Over revving V6

[Darryl]

My V6 has started to over rev when changing from 1st to 2nd and 2nd to 3rd. This only happens when the engine is warm, when it is cold the over revving is not such an issue.

The auto box tries to change up at the right revs, 2500 ish but then spikes to 3500 before seeming to catch the next gear and away we go.

Any suggestions, i've just been quoted 1.5 hrs labour at £65/hour plus oil and vat so nearly £200 to drain, clean and replace ATF. Does this sound like a good place to start.

Thanks

[mikeonb4c]

My V6 has started to over rev when changing from 1st to 2nd and 2nd to 3rd. This only happens when the engine is warm, when it is cold the over revving is not such an issue.

The auto box tries to change up at the right revs, 2500 ish but then spikes to 3500 before seeming to catch the next gear and away we go.

Any suggestions, i've just been quoted 1.5 hrs labour at £65/hour plus oil and vat so nearly £200 to drain, clean and replace ATF. Does this sound like a good place to start.

Thanks

I'd get a Bongo specialist to look it over rather than just accept the proposed solution and cost from a n other garage. Madmile is a professional Bongo converter not far from you and may be able to recommend someone local and Bongoworthy. Good luck and keep us posted.

[Darryl]

Thanks for that, any info on local garages would be appreciated.

Do you think the oil change is a good starting place as i have only had the Bongo for 3 months and there is no history of an ATF oil change. The garage said they checked it and it seemed ok but i think the level was checked when cold..

I plan to check the level this evening with engine running etc to get a more accurate reading. Could low ATF cause it to over rev?

Thanks

[mikeonb4c]

Thanks for that, any info on local garages would be appreciated.

Do you think the oil change is a good starting place as i have only had the Bongo for 3 months and there is no history of an ATF oil change. The garage said they checked it and it seemed ok but i think the level was checked when cold..

I plan to check the level this evening with engine running etc to get a more accurate reading. Could low ATF cause it to over rev?

Thanks

Try PMing BF member 'Alacrity' (if he doesn't spot this thread and post on it) as he is a pro gearbox specialist and a Bongo owner. From what I've read on here (and given I know very little about techie stuff), I've not heard of a connection between low ATF level and revving (though it could be true). I presume you don't really mean the engine over revs as such, but that the autobox only changes up after the engine has (been) revved excessively?

[Darryl]

The engine revs go up to 3500 ish but the bongo does not accelerate until it seems to catch and then the revs drop and away we go again.

[TerryG]

The engine revs go up to 3500 ish but the bongo does not accelerate until it seems to catch and then the revs drop and away we go again.

I'm no expert but that sounds like torque converter slip to me.

[mikeonb4c]

The engine revs go up to 3500 ish but the bongo does not accelerate until it seems to catch and then the revs drop and away we go again.

I'm no expert but that sounds like torque converter slip to me.

Indeed. And maybe low ATF fluid level could cause that (I wouldn't know). PM Alacrity BUT FIRST have a search on here for past threads in case effects of 'torque converter' or 'fluid level' have come up before.

Incidentally, has it been working fine up until recently? And is there any reason to suspect ATF fluid loss? You see where I'm going with this

[Darryl]

Has been getting worse over the past few thousand miles, was originally there going from 2nd to 3rd but now 1st to 2nd aswell. No loss of ATF but have also only checked it when cold and stationary.

it goes well with the foot to the floor and holds in top fine even, on inclines.

I'll check level this evening and report back.

[mikeonb4c]

Has been getting worse over the past few thousand miles, was originally there going from 2nd to 3rd but now 1st to 2nd aswell. No loss of ATF but have also only checked it when cold and stationary.

it goes well with the foot to the floor and holds in top fine even, on inclines.

I'll check level this evening and report back.

Its seems a little odd that the situation is getting worse and yet ATF level has remained unchanged. Check ATF level (and condition/colour/smell) but maybe hold on to your £s until Alacrity (or an autobox specialist) has given you their opinion. Have you tried doing some googling using, for example, 'symptoms of slipping torque converter' or 'symptoms of low automatic transmisison fluid'. I just did and I got lots of interesting reading.

[dandywarhol]

Torque converters always slip, that's why they have a lock up facility. Sounds like you at least need the fluid changed and filters cleaned ASAP - Mazda recommend every 25,000 miles for a fluid change from memory

[teenmal]

Has been getting worse over the past few thousand miles, was originally there going from 2nd to 3rd but now 1st to 2nd aswell. No loss of ATF but have also only checked it when cold and stationary.

it goes well with the foot to the floor and holds in top fine even, on inclines.

I'll check level this evening and report back.

Hi,
You need to check the level when the engine is running and the gear selector in Park.

Cheers..

[Darryl]

Checked oil level. Could hardly tell where the level was as the oil was so thin but seemed on the level. Maybe the viscosity is to thin, degraded over time!!!!

I now need to find a gasket before the local garage will drop the sump. Any other ideas?

Could thin oil be the problem....

[dandywarhol]

Unlikely, get the filter in the gearbox cleaned for starters otherwise you're going to burn out the clutches and be into an expensive 'box overhaul. The oil should have a sweet smell, if it smells burnt then you've left it too long...................

[missfixit70]

ATF change is easy enough that you can do it yourself & I can almost guarantee you won't need a gasket - http://www.igmaynard.co.uk/bongo/forum/ ... atf+change

[The Great Pretender]

Any other ideas?



Yep, try a new fuel filter.