Losing power on hills

TopOfTheHill

Hi folks,

I hope this is the right place to ask this, but mods please feel free to move if not.

I have an issue with my '03 skoda superb 1.9 TDi in that it loses its power when going up hills.

I can drive along the flat with no problem, and get up to speeds in excess of 120Km/h.

However, when I reach a hill, it starts to decrease in power. It will go so far up the hill and then feels like something gives, and the power starts to drop. Its like I am pushing air into a sealed container (like a bicycle pump), and then the seal breaks some air puffs out and the power reduces. I feel like a slight tug back as the power drops first and then slowly decreases. I can then maybe reach 60Km/h uphill and thats as far as it will go , even with the pedal to the floor.

When I reach the top of the hill normal service is resumed and speed builds up again - until the next hill, where the process is repeated - maybe without the breaking of the seal this time.

I have had a local mecahnic look at it, and he cannot find the issue - but if anyone has had similar experience so that we have a starting place to look I would appreciate it.

Thank you

Atlantic Dawn

What gear are you in or is it an automatic?

TopOfTheHill

driving in 4th or 5th, but would then have to come down going up the hill

biko

It's not unusual you have to gear down on a steep hill.
Is this a new thing with this particular car and particular hill?

TopOfTheHill

no - its not an issue for coming down the gears, and is a new thing that happens over last 2 months.

I had the turbo replaced abuot18 months ago - so don't think it is that

This is on all hills, especially noticeable on slow climbing hills where the car has sufficient time to slow right down

Especially problematic when going up a hill, and needing to overtake - I do not have the power to speed up and overtake anymore (on a hill) - in the past this was not an issue

To set the scene a bit-
Driving the Cork to Dublin road, driving at 120KM/h no problem, arrive at a hill and start climbing - as the hill progresses the car loses power and drives slower. By top of the hill I am n 4th gear, pedal to the floor driving at 60KM/h - go over the top of the hill and the car takes off again ...

I hope this helps...

Chemical Byrne

Bizarre. I've not heard of that before.
My first thought was a blockage of the low pressure fuel lines in or from the tank that is affected by fuel sloshing back and forth as you transition from the flat to a hill. A car of that age might have a lot of shíte in the tank.
has the fuel filter been changed? might be worth flushing things out?

biko

Possibly the air filter not letting through enough air. Check if it's old and dirty.

keithclancy

Sounds like maybe Air Filter to me as well.

Tony Beetroot

Its very unlikely its dirty air filter.

Chemical Byrne

Perhaps it's down on power all the time but you only notice it going up a hill. Like, it might have enough umph left to keep speed up on the level.

What is acceleration like?

Being an 03, i;d imagine this is a mechanical injection engine?

bazz26

Might be worth having it plugged into a diagnostic computer and see if throws up any fault codes logged on the car's ECU, otherwise you could guessing for a while.

the phantom worker

have had the exact same problem with my 02 a4 1.9tdi. Try cycling the ignition (switch off ignition and back to ACC and then bump starting...can be done on the move provided it is safe to do so) and the power will return....until you get to a little over 120kmh again or you increase the load on the engine by going up the hill.

Car is going into limp mode by the sounds of things. Mine has been to 3 different garages and no resolution. I think the code it was throwing up was an overboost/underboost issue but no one could actually fix the problem.... turbo/intercooler swapped, egr cleaned etc etc

So if anyone has an actual solution to this and not just a temp measure to regain power i'd love to hear it!

OldMrBrennan83

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OldMrBrennan83

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the phantom worker

that was my first port of call when i went to solve the problem myself and couldn't find any but will have another look over the weekend and will let you know if i have any luck! thanks Patww79

OldMrBrennan83

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MeTheMan

Sounds like the car is going into limp mode! I'd get it checked for fault codes.

Turbo causing a car to enter limp mode can be a pain to fix. Could be Air flow meter, vacuum pipes, turbo it's self (But if you replaced that 18 months ago probably not), Actuator arm not moving freely. etc. Reading the code should help narrow down the problem.


The irony of your name!

savagethegoat

what are the RPMs doing?

TopOfTheHill

Thanks for all the replies - I will try a few of the suggestions out and reply with results.

Car was hooked up to a laptop, but because it was stationary there was nothing showing up.

There does not seem to be anything amiss with the RPMs - but that is based on my limited knowledge

Xuro

Either mass air flow sensor dirty or defective or turbo vanes stuck.

Xuro

First try to drive with the MAF disconnected and see if you notice a difference. If you don't then you know the MAF is either broken or dirty and I would take it out and clean it carefully. Look it up on youtube there are many videos out there.

MeTheMan

It doesn't matter the car is stationary. You need to get it scanned with VCDS/Vag-com or similar software. If the car is entering limp mode it will throw an error. This will be stored on the cars computer for reading later.

If there is no codes showing when scanned I would guess the car isn't entering limp mode.
After you get over the hill do you notice the car is still down on power? You can feel the pull of the turbo at around 2000 RPM.

TopOfTheHill

So, finally got around to having this fixed :eek:

And on the off chance that some unlucky driver comes across this thread with a similar problem...

The problem turned out to be with a sensor that regulates the vacuum to the turbo. This has been replaced, and all is good again.

Thanks for all the assistance.