Warm up time and holding the gears

[roosmith]

Yep me again, I'm being a pain! Sorry!

The time it takes for my Bongo to run normally and take the correct gears seems to be getting longer. Not sure if it is my perception or if this is correct! It is holding 2 gears down until my engine is at about 75 degrees. It means I can't do much more than 50 miles an hour without it sounding like it's about to expire.

I'm sure it only used to hold the top gear and certainly changed before it hit 75 degrees. Where is the temperature measured, is it gearbox or engine? Do these sensors breakdown gradually or just stop working?

[Fassi]

As i first read this it makes me think there is a problem with the throttle position sensor. With a bit of heat making it work correctly by reducing resistance somewhere. This is an out and out guess by the way and I was at the pub for lunch. The temperature doesn't or shouldn't select gears?

[Fassi]

Have you checked the gearbox oil level?

[mikeWalsall]

Low gearbox temperature stops the gearbox / torque converter going into lockup / top gear ..

[roosmith]

Thanks Mike, I knew I'd read that on here and mine has always done it so I took it as gospel. How does it do it though, how does it know it's warm?

With regards to throttle position sensor, it's not the throttle that is causing an issue, it's the gearbox in a lower gear. Also would mine have one, as I've only come across them on fly by wire systems?

[Simon Jones]

As I recall, it will stay in 4th gear until it gets warm (usually a few minutes) and then it will go into top gear lockup. It does this to ensure the fluids get up to temperature as quick as possible. From your description, it sounds like yours isn't getting out of 3rd gear which is not right. Not entirely sure where it gets it's temperature reading from (engine or gearbox) but it could be a dodgy sensor.

All Bongos have a throttle position sensor (TPS) which is used to tell the gearbox ECU how it's been driven so it knows when to knockdown. In the case of the V6 it also changes the rate at which the fuel is injected. It could be a problem with the TPS but you would not normally expect it to go away when warm, but it's not impossible. I'd certainly start by checking the gearbox ATF level and if you've got no record of it being changed (or it brown and smells of burnt toast), drain the fluid, drop the sump to clean the filter and refil with Dexron 3 fluid.

[roosmith]

Thanks Simon. It's been on the list of nice to do jobs for a while but always been dropped down the list by ones that were essential! It looks in good condition but perhaps I need to just get on with it now and get the oil changed. In theory it's 90k old now.

[Simon Jones]

According to factsheets in the members area, the ATF should be changed every 2 years or 24,000 miles so you may be a tad over .

http://www.igmaynard.co.uk/bongo/member ... hedule.pdf
http://www.igmaynard.co.uk/bongo/member ... ts/atf.pdf

[mikeonb4c]

According to factsheets in the members area, the ATF should be changed every 2 years or 24,000 miles so you may be a tad over .

http://www.igmaynard.co.uk/bongo/member ... hedule.pdf
http://www.igmaynard.co.uk/bongo/member ... ts/atf.pdf

Every 2 years! Blimey Charlie i'd thought it was just every 24k miles. I suspect very few have ATF changed that often though now i've been advised i reckon i'd better get it on the to-do list.

[Bob]

Yes, mine is rather overdue.

[mikeonb4c]

Yes, mine is rather overdue.

Laxative helps I find

[Bob]

Yes, mine is rather overdue.

Laxative helps I find

Micheal...

[cmm303]

According to factsheets in the members area, the ATF should be changed every 2 years or 24,000 miles so you may be a tad over .

http://www.igmaynard.co.uk/bongo/member ... hedule.pdf
http://www.igmaynard.co.uk/bongo/member ... ts/atf.pdf

Every 2 years! Blimey Charlie i'd thought it was just every 24k miles. I suspect very few have ATF changed that often though now i've been advised i reckon i'd better get it on the to-do list.

suspect mine is overdue by 75k miles

[Northern Bongolow]

check 19-444 on this link, take it out and clean it or check/clean the wiring to it, its an inhibitor switch, which sounds like a temp activated switch.

http://lushprojects.com/bongopartsmk2/c ... o=.html#14

[roosmith]

Spot on, thanks Northern, missed that exploded diagram when looking at the weekend.