astra mk4/g jerking problem

superman1777

Hello
I have a 2001 (Y) Vauxhall astra 1.6 8v

I purchased this car around 11 months ago
Brief history
Full service history
Has just had major service and MOT120000 miles on 5th August
So all filters changed levels topped up etc
Had to have a new complete exhaust fitted at service and a metal drivers side brake pipe replaced
On 15 the August the battery was replaced with brand new one
On 12th August EGR valve replaced new as it has stopped working.

The car has been near perfect for age and drives well

Today as I was travelling along the motorway at around 70mph I accelerated to overtake and there was a noticible jerk/jolt as if the car was about to stall. Without doing anything different with my feet the car just went from 75 to 60 and felt like it had lost all power the speedo was going crazy back between 75 - 60 this was for less than 1 second. So I slowed down to 60 in slow lane and the car seemed to travel without issue until I accelerate to overtake again and same problem..

So I pulled into services and opened bonnet. All battery terminals are tight and everything seemed OK..

Even checked oil - this was fine

There was half tank of petrol so not low fuel

I managed to get home. About 25 miles without this problem happening again.

Seems to be intermittent

Hmmm..... Any ideas/help appreciated

Thanks

EdGasket

Change the spark plugs; maybe one or more is no longer firing under load i.e. when trying to accelerate in top gear. That would cause it.

roneik

Possibly fuel filter or/coil pack / or plugs or leads going west

roneik

On reflection plugs would probably cause misfire and loss of power, even one. If it was not intermittent you could remove lead one at a time to check if engine tone was altering. As you have an intermittent problem I would go fuel filter or pump. Possibly coil pack
Cant you get a readout of the fault from a garage?

superman1777

I will ring garage in morning and get it booked in , explaining the problem.....

As mentioned it did have a major service and MOT on 5th August but there is no mention/charge for replacing spark plugs.
Considering it has done 120000 miles shouldn't the plugs have been changed at service ?

roneik

Just to let you know

• A significant drop in RPMs while accelerating for no apparent reason

This is just one symptom of a failing coil pack. Some cars have one coil pack serving all cylinders, others have individual coil pack for each cylinder. When they get advanced problems you sometimes get a backfire of on burnt fuel Or misfiring. I would start there and if no cure, change leads and plugs. If still the same go for fuel filter and last fuel pump test or replace

roneik

Plugs vary , some have platinum tips and can be good for 30/50k

facade

Crankshaft position sensor?

They rarely if ever put the EML on, but put the car in limp mode. They start failing when hot, and are fine when the engine cools down, until the next long fast run.

roneik

I have never owned a astra so my knowledge of them is limited to what I know generally. The last poster may well have hit the nail with crankshaft sensor. My money is on coil pack failing (early stages)

Edit to add . coil pack replaces the old distributors and in conjunction with engine management chip does the same job
Those were the days distributor and a strobe light and blobs of paint to determine timing

maninthestreet

Check the distributor cap for tracking.

EdGasket

superman1777 wrote: »

I will ring garage in morning and get it booked in , explaining the problem.....

As mentioned it did have a major service and MOT on 5th August but there is no mention/charge for replacing spark plugs.
Considering it has done 120000 miles shouldn't the plugs have been changed at service ?

If you are sending it to the garage anyway, it's rather a waste of our time trying to help you.

Spark plugs can become oil fouled and fail to spark under load.