tbourner Posted June 23, 2014 Share Posted June 23, 2014 Not Supra! Our new (to us) Micra auto is playing up after 4 days, it's an 03 plate 1.4 auto, but I know nothing of auto boxes really, so asking for thoughts. 1st to 2nd seems OK, in gear it seems to do everything it should - not slipping etc., but going from 2nd to 3rd yesterday the revs went up by a few hundred rpm (depending on how hard I was accelerating at the time) before engaging 3rd. My guess was some kind of solenoid to select gears, or the torque converter itself? Like I said I don't know how they work really. It's on 80k miles and I don't think the fluid's ever been changed, would that do it? It was happening yesterday after half hour to an hour of driving around town, didn't happen this morning when cold. Also, when stopped the battery light sometimes flickers on, not sure if that might be related - it had a new battery put on about a week ago. Quote Link to comment Share on other sites More sharing options...
Tayfun.tugra Posted June 23, 2014 Share Posted June 23, 2014 What colour is the gearbox fluid? If its gone a. Brown colour and stinks it may be a brake band... The battery light may be alternator Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 23, 2014 Share Posted June 23, 2014 alot of time with odd gear changes its the level , but if its browny black in colour do a oil change and see how you go from there Quote Link to comment Share on other sites More sharing options...
tbourner Posted June 23, 2014 Author Share Posted June 23, 2014 So reading the HowStuffWorks website it sounds like the bands stop the different parts from moving, to transmit the power through the appropriate ratio? Does that mean 2 bands need to activate for 3rd gear but only one or the other to get 1st/2nd/OD etc.? So if 1st-2nd is OK but 2nd-3rd is bad would suggest it's not a band problem, otherwise the issue would show up between other changes? I don't think we've had it in OD yet. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 23, 2014 Share Posted June 23, 2014 (edited) Inside auto boxes there are external brake bands, and internal friction clutches in 99% of them. "Flare" of revs between gears equals slippage. Slippage in auto boxes equals big bills. Don't drive it until it's sorted. If the fluid from the dipstick is other than clear red, like a decent red wine, or smells burnt, it's probably too late. Changing the oil will not put the friction material back, and it's only a few thousandths of an inch thick to start with! Small auto boxes, in my experience, are less reliable than big ones, as they have space issues so things are never very robust inside them. I have a pal who is a driving instructor and he stopped running automatic small learner cars as he was sick of the repair bills. New York cab drivers order cars with hard shift valve bodies, as even normal slippage that gives soft changes equals more wear. The choice between you and your passengers having sublime gear changes, or an extra 100K miles from the box is a no brainer to them Edited June 23, 2014 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
tbourner Posted June 23, 2014 Author Share Posted June 23, 2014 Thanks, Chris, that's worrying! Everything I've read up so far suggests it's not a clutch pack though. I've just done some reading on 'flare' in autos as well: http://www.uksaabs.co.uk/UKS/viewtopic.php?f=3&t=101620 [software update to fix it.] http://forums.nicoclub.com/transmission-flare-update-anyone-with-tranny-issues-similar-please-read-t311262.html [All sorts of fixes attempted such as cleaning MAF sensors! This one only happens when cold though, opposite of mine.] http://www.saturnfans.com/forums/showthread.php?t=27180 [TSB to replace the "valve body".] http://www.2carpros.com/questions/1998-honda-civic-transmission-flare [Could also be valve body (what's a valve body?), also talks about reflashing ECUs and eventually concludes it's the PCM at fault (powertrain control module?).] None of them seem to even mention worn clutches as a potential cause. That last link is very similar to my issue as well, page 6 says: If the CPC valve is faulty, you would be getting the problem all the time, either cold or at operating temperature. For transmission, actually the reverse is true of slipping. They tend to slip when cold and works well at operating temperature as pressure losses are reduced when components and seals heats up and expands. Yours is slipping only when at operating temperature which is the reverse and I would lean towards a sensor fault. Sensors could be sending signals that are interpreted too slowly or slightly out of range and this could be a fault of the PCM or its software. TPS, ECT, VSS, Linear solenoid, shift solenoids are all possible fault areas. I've no idea what electronic control the K12 Micra has, I'm guessing it's all ECU controlled though - maybe it needs a remap. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 23, 2014 Share Posted June 23, 2014 The thing with slippage ("flare"), is it wears out clutches and / or brake bands, fast! How old is the thing? It may be able to self diagnose and give some fault codes. I steer clear of auto box work, but know a good specialist you could perhaps ask? Quote Link to comment Share on other sites More sharing options...
tbourner Posted June 23, 2014 Author Share Posted June 23, 2014 It's an 03 plate, so 11 years old. 80k miles. There's a gearbox specialist near me, I might ask their advice - I'm guessing Nissan will just want to replace the whole box and electronics either way. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 23, 2014 Share Posted June 23, 2014 I doubt an 03 car will have much OBD capability compared to the new stuff. But new stuff has that much crap on them they need good on board diagnosis Quote Link to comment Share on other sites More sharing options...
tbourner Posted June 23, 2014 Author Share Posted June 23, 2014 Atf looks nice and clear red and at the right level. So that's one positive. Quote Link to comment Share on other sites More sharing options...
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