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

General_query

Hello,
I have been having a problem with our Vauxhall Meriva B 1.7 Diesel (automatic) in that when attempting to overtake an HGV or other slower moving vehicle on the motorway, the car seems to draw level with the vehicle then refuses to accelerate enough to be able to safely overtake the other vehicle then safely pull back in front. It started between 70-80mph on motorways and judders in what I call a "kangaroo state" and this sounds weird but I can "feel it" trying to get into a higher gear to give more power, even though its an automatic. So, I have to abandon the manoever and pull back behind the vehicle, both embarrassed by the fact I couldn't overtake as my car "couldn't handle it" and also worried as to what's up with it?
It's the same on an incline, for example coming up a gradient. Accelerates nicely then seems to "stick" and won't go faster then starts the dreaded "judder" before slowing down.
Haven't used the car much due to lockdown, but it's now started happening at like 60-70mph, no problem with lower speeds, just anything above 60mph now.
No warning lights on dashboard or anything. Passes its MOT every year and is serviced in March every year (due soon).
I think the "rev counter" seems to stick at 2500 when it behaves like this and refuses to change gear / accelerate, whereas I think I'm right in saying, the rev counter increases (then decreases after a gear change) while driving as the car gets faster? Yes I know nothing technical like cars etc, just being as honest as descriptive as I can.

Means nothing to me but have googled it and suggestions include:

Faulty Mass Airflow Sensor - As you go down the road, you’ll feel your Meriva really jerk and hesitate as the engine speed changes erratically.  It’s bad for your motor mounts when this happens.  

Opel Meriva: Bad Coil Packs - Bad Coil Packs are one of the more problematic ignition issues that can occur with the Opel Meriva.  A bad oil pack can make your Meriva almost un-drivable.  Or it may have little effect at all on the engine’s ability to run.  It’ll get worse as they lose their ability to fire the spark plugs.

As you hit your Meriva’s gas pedal, the fuel and ignition systems respond.  If acceleration has diminished, it should be felt.  The less cylinders that your engine has, the more that one cylinder not firing properly will have an effect on engine performance. If you have one or more bad Coil Packs, it’ll cause the acceleration of the Meriva to be weaker, and you’ll probably feel a jerking sensation.

(sorry for the crude cut and paste).
Any help please? Like I said, there are no dashboard error codes and it doesn't make any weird loud noises or anything when driving, just this refusal to accelerate any further and the worrrying "jerking movemment" while trying to overtake between 70-80mph, well now anything above 60mph.

Thank you.

BOWFER

As it's a diesel, you can discount the coil packs - it doesn't have spark plugs and therefore doesn't have coil packs.
The MAF is a possibility, it has one of those.

General_query

Thanks, just Googled that and you're right, they don't have spark plugs - but do have something called glow plugs (like I know what they are!).
There's no thick, black smoke while starting, or driving and no issues with it starting up, just this loss of power and the juddering...

General_query

(darn edit facility).... the juddering at "high" speeds

AdrianC

When was the fuel filter last changed?

jimjames

MAF or turbo getting clogged so it goes into limp mode? I know that's an issue with VAG but not sure about Vauxhall.

General_query

AdrianC said:

When was the fuel filter last changed?

Last serviced on 20th March 2020:

Oil
Oil Filter
Air Filter
Cabin Filter
2x tyres

Is the Oil Filter the same as a fuel filter? 

AdrianC

General_query said:

AdrianC said:

When was the fuel filter last changed?

Last serviced on 20th March 2020:

Oil
Oil Filter
Air Filter
Cabin Filter
2x tyres

Is the Oil Filter the same as a fuel filter? 

No. An oil filter filters the engine oil. A fuel filter filters the fuel.

If you don't know when the fuel filter was last changed, change it. Quick, easy, cheap. Probably less than a tenner for the part.

If it starts to get blocked, it won't let as much fuel through - so, when you need most fuel, you may find it's simply not being delivered. That would fit with your symptoms. Behaves just fine except when you're needing most fuel, then it staggers...

General_query

Well there's no chance of me doing it if I have to get under my car, sorry I'm just not that competant.

daveyjp

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

Mickey666

General_query said:

Thanks, just Googled that and you're right, they don't have spark plugs - but do have something called glow plugs (like I know what they are!).
There's no thick, black smoke while starting, or driving and no issues with it starting up, just this loss of power and the juddering...

Diesels have glow plugs to help with cold starting but they are not used once the engine is running, so they won't be the cause of this problem.