
Quick update: Managed to get the car on ramps over the weekend and removed the undertrays. There appears to be some 'seepage' on one side of the trans oil pan. I'm hoping this is a symptom of a slow leak that has finally resulted in the fluid level being low enough to cause the overheat code. I'll get it booked in for a filter/fluid change as soon as i can (haven't driven it since the first incident to try to protect the clutches as much as possible). Just have to find an indy who knows the process to get that tricky last 1.5ltrs in (and not just a 'top up' when cold, leaving it still underfilled). Will update thread with progress.
I have had something similar happen to me recently.
The car is tuned. Auto 2.0
Pulling into a country road on the way to work, Sport/Manual mode. I put my foot down
started to accelerate down the road when the car seemed to suddenly over-rev. The power was cut, the dash lit up like a Christmas tree with the gear/cog on the display and a message on screen appeared telling me the car might not start again when the engine was stopped and to drive straight to BMW!
(very very butt clenching message)
I was about 2 minutes from work so I crawled to the office thinking that I would call the AA from there.
When I stopped and put it in park the message changed to something like "restarting the engine might clear the problem".
Turned the car off, counted to 10 (as you do), hit the start button and it started up like nothing had happened and all the lights cleared! I called the garage and booked it in for the next day anyway and then drove it home like it was made of glass after work.
After checking it the garage told me there were no active codes on the car and no sign of any leaks and such.
However... the error code history showed that the gearbox had registered a loss of contact with the engine, the engine showed a gearbox overheat and there was another one that was "basically the EMS going WHERE HAS THE GEARBOX GONE?" !!! All within a fraction of a second of each other.
The guys at the garage couldn't explain it other than 'maybe' a sensor glitch out. (and to have a dig about having it tuned.. they don't like it being tuned...)
I'm back to driving it normally now (but not quite fully trusting it yet). I really hope it was a random one-off.
The car is tuned. Auto 2.0
Pulling into a country road on the way to work, Sport/Manual mode. I put my foot down
started to accelerate down the road when the car seemed to suddenly over-rev. The power was cut, the dash lit up like a Christmas tree with the gear/cog on the display and a message on screen appeared telling me the car might not start again when the engine was stopped and to drive straight to BMW! (very very butt clenching message)
I was about 2 minutes from work so I crawled to the office thinking that I would call the AA from there.
When I stopped and put it in park the message changed to something like "restarting the engine might clear the problem".
Turned the car off, counted to 10 (as you do), hit the start button and it started up like nothing had happened and all the lights cleared! I called the garage and booked it in for the next day anyway and then drove it home like it was made of glass after work.
After checking it the garage told me there were no active codes on the car and no sign of any leaks and such.
However... the error code history showed that the gearbox had registered a loss of contact with the engine, the engine showed a gearbox overheat and there was another one that was "basically the EMS going WHERE HAS THE GEARBOX GONE?" !!! All within a fraction of a second of each other.
The guys at the garage couldn't explain it other than 'maybe' a sensor glitch out. (and to have a dig about having it tuned.. they don't like it being tuned...)
I'm back to driving it normally now (but not quite fully trusting it yet). I really hope it was a random one-off.
A
Anonymous
Guest
CFSD said:I have had something similar happen to me recently.
The car is tuned. Auto 2.0
Pulling into a country road on the way to work, Sport/Manual mode. I put my foot down
(very very butt clenching message)
I was about 2 minutes from work so I crawled to the office thinking that I would call the AA from there.
When I stopped and put it in park the message changed to something like "restarting the engine might clear the problem".
Turned the car off, counted to 10 (as you do), hit the start button and it started up like nothing had happened and all the lights cleared! I called the garage and booked it in for the next day anyway and then drove it home like it was made of glass after work.
After checking it the garage told me there were no active codes on the car and no sign of any leaks and such.
However... the error code history showed that the gearbox had registered a loss of contact with the engine, the engine showed a gearbox overheat and there was another one that was "basically the EMS going WHERE HAS THE GEARBOX GONE?" !!! All within a fraction of a second of each other.
The guys at the garage couldn't explain it other than 'maybe' a sensor glitch out. (and to have a dig about having it tuned.. they don't like it being tuned...)
I'm back to driving it normally now (but not quite fully trusting it yet). I really hope it was a random one-off.
What size tyres have you currently got fitted?
Possibly final update on my situation. I got a quote for $3,000 from BMW to do the job so ordered all of the parts including the Pentosin fluid (got 7 litres as I wasn't sure how much may have 'escaped' before throwing the fault code) from FCP Euro. Everything arrived about a week later - not bad from US to NZ with the current freight delays. Long story short, I put it on car ramps, jacked up the back to level (supported with axle stands) and did the job myself after downloading ISTA-D to run the refill process. Wasn't actually that hard but just a pain under the car - really needs a lift or at least those quickjacks to get a bit more access. Extra pain was that the Z4 seems to have a metal panel attached to the heat shrouds next to the transmission that necessitates removing a couple of heatshields so you can remove the metal 'plate' so that you can actually access the fill plug on the side of the trans. Not something that appears to be a thing on the E92's (watched a few videos on how to do this job, none specifically for the Z4, maybe I should have filled that gap of DIY knowledge by recording the process but too late now...).
Car is back up & running and I haven't experienced any issues since (been just under a week). Fingers crossed...
Car is back up & running and I haven't experienced any issues since (been just under a week). Fingers crossed...
A
Anonymous
Guest
CFSD said:
What are the widths?
Assuming they are either square or assymetric and you really have 40s on the back and 35s on the front then the rolling circumference difference front and rear is either 4% or 7%..the limit lies around 1.5% ish..in which case the DCS unit will have a melt down as your sizes are outside its parameters..
I had a not dissimilar thing when I intentionally provoked the car with all sorts of serious warnings (that dissappeared on re-start) with a 2.5% error based on an incorrect front tyre size..
A
Anonymous
Guest
Well it’s a 4% error so once you go to that territory you are on your own with regard to most DCS related functions… :thumbsdown:
A
Anonymous
Guest
CFSD said:Pbondar said:
So I should be matching front and back (ideally)?
Like I said the tyres were on the car when I bought it so changing them isn't an issue for me.
There AFAIK has not been published a specific figure but 1.5% is usually regarded as the maximum variation..
So yes external tyre circumference should be the same..
Who did the re-map…did you get a dyno run?
Pbondar said:
It was done by a place in Warrington, DC Remapping. Full dyno custom tune.
That was over a year ago now and until this strange event the car has been faultless.
Since having it checked over the car seems perfectly fine again. Very strange... I'm actually starting to think maybe I downshifted by mistake.
A
Anonymous
Guest
Usually these DCS ‘failures’ occur when you do something extreme and then the systems that are fed by the DCS throw a wobbly..I had one when I was doing extreme hard starts with traction off…it threw a wobbly similar to yours with no subsequent recorded issues..
In my case the tyre supplier had fitted an under profile front tyre which caused the difference in rolling circumstances..
In my case the tyre supplier had fitted an under profile front tyre which caused the difference in rolling circumstances..
