Vauxhall Astra Mk4 - occasional problem

pinkteapot

Just wondering if anyone has any ideas/advice.

Vauxhall Astra Mk4 52-plate 1.6l 8v.

Yesterday I was on the M25 in one of the 50-limit roadworks sections. Traffic was heavy so our speed dropped to about 45mph and I dropped from 5th gear to 4th. Poodled along in 4th for a bit then the car started sort of jerking. That spluttery pulling sensation you get when it's about to stall. This was in 4th gear at a steady 2,500 RPM. I tried putting the clutch down planning to re-engage the gear but with the clutch down all three warning lights (oil, battery, EMS) came on. Quickly let go of the clutch and it carried on in 4th, still jerking. I changed down to 3rd and it was fine. Revving at 4,500 so not ideal but running fine. Changed back up to 4th and it started lurching again. Up to 5th and it was obviously revving too low to be happy but didn't jerk.

Weird thing is that EXACTLY the same thing happened last summer, also in a 50 limit on a motorway where the traffic speed dropped so I dropped gear to 4th.

It's such an intermittent fault (once every 6 months) that I'm not convinced the garage would find anything. My brother says it's the result of iffy fuel and his Vauxhall Vivaro van does it occasionally. Surely a bit of bad fuel going through would affect it regardless of the gear though.

Any tips? I was scared it would conk out in heavy traffic so I drove in 3rd till we were out of the 50-limit, figuring revving high in 3rd would be less bad for the engine than revving low in 5th.

No problems with the car aside from this. (It did have a stall-and-wouldn't-restart issue a few months back but that was from a standing start at a junction; don't think it's related).

johnnyroper

The 16szr fitted to your astra does suffer from a couple of issues that could potentially give a fault with jerking at 2500 rpm.

Firstly a sticky egr valve
Secondly they used to have inlet manifold gaskets that cracked.

With those 3 lights coming on it is a bit strange for all to come on together,I would have a check of battery connections,earth points and charge rate.

pinkteapot

Thanks, I've been googling and the EGR valve seems to be mentioned a lot in relation to similar problems. When we got the car three years ago the engine management light came on a couple of times and an EGR valve fault code had been logged. I can't remember how it was fixed at the time - whether the valve was replaced or not. In any event we've down 20k miles since then.

What's a 16szr? I'm not a car techie.

Re the three lights, I put the clutch down and the oil light came on first, followed a second or two later by the other two lights. They went off when I released the clutch.

It's a very occasional problem but it's unsettling when it happens. Conking out in heavy motorway traffic would not be fun! A family friend runs a garage so I've booked the car in for him to take a look next week. I figured having to change gear and drive in the wrong gear probably wasn't a good ongoing solution.

Oscar (that's the car!) is taking us from Essex to the Orkney Islands in June so I want him in good working order for that!

Gordon_Hose

x16szr relates to the type of engine you have.

X = Euro 2 emission regs

16 = it's a 1.6

S = 9.5 to 10:1 compression ratio

Z = single-point injection fuelling

R = increase output

johnnyroper

pinkteapot wrote: »

Thanks, I've been googling and the EGR valve seems to be mentioned a lot in relation to similar problems. When we got the car three years ago the engine management light came on a couple of times and an EGR valve fault code had been logged. I can't remember how it was fixed at the time - whether the valve was replaced or not. In any event we've down 20k miles since then.

What's a 16szr? I'm not a car techie.

Re the three lights, I put the clutch down and the oil light came on first, followed a second or two later by the other two lights. They went off when I released the clutch.

It's a very occasional problem but it's unsettling when it happens. Conking out in heavy motorway traffic would not be fun! A family friend runs a garage so I've booked the car in for him to take a look next week. I figured having to change gear and drive in the wrong gear probably wasn't a good ongoing solution.

Oscar (that's the car!) is taking us from Essex to the Orkney Islands in June so I want him in good working order for that!

i would say egr is problem you are having,after reading through post again i suspect the engine has stalled when depressing clutch causing lights to come on but when releasing clutch the engine started again.

x16szr is the engine code.