 | Home > Technical > 2.2 Rev drop or not? |
 
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| YOLO110 Member Since: 14 Feb 2015 Location: Perth Oz and Stansted UK Posts: 1642  
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I am really struggling to get an answer to this annoying characteristic on my MY14 Puma.
When I am changing gear, the RPM stays at a high level for 1-2 seconds before it would drop back to idle. So if I am changing from 3rd to 4th and rev the engine to say 3,500 RPM in 3rd, when I change gear, into 4th, the RPM 'hangs' at that (3000 RPM ish) higher level. I have never experienced this is any car I have ever driven... when you take your foot off the accelerator, one would expect the RPM to drop to idle! It does not and it's really annoying... 
Is this normal for the 2.2? (BAS... can you 'map' this out on a 'City Tune')? Cheers, Pete.  YOLO... You Only Live Once... |
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31st May 2015 10:09pm |
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| K9F Member Since: 12 Nov 2009 Location: Bournemouth Posts: 9610  
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Look up "Rev Hang" under the search facility, plenty of information about this 2.2 characteristic there.
 If you go through life with your head in the sand....all people will see is an ar5e!!
Treat every day as if it is your last....one day you will be right!! |
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31st May 2015 10:21pm |
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| jomara Member Since: 26 Oct 2009 Location: Lanarkshire Posts: 1790  
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Hi Pete
Do a search for rev hang and you'll see how common this is!! I know Pete Bell posted a while back that he was looking at a solution for the hanging issue but I'm not 100% sure where it's at
Cheers John 2014 110 2.2TDCi XS Station wagon 1971 Bowler Tomcat 88 4.2 V8 Auto 2022 110 D250 XS Edition - Gone 2024 110 D250 X-Dynamic HSE |
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31st May 2015 10:21pm |
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| YOLO110 Member Since: 14 Feb 2015 Location: Perth Oz and Stansted UK Posts: 1642
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Thanks for the pointers guys...
So, it's common... but it's just NUTS! Off to get a Transit ECU now!!  YOLO... You Only Live Once... |
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31st May 2015 10:44pm |
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| YOLO110 Member Since: 14 Feb 2015 Location: Perth Oz and Stansted UK Posts: 1642
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LOL!
I find that 'waiting' with the clutch in until the revs drop back works ok... It's just tedious however and this hanging certainly does not help with the drive line back lash!!  YOLO... You Only Live Once... |
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31st May 2015 11:12pm |
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| Pickles Member Since: 26 May 2013 Location: Melbourne Posts: 3784 
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Yes Pete, my issue exactly,...going from 5th to 6th, I do wait sometimes, seems like an eternity, for the revs to drop, & I still stuff up the gearchange, resulting in various clunking noises!
Pickles. |
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1st Jun 2015 1:13am |
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| Hanechdene Member Since: 18 Sep 2014 Location: High Wycombe Posts: 62 
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We are experiencing this in ours.
We complained numerous times to the dealership regarding this expressing concerns of the damage it is doing to the drive train and also how unsafe it is when reversing trailers to suddenly find the vehicle accelerating on its own accord 
The main concern is the affect of the backlash on the drive train. Land rover apparently are asking dealerships to measure the amount of backlash which they have completed on ours. However land rover now want it back for a few days to complete some more tests / measurements. |
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1st Jun 2015 6:15am |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17372 
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Will that work? I don't think so. |
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1st Jun 2015 8:19am |
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| Supacat Member Since: 16 Oct 2012 Location: West Yorkshire Posts: 11018 
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Is this the same rev hang feature or do you have a different issue? |
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1st Jun 2015 9:29am |
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| Hanechdene Member Since: 18 Sep 2014 Location: High Wycombe Posts: 62
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Part of the same rev hang.
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4th Jun 2015 6:51am |
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| RobKeay Member Since: 19 Jul 2009 Location: Stafford Posts: 1579 
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The rev hang on the puma engine is to prevent backlash if you work with it rather than fight it.
If you are revving the engine to 3k plus you are giving it some. So try changing gear as fast as your driving. If you let the revs drop to below 1800 the road speed won't match the revs and you are out of the torque zone so less power. This will make for a bumpy ride. Normal driving I'll change around 2.2-2.4 revs and the Rev hang doesn't happen and your driving with the torque. When I am giving it the beans revving above 3k revs I change quick and pretty much beat the Rev hang. I also never fully let my foot of the accelerator. I think of it like this if your double clutching an old car your matching the gearbox to the road speed. This Rev hang thing is trying to help you remove the back lash and not damage your car. The trick is not to fight it and drive the defender with care. You know when your changing well the defender will be pretty smooth. If you look on the internet lots of new cars are now doing this. |
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4th Jun 2015 8:01am |
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| YOLO110 Member Since: 14 Feb 2015 Location: Perth Oz and Stansted UK Posts: 1642
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You just don't need 'rev hang' to ensure good smooth gear changes with no backlash.
Perhaps this is 'aimed' at the uneducated driver who has never driven a Defender... and jumps into one and tries to drive it like a car. You cannot do that... as was so badly demonstrated by a new car salesman who took off down the road like he was trying to drive a Fezza! Clunk, crash, backlash... awful! I am sure there are a lot of us out there who know how to drive 'around' an 'old fashioned' transmission system.. but the rev hang just gets in the way. All IMHO!  YOLO... You Only Live Once... |
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4th Jun 2015 10:36am |
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| Pickles Member Since: 26 May 2013 Location: Melbourne Posts: 3784
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Pete,....CORRECT.
Martin. |
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4th Jun 2015 9:47pm |
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| Beery Member Since: 16 Nov 2014 Location: NSW Posts: 36 
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That sounds more like the "anti-stall" feature preventing revs dropping too low |
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5th Jun 2015 1:54am |
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