Test driving a car for power on an empty tank?

Jlawson118

I'm sure some of you will recall my threads regarding a lack of power in my car and a dealership refusing to help me out, although I don't want this one to be merged with the other, this is a different matter to me.

Anyway, so for those who haven't seen my previous threads, I'm suffering lack of power with my car and I've had it diagnosed by an independent mechanic that my timing chain is stretched and is in need of a replacement. I have a year's warranty with the main dealers but they're refusing to accept the timing chain fault.

But they invited me in yesterday where the service manager test drove my car, going at a speed where he didn't have to lift the clutch up all that fast on gear changes so he didn't witness the jerky motion I do when changing when I have to set off at quite fast speeds and over-rev. But then after that, he got a 'like for like' car for me to test drive that they had for sale, same engine spec, similar mileage but two years younger than mine. At first the car seemed smooth, but the fuel light was flashing and the needle on the fuel gauge was actually on 0, right at the bottom.
I don't know how that car was moving whatsoever. We called in at a petrol station and he put a fiver in it, and the journey back was up hill, the car was struggling quite a lot, made my car and it's problems feel like driving a sports car.

I don't know much about how cars run, but I can assume giving the car £5 was like giving somebody who's dehydrated a teaspoon full of water and then expect them to go straight away. I can imagine the car was running solely on the dirt at the bottom of the tank.

Is this really a biased review? He claimed the lack of power is how they all are, but I feel like that one would have run quite nicely with even just a quarter of fuel in the tank, half, or even full. But the needle was on 0!

AdrianC

Jlawson118 wrote: »

But they invited me in yesterday where the service manager test drove my car, going at a speed where he didn't have to lift the clutch up all that fast on gear changes so he didn't witness the jerky motion I do when changing when I have to set off at quite fast speeds and over-rev.

Mmm.

At first the car seemed smooth, but the fuel light was flashing and the needle on the fuel gauge was actually on 0, right at the bottom.
I don't know how that car was moving whatsoever.

Because it still had some fuel in. Enough fuel. A litre of fuel is, what, about ten miles? So one mile is 100ml - a third of a can of coke. How accurate do you think that fuel gauge is, when full is probably 60 litres or so?

I don't know much about how cars run

I don't want to seem patronising, but it shows.

but I can assume giving the car £5 was like giving somebody who's dehydrated a teaspoon full of water and then expect them to go straight away.

Nope. The engine takes very precise - and tiny - amounts of fuel, pressurised. So long as there's some fuel in the tank, there's enough for it to drive perfectly normally. When it runs out, it runs out. Did it actually run out? No.

I can imagine the car was running solely on the dirt at the bottom of the tank.

The fuel is always taken from the same place in the bottom of the tank, and it's filtered before entering the engine.

angrycrow

If your car drove fine for the dealer then it suggests your driving style may need to be adjusted. For example changing up gear too early and then taking a long time to change can allow the car to drop out of its power band and then bog down in the higher gear.

A car with very little fuel in will always feel more nimble due to reduced weight. The car will generate the same performance with low fuel level right up to the point it runs out and stutters to a stop.

I cant remember what engine you said you had so I will assume 1.2 petrol. This is fine for around town but on open roads up hill you will may need to drop a gear to keep the same speed

k3lvc

OP - having read this and your previous threads you seem to have some expectations of this car which it's not delivering for you. What seems to be happening now is that you're not listening to what the dealer's telling you irrespective of whether they're playing you or being honest with you

There's a couple of ways you're going to get out of this cycle

1) Cut your losses, sell the car and buy a new one from somewhere different (after a long test drive) - suspect you may be back on here asking similar questions again though

2) Find a trusted (older) friend who knows about cars and can help you work out whether it's you or the car that's wrong and then work on a solution from there

forgotmyname

Jlawson118 wrote: »

I'm sure some of you will recall my threads regarding a lack of power in my car and a dealership refusing to help me out, although I don't want this one to be merged with the other, this is a different matter to me.

Anyway, so for those who haven't seen my previous threads, I'm suffering lack of power with my car and I've had it diagnosed by an independent mechanic that my timing chain is stretched and is in need of a replacement. I have a year's warranty with the main dealers but they're refusing to accept the timing chain fault.

But they invited me in yesterday where the service manager test drove my car, going at a speed where he didn't have to lift the clutch up all that fast on gear changes so he didn't witness the jerky motion I do when changing when I have to set off at quite fast speeds and over-rev. But then after that, he got a 'like for like' car for me to test drive that they had for sale, same engine spec, similar mileage but two years younger than mine. At first the car seemed smooth, but the fuel light was flashing and the needle on the fuel gauge was actually on 0, right at the bottom.
I don't know how that car was moving whatsoever. We called in at a petrol station and he put a fiver in it, and the journey back was up hill, the car was struggling quite a lot, made my car and it's problems feel like driving a sports car.

I don't know much about how cars run, but I can assume giving the car £5 was like giving somebody who's dehydrated a teaspoon full of water and then expect them to go straight away. I can imagine the car was running solely on the dirt at the bottom of the tank.

Is this really a biased review? He claimed the lack of power is how they all are, but I feel like that one would have run quite nicely with even just a quarter of fuel in the tank, half, or even full. But the needle was on 0!

A mate said he had his car was low on fuel showing right on the empty line, and the trip computer said zero miles left.. He did 37 miles after it went to zero.

And re:timing chain. You/He have not diagnosed it as a stretched timing chain. Its a best guess with the symptoms you claim to have. He has not removed and checked the timing chain, so cannot say for certain if that is the problem.

cajef

Jlawson118 wrote: »

so he didn't witness the jerky motion I do when changing when I have to set off at quite fast speeds and over-rev.

I don't know much about how cars run,

Probably because he was driving with the correct engine revs before changing gear, I am not surprised you are having jerky motion if that is your driving style.

Your last statement says a lot.

Mobeer

Jlawson118 wrote: »

...I'm suffering lack of power with my car and I've had it diagnosed by an independent mechanic that my timing chain is stretched and is in need of a replacement.

There is no indication of cause and effect in this - nothing to say there is a lack of power due to the timing chain issue.

Jlawson118 wrote: »

I have a year's warranty with the main dealers but they're refusing to accept the timing chain fault.

Have they said why? Perhaps they consider this a wear and tear issue, depending upon the age of the car.

Jlawson118 wrote: »

But they invited me in yesterday where the service manager test drove my car, going at a speed where he didn't have to lift the clutch up all that fast on gear changes so he didn't witness the jerky motion I do when changing when I have to set off at quite fast speeds and over-rev.

If you "over-rev" then perhaps this is a cause of the jerkiness. If the jerky motion only occurs when you are driving then it probably isn't a car issue.

Jlawson118 wrote: »

But then after that, he got a 'like for like' car for me to test drive that they had for sale, same engine spec, similar mileage but two years younger than mine. At first the car seemed smooth, but the fuel light was flashing and the needle on the fuel gauge was actually on 0, right at the bottom.
I don't know how that car was moving whatsoever. We called in at a petrol station and he put a fiver in it, and the journey back was up hill, the car was struggling quite a lot, made my car and it's problems feel like driving a sports car.

Most dealers keep their cars near empty. It prevents anyone trying to steal fuel out of them, means any stolen car can't go far without appearing at a fuel garage (on CCTV), and it means cars can be sold without costing the dealer any fuel.

Jlawson118 wrote: »

I don't know much about how cars run, but I can assume giving the car £5 was like giving somebody who's dehydrated a teaspoon full of water and then expect them to go straight away. I can imagine the car was running solely on the dirt at the bottom of the tank.

Just because a car is near empty doesn't mean it is completely empty.

Jlawson118 wrote: »

Is this really a biased review? He claimed the lack of power is how they all are, but I feel like that one would have run quite nicely with even just a quarter of fuel in the tank, half, or even full. But the needle was on 0!

From what I have seen of your previous posts, the car is a Vauxhall Corsa? These typically aren't high performance cars (with a few exceptions). Are you sure you don't just have unreasonable expectations of how fast your car should be?

Jlawson118

k3lvc wrote: »

OP - having read this and your previous threads you seem to have some expectations of this car which it's not delivering for you. What seems to be happening now is that you're not listening to what the dealer's telling you irrespective of whether they're playing you or being honest with you

There's a couple of ways you're going to get out of this cycle

1) Cut your losses, sell the car and buy a new one from somewhere different (after a long test drive) - suspect you may be back on here asking similar questions again though

2) Find a trusted (older) friend who knows about cars and can help you work out whether it's you or the car that's wrong and then work on a solution from there

I just know that the car didn't drive like it did when I first got it. I've had second, third and even fourth opinions that all state I need a new timing chain and everything will be back to normal

Jlawson118

cajef wrote: »

Probably because he was driving with the correct engine revs before changing gear, I am not surprised you are having jerky motion if that is your driving style.

Your last statement says a lot.

Yeah he was driving on 20mph limit roads around the dealership, a lot of revs aren't required and motion was normal. However, when I'm required to set off from traffic lights in a 40mph zone or I'm driving out of a lane and merging onto a road, the car just doesn't want to move. That's the issue I'm having here. I was nearly hit badly by a truck a few weeks ago coming out of a road a few weeks ago and I moved out with plenty of time but the delay meant I was coming out too late. That's the issue I'm having here

AdrianC

Jlawson118 wrote: »

However, when I'm required to set off from traffic lights in a 40mph zone or I'm driving out of a lane and merging onto a road, the car just doesn't want to move. That's the issue I'm having here. I was nearly hit badly by a truck a few weeks ago coming out of a road a few weeks ago and I moved out with plenty of time but the delay meant I was coming out too late. That's the issue I'm having here

Do you have a dashcam? Any way of using your phone as one?

forgotmyname

Jlawson118 wrote: »

I just know that the car didn't drive like it did when I first got it. I've had second, third and even fourth opinions that all state I need a new timing chain and everything will be back to normal

So 4 opinions and not one PROPER report with evidence. Maybe you should be looking at buying an M3 instead?