Automatic diesel judders and struggles to accelerate above high speeds....

General_query

Just found this, definitely beyond me. Fine if you are technically minded / gifted, but I'm not. 
https://youtu.be/ZZc9VcSy4Uk

General_query

daveyjp said:

Age, mileage?  When was the gearbox oil last changed?

Sorry, it's a 2011 Vauxhall Meriva Exclusiv 1.7 CDTI (Automatic).
Just passed 60,000 miles, I usually do 7k miles a year but doubt it's even done 2k since lockdown. I do however take it out on a 30 minute run on the M62 every fortnight to clear the DPF (was told to do so by place I bought it from). That's about as technical as I get I'm afraid.

I have no idea when the gearbox oil was last changed, sorry

Last service details are posted above, and I've had it since 2017.

General_query

Found this, but still means nothing to me
https://www.honestjohn.co.uk/forum/post/index.htm?t=105100

daveyjp

If the oil has never been changed this may be part of the problem.  Sluggish changes, lack of acceleration can be signs of oil which is turning into treacle.

At ten years old it really is time to change it regardless of any other issues with the car.

greyteam1959

Get to your local independent garage & ask them to change the fuel filter.
Probable total cost £25.

General_query

Thank you all.

So, it's either or all of the following:

• Mass Airflow Filter/Sensor (MAF)
• Fuel filter
• Gearbox oil

Thing is, I always get its annual service and MOT (done on same day) at my local garage and so I'm guessing unless I specifically ask for for them to look at the MAF, and change the fuel filter and gearbox oil they'll just do the usual Oil, Oil Filter, Air Filter & Cabin Filter which is expensive enough as it is what with parts, 2 hours labour charge, then the £45 MOT on top, usually totals £250 - £270, but will exclude any MAF repair, fuel filter and any gearbox oil.

Do you then think the Vauxhall £305 price for a Major Service (which includes parts, fitting and VAT) that includes the below is much better?

• Complimentary health check including fluid levels, tyre pressure, wash-wipe system, lighting, brakes and more.
• Engine oil and filter change.
• Replacement key fob battery, pollen filter and brake fluid.
• Drive-belt, exhaust line and bonnet catch inspection.
• Headlamp alignment.
• Replacement fuel filter, spark plugs and air filter.

Which obviously includes the required fuel filter (but excludes the MOT charge), and no mention of them looking at the MAF in that price or any gearbox oil change. So maybe that could ramp upto £500+ onwards 
. 
Sigh

General_query

I'd rather Vauxhall did it cheaper if I didn't have the unneeded tyre pressure, wash-wipe system, replacement key fob battery, and bonnet catch inspection, but beggars can't be choosers!

Sorry, waffling on here aren't I?

I'll thank you all again, and see what replies await me in the morning.

General_query

Aaargh, my tired eyes read it wrong. It actually says: Major service for a DIESEL is from £335 
That's me not taking it to Vauxhall now.

Goudy

The juddering and lack of power under heavy load, plus it's mileage might point to an EGR valve problem.

There are obviously a whole host of other possible reasons, but it's a common issue for modern diesels.

The EGR diverts exhaust gases back into the intake and through the engine to try and cool the combustion chambers when the engine is running lean to help reduce NOx. So when you take you foot off the pedal the injectors supply no fuel and the engine will pump air, so gets very hot.

The value will open then to allow exhaust gases back around under these lean conditions as there's little air in it, accelerate and it'll close and only suck in air for the fuel to burn.

If it's failing to close under heavy load it chokes the engine with exhaust gas that lacks the air the engine needs, so you get the judder/shudder and lack of power.

The valve has to cope with some pretty horrid conditions, lots of hot gases and carbon in the exhaust plus modern engines breath out their crankcase pressure into the air intake, which adds a bit of engine oil vapour which all make a toxic mix of sooty gunge that clogs the valve. 

So it's not uncommon for them to suffer a failure after your sort of mileage and the way cars ECU are set up, they don't tend to flag up engine lights for emission related problems until it detects the same fault multiple times in the same drive cycle.

The ECU expects the valve to be open or closed under various conditions (which it monitors against intake pressure), it's it failing to close only under very heavy load, it's only seeing the fault once or twice in a single drive cycle.

Perhaps instead of taking it to Vauxhall, you find a diesel specialist that will be able to log  what the engine is doing under different loads and identify the issue a bit more quickly and cheaply.

BOWFER

daveyjp said:

If the oil has never been changed this may be part of the problem.  Sluggish changes, lack of acceleration can be signs of oil which is turning into treacle.

At ten years old it really is time to change it regardless of any other issues with the car.

Old oil will cause its problems but restricting revs to this degree, not a chance.