Diesels and Automatic Gearboxes

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Soldato
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Hi all,

Looks like I'm about to give up looking for a Petrol S-Max, it's just too painful, there are hardly any about and of the ones that are they're not in decent shape. Looks like I'm going to have to go for a Diesel car... I'm considering as far back as 2007 (pre-DPF fit) and onwards, budget around £8-8.5k. Might just take the car for a stretch and ensure its running up to temp for 15-20 mins each week/2 weeks if I get a DPF fitted one (2008 onwards).

I've seen a few Automatic Diesels knocking about, my question is, if I were to go for an 07'-09' Diesel what should I be looking out for / expect to go wrong / expect to see having been done service wise / expecting to see done soon...

Mileage wise I'd be looking at around the 60k mark or thereabouts.

Also, regarding auto gearboxes... what can go wrong with these compared to a manual gearbox and how much are they to repair if things go wrong comparatively?

Cheers for any help.
 
Generally, auto boxes need oil changes - despite the likes of BMW claiming the oil will last the life of the car - it won't.
Can you imagine the state of a car engine with 100k on the clock but no oil changes? As a rule of thumb, every 60k for an automatic transmission fluid flush is a wise precaution IMO.

If the 'box failed at the age of car your looking at - depending on the make / model - in the event of a failure I'd source one from a breaker!

This was the plan with my old automatic 328,728,528 and my current 530i as the rebuilding costs are huge,thankfully not yet required though!

Most autos should outlast the car so long as it's not been abused and has had fairly regular oil changes.
 
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I'd go 40k. I believe that's the interval for DSG gearboxs and it is the interval for my CVT(Multitronic) gearbox.

Ignore anyone who says they are sealed for life as said above.
 
Antony101 said:
It's barely a pain, just make sure that the oil is changed every now and then.
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This.

An automatic is great if its - general- lazy manner suits you, whilst yes they can fail, in fairness I'm yet to have one that has (touch wood!) - and I've ran a fair few over the years.

Your going to be facing a considerable bill if a manual box fails don't forget, but above all bear in mind that - despite horror stories - chances are that either a manual or auto won't necessarily fail on you either! it is still a rare problem in the grand scheme of car ownership IMO.

If an auto suits you then don't discount it, just be aware around the 60k mileage margin that a transmission fluid swap in the auto would be a wise precaution.
 
To be fair you'd want to change the fluid in a manual gearbox at the same intervals anyway to ensure a decent life. The whole 'sealed for life' thing applies to manual boxes too and is just as stupid.
 
My mums audi CVT box went and it cost £1200. I would think a dead manual box is probably going to cost similar money so no worse off. Although I suppose its the frequency of failures that is the highest concern.
 
I've never had a car warranty before, I suppose it would be a good idea to get one? Would automatic gearboxes be covered by them? I don't know anything about car warranties.
 
EddScott said:
My mums audi CVT box went and it cost £1200. I would think a dead manual box is probably going to cost similar money so no worse off. Although I suppose its the frequency of failures that is the highest concern.
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The frequency of failures is the issue, an automatic box is inherently much more complex than a manual box therefore the chance of something going wrong with it is greater.
 
[TW]Fox;28321995 said:
Presumably this 60k mile figure is plucked from thin air?
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Wtf lol?

Most auto manufacturers recommend it, for instance, this is from ZF:

Depending on the driving style (e.g., many trips at high speeds or sporty driving), ZF recommends a transmission oil change every 80 000 to 120 000 km, or after 8 years at the latest.
 
pepsilol said:
Wtf lol?

Most auto manufacturers recommend it, for instance, this is from ZF:

Depending on the driving style (e.g., many trips at high speeds or sporty driving), ZF recommends a transmission oil change every 80 000 to 120 000 km, or after 8 years at the latest.
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Where is the recommendation from BMW that you should change the transmission fluid at 60,000 miles? Whilst the sealed for life thing is hilarious 60,000 miles is well within the warranty period offered by BMW for the gearbox on a new car (and many cars they warrant as used cars will be around this). You would think that if it was that important they'd mandate it as part of the service schedule as it would have two key benefits:

a) It generates additional service revenue
b) It would reduce the amount of cost of transmission warranty claims

Yet despite both of these they've not done it. Why?
 
I don't know why but any sensible person would rather follow the manufacturers advice.

Lexus/Toyota and Honda do stipulate a transmission service as part of their routine maintenance. Maybe they just want their **** to last longer?
 
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[TW]Fox;28322897 said:
Where is the recommendation from BMW that you should change the transmission fluid at 60,000 miles? Whilst the sealed for life thing is hilarious 60,000 miles is well within the warranty period offered by BMW for the gearbox on a new car (and many cars they warrant as used cars will be around this). You would think that if it was that important they'd mandate it as part of the service schedule as it would have two key benefits:

a) It generates additional service revenue
b) It would reduce the amount of cost of transmission warranty claims

Yet despite both of these they've not done it. Why?
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I agree. Although personally I would be happy to change the oil if my car hit that sort of mileage most other drivers don't or won't and theres plenty of high mileage auto BMWs now and hardy any gearbox failures.
 
I hated doing a fluid change on my car, the ATF stinks and I had the car on stands so it was just awkward and unpleasant. The fluid was surprisingly expensive too.
 
BMW don't want to change the oil in my ZF8HP gearbox as part of the service schedule, so it probably won't ever get changed.

To the poster likening transmission fluid to engine oil in terms of how it might "feel" after a lifetime without being changed: A lot of the reason for the changing of oil is down to the breakdown of the qualities of the oil through heating and mechanical damage, but another very large chunk of the reason for changing the oil is dissolved particulates from combustion, dissolved fuel and of course any metal (however minimal) from engine wear over the duration the oil was circulating through the engine. Gearbox oil isn't subjected to much if any of the latter aspects.

Gearbox oil damage through regular mechanical wear will thin the oil over time, but the oil isn't there in a role that is primarily lubrication, it is there as a hydraulic working fluid so as long as the compressibility doesn't change too much then there isn't a huge problem.
 
[TW]Fox;28321995 said:
Presumably this 60k mile figure is plucked from thin air?
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No, it was "plucked" from the chap who changed my ATF fluid about three months back.

It was black and treacle like on removal, he wasn't surprised to see it like this, the car has done nearly double the 60k figure he mentioned.

The box is much smoother now and the gearbox warning light (yellow cog) has not come back on since.

Presumably I should have not touched it because its sealed for life and awaited the boxes demise?
 
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