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This is a simple part to change, but if left can give you no end of trouble and headaches.
It is the Automatic gearbox diaphragm on the side of the gear box underneath near the PPF and gearbox sump and is a valve for a vacuum which helps with the gear change with the breather hose which runs to the back of the inlet. This little thing can stick open resulting in automatic gearbox oil being sucked up into the inlet chocking the roadster.
Giving of major blooms of white smoke as it tries to burn it off.
Please view the pictures below of the Auto that has had the diaphragm fitted after the old one failed...
Vid 1....
https://youtu.be/yQ4jRs3RN5g
ViD 2....
https://youtu.be/CB3fCr-5ZoY
Vid 3
https://youtu.be/3tl6DulQLEE
****CLICKING ON THE IMAGES WILL ENLARGE THEM FOR BETTER VIEWING****
You will think the Roadster is dead, it will give you a headache to clean it all and make good to get running back right again.
Worse cases have been owners going to garages over this and getting a big intake of air through the garage owners teeth with a " it's fudged, needs a new engine"
Some owners have gone this route not knowing any better and lack of knowledge on the garage owners side also.
Please understand there is nothing wrong with the engine, nothing that a good flush clean, plugs and the new diaphragm and V power petrol should solve.
The part that fails is not the biggest of units and is a old school carry over, new automatics don't have them, and will take no longer than 30 minutes to change, with jacking, swapping and adding fresh gearbox oil.
We highly recommend you change this forgotten part now. Before it happens. Because it will at some point just like the UK spec immobliser issue, it is not "if" but when, if it happens, try and clamp the hose at the back of the inlet in the engine bay (pics #1 & 2) and you should be able to crawl her home, or get her uplifted to be safer, never tow on the back wheels with an auto.
Locations of the diaphragm hose in the engine bay on the
back of the inlet...
#1.....
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#2.....
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This will talk you through the little lurking demon part and how to change it...
MK 1 1.6 ( on the left) auto is slightly larger than the 1.8 (on the right) auto item...
New MK 1.6....
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New MK 1 1.8....
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First off buy a new unit for your correct version from the likes of Autolinkmx5 LINKS>>>>>>>>....MK 1 1.8.....https://www.autolinkmx5.com/automatic-g ... 7258-p.asp MK 1 1.6....https://www.autolinkmx5.com/automatic-g ... 0547-p.asp ,and new plugs.... DO NOT even contemplate getting one s/hand, these are like little ticking time bombs and you will not know how long you have with a s/hand item.
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Wedge the drivers side wheels front and back and jack up the passenger side and rest onto axle stands( we got her up in the air on all four so we could take pics)
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Locate the little hidden devil unit....
MK 1 1.6 version...
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- IMG_20190608_191548.jpg (548.36 KiB) Viewed 10504 times
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Mk 1 1.8 version....
It is a lot easier to get to than on the MK 1 1.6 version, the process is the same for removal and draining the box ,then refitting and refilling, the only difference being that you do not need to remove the hose clip on the sump with there being more space/room to work in...
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Put a tray with a plastic sheet down and have rags at the ready as there will be a little bit of gear box oil lose which we leave to drain and add fresh when finished...
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MK 1 1.6 only.....
Get a 1/4 drive ratchet ,extension and 10mm socket and locate the hose bracket that bolts to the gear box sump and undo and remove the 10mm head bolt and bracket and put them somewhere safe for re-fitting...
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Disconnect the rubber hose by simply just pulling it off and free from the unit...
Mk 1 1.6 version...
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- IMG_20190608_192149.jpg (520.62 KiB) Viewed 10504 times
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Mk 1 1.8 version...
It is the same process as the MK 1.6 version
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Now get your mole grips,( we used long nose) to grip and break the seal...
MK 1 1.6 version....
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- IMG_20190608_192842.jpg (516.72 KiB) Viewed 10504 times
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MK 1 1.8 version....
Same process as the 1.6 version.
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Once loose, just turn it out with your hand, there will be oil trying to make a run for it so be ready...
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Once out and the old oil is all drained off it is just a case of screwing the new one in, have it close by hand to fit straight after the old one comes out..
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Now it is the same procedure as removal....
Get your new diaphragm and once screwed back into place by hand, use your grips etc to just nip it up nice and tight again so we get no oil leaks...
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Push the rubber hose back on and the hose bracket and sump bolt on the 1.6, then it is just a case of getting her back on the floor....
Mk 1 1.6 version....
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MK 1 1.8 version....
Same process as the MK 1 1.6 version only there was no need to remove the hose bracket to the sump for the 1.8 version.
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Now we need to add our fresh oil which is Dextron II power steering and auto gear box oil 7 ltrs for the 1.6 and 7 ltrs for the 1.8 down the auto gearbox dip stick tube (yes that is the correct way to fill it) locate and remove the dip stick...
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And start to fill up to the level...
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To the dip stick mark shown below (All versions)....
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Once at the correct level, put the dip stick back into place....
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If it had failed then we do recommend changing the spark plugs also for a better spark as the plugs have had to try and ignite oil that should not be there so they will be gummed up....
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Once all this is done (if we are changing because it did fail) we recommend filling up with a good cleaning fuel like V POWER and going for a good long run hitting a motorway if possible to get those revs up so it will blast and burn the oil through the system, pottering around the village will not help to clear it.
This may take a good couple of weeks before she is back to normal, but it will clear and sort itself out.
If you had stopped straight away when it failed and had her flat bedded home it will sort its self out quicker with the lack of gear box oil hitting the system.
The one in this guide was nursed home so ended up from around a ltr to 2 ltrs in the system to be burnt off through the system which was a major clean, inlet was removed and deep cleaned, injectors with one needing to be replaced and all having new seals, air trunking was removed and replaced,AFM was cleaned, throttle was cleaned and new gasket added , 3 sets of spark plugs in the sorting out time, new zorst and cat which may of been over kill, but we drive/nursed her home so the oil was in everything .
But she is not dead as some garages will tell you.
This is the first time I have hit this or heard of this fail, but I will make sure that this will never happen again to me by changing this diaphragm as a course of action when the next automatic version hits the workshop.
Before you hit this headache get it changed asap and forget about it ever happening to you, my misfortune is for your gain.
She is back running again bouncing up and down motorways better than ever like nothing has ever happened .
Hope this helps as it was something I personally hit and there is not much out there on the subject, as the norm any question please feel free to ask, its what we are here for.
M-m
