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Vauxhall corsa acceleration VERY slow, car struggles to reach 70mph and cant go over 30 uphill

my car struggles to reach 70mph, to the point where uphill on a motorway i come to like 30mph. also it has terrible acceleration where i struggle to get out onto roundabouts and sometimes when i start the car it doesnt start first time and the second time it takes like 5-8 seconds to turn over. it only has 65000 and its a 3 cylinder 1.0L vauxhall corsa. im going to replace the spark plugs tomorrow as i was thinking thats what it would be but im not sure. im trying to save as much money as possible and it is my first car i dont want to have to scrap it and save up for a new one. help would be greatly appreciated. thanks. sorry for being so long.

Getting the car up to date with maintenance is a good first step, and that likely includes replacing the air filter and the fuel filter, in addition to the spark plugs. That may cure the condition, although I tend to think that it won’t.

The symptoms that you describe are more likely to be the result of a weak/failing fuel pump, or–possibly–a clogged catalytic converter. If it turns out to be the fuel pump, a possible cause of the condition was failure to replace the fuel filter on schedule.

You didn’t mention anything about the Check Engine Light being lit up, so I am assuming that this is not the case, but just in case you neglected to mention that very important detail, you need to have the stored trouble codes read. Otherwise, you could wind up just throwing parts at the problem–at random–and that is more expensive in the long run.

Just curious as to what year this is.

I also think you have an exhaust blockage. A clogged or collapsed catalytic converter is a likely suspect, but a collapsed muffler or silencer can also make this happen. A foreign object jammed in the tail pipe can also do this.

The long cranking times before starting sounds like a fuel problem

But the other stuff sounds like it could also be a restricted exhaust

Since this is a Vauxhall, I am assuming the car is in the UK, Australia or New Zealand. Does the car even have a check engine light, or does it have a symbol of an engine instead?

if the check engine light is on, are there possibilities for getting codes read for free?

By all means, get the maintenance stuff up to date, before scratching your head and paying for expensive parts/diagnosis

My car is a 2004 model from the uk. There is no lights on my dashboard atall. Reading some stuff online has me thinking it might be something as simple as a faulty spark plug. I am going to buy and replace all 3(3 cylinder engine) myself tomorrow and I will give you guys an update if this has helped or not. There is a few things wrong with my car that I also plan to get fixed but I’m just starting off with the higher priority things first.

Another thing I forgot to mention was that when I put my foot on the gas halfway is when I get my maximum speed out of each gear. If I push any further towards the floor there is no difference in speed


I recommend to install exactly those plugs listed in the owner’s manual. The exact brand and model

You probably have coil on plug ignition . . . one coil per plug, yes?

If your engine uses wires, I’d go ahead and replace those, as well

By the way, does your car have a separate fuel filter, or is it part of the fuel sender assembly, in the tank?

I’m not too sure about cars as this is my first one but I know there is one wire that goes in the side of the bit that needs to be disconnected from the spark plugs. This is a link to the same car as mine getting spark plugs replaced of this helps.

If this sluggishness is general in nature and the engine is not bucking or jerking at idle or during acceleration I tend to agree there could be a clogged converter problem.
Another possibility is a faulty MAF sensor.

If the plugs are the originals then they should be replaced but I’m not so sure that’s the cause of the anemic engine.

I’m also assuming here that while the engine is low miles it hasn’t been cooked from overheating or lack of oil changes. With the plugs out a compression test would be a good idea; just in case.


Nice video you found there

In regards to that coil pack, if those 3 boots are available, and not outrageously expensive, I’d consider replacing them

Sure sounds like a clogged cat. Next would be fuel pump.

“Another thing I forgot to mention was that when I put my foot on the gas halfway is when I get my maximum speed out of each gear. If I push any further towards the floor there is no difference in speed”

This is also consistent with a plugged cat. The restriction means that once you reach “half throttle” the exhaust system can’t handle any more exhaust flow, so pressing the accelerator any further doesn’t produce any more power.

Update: fitted my new spark plugs and I had to get a real wheel hub and bearings fitted. This car is costing me so much to drive. Struggling to get by with it falling apart a lot. How much will a cat cost or would I be better getting a new car

Finally got to driving the car again tonight after the spark plugs were fixed. Car is still the same with the exception of the car starting a little more smoothly. I’ll upload a video and link it on here so you guys can get a little more detail to help me.( help so far has been extremely appreciated thank you guys) I’ll put the video on tomorrow then I’ll go from there. Think the next step is to get a completely new exhaust system along with the new CAT. Hopefully the video tomorrow helps so I ain’t just throwing money at my car.

Can you un bolt the cat and see if it helps?

Cost for a cat depends on where you are. Here in the States a new cat would be maybe a few hundred dollars if you did it on the cheap. Even if it’s more expensive there, the car is still relatively low miles. I would replace the cat instead of getting rid of the car.

I live in the uk. And I don’t have much tools and the know how to take apart the CAT convertor sorry. I think I’ll take it to a exhaust garage in the next few days and see what they think and get a rough price

Don’t know if this is the correct part, but the price of £110 sounds right…

Looks like the cat is integral with the exhaust manifold. You just bolt it onto the engine. But you’ll need the shop to do it for you.


When you take the car to the shop, pay them for a diagnosis. They’ll probably use a scan tool, vacuum gauge, and/or a backpressure tester. Maybe all 3

I’d hate for you to pay them to do the cat, and then the problem was actually something else