Guys, 2001 BMW320i . Drives well from cold gears change no problem, very smooth. However when stopped hot then re-started gears clunk/thump/jerk into next gear. Only when stopped from hot. Feels like the throttle isn't shutting off between gear changes. Recent oil/filter change. Did show a fault with faulty temp sensor in the gearbox. Would that be the cause? Keen for your thoughts.
Aftermarket ones can be bought from Ebay for a reasonable price. They take about a week to get here from the USA.
kazbanz,
Jul 25, 8:43pm
is it mostly the 1-2 change? how high is the idle with the car hot?
cabrio1,
Jul 25, 10:03pm
Thanks for the replies. Happens through all gears but only when hot. Will check the idle and get back. You know when it's going to happen, when shifting from park to drive a noticeable jerk from transmission. Not extreme but there. Then as it shifts between gears more noticeable. 4 th and 5th worst of all, very noticeable.
cabrio1,
Jul 25, 10:08pm
Yes those are a reasonable price. I might try a local breaker to see if that will fix it short term. Had a transmission oil change and the guy fault coded the car and said something about a faulty temp sensor in the trans. He said the valve body needed to be removed to get to it? Any comments on that theory? Used to be intermittent, now becoming a more regular occurance.
intrade,
Jul 25, 10:15pm
coolant temp sender be the first thing i would check normally global obd2 will show coolant temp sender of engine managment it will shift different when cold the only thing you also would want to see trans temp sender and now that temp sender is factory only non global obd as the temperature of trans fluid has nothing to do with emissions if it was old fluid it would more be the other way and improof when fluid gets thinner on heating up. but if it reports wrong temp is shifts harsher as it thinks the fluid is still cold and thick. thats just a conclusion when you flick the switch in the brain to on position as to what i be looking at as first action with these symptoms.
intrade,
Jul 25, 10:27pm
mass airflow can also cause roblems on trans shifts you would need a oscilloscope to correctly test a mass airflow meter depending on what you have on the car bosch made a test cable to bench test the hfm-5 mass airflow meter on a workshop bench. all things to see what you have fitted you test the most probably things first before you go and start swapping parts , Also a battery load test would be good thing to do even do with a electronic battery analyzer just to rule that out , i usually do battery check and alternator ripple test in one go with my pico scope hook up to rule 2 main knowen problem areas out , but alternator ripple only present when hot well yea maybe, but not most likely as cause. Most likely stuff first and from the most likely ones the easy ones first. voltage drop to ecu can also easy be done with the loadpro test lead from dan sullivan and a multimeter.
cabrio1,
Jul 25, 10:37pm
thanks for the replies, I might take the car to a local Indy workshop and pass these thoughts on. They "specialise in BMW" but I'm always dubious. They should have the equipment to test it out for me. I did put a new maf sensor in a couple of years ago, might be worth giving the old unit a clean and popping it back in?
budgel,
Jul 25, 11:27pm
A remote temperature reading laser gun would be useful in diagnosis. Just point the dot at the trans when it is misbehaving and find out what the temperature is. It shouldnt be hotter than the coolant temp. If it is hotter, it will be a heat exchanger issue, if not, possibly the sensor.
monsieurl,
Dec 27, 12:10am
I'm assuming it's a Jap import!? All signs point to you having the "Jatco jerk"! Google it or join Bimmersport for more details!
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