Hi
I have a problem with my Fiat Palio.
When I drive at a speed of about 90km, the car starts to shake alot.
It almost feels like a flat tyre!
When I let go of the petrol, it's better.
When it idles it also sounds like the spark plugs miss.
I replaced the spark plugs,but it's still not better.
What can be wrong?

check the bolts are done up properly and try getting your wheels balanced. this is usually the main cause for shaking, it's always good to eliminate first as well as it's cheap to do.

I did my wheel alignment. And the car runs smooth if I let go the petrol. Is there a possibility that it can be the spark plug cables? And what does spark plug cables cost in South Africa?

www.magnecor.co.uk

One of the best cables, and they ship worldwide.

Rheta,

I would not read too much into the car misfiring occasionally on idle, since that is quite common in Palios (though I would not go so far as to say that it should be considered 'Normal' or 'OK').

If the car seems to shake at speed (but the steering wheel does NOT vibrate at the same time), I would suspect unbalanced/bent Rear wheels. if the steering wheel also shakes at the same time, the problem is most likely with the front wheels.

Misfiring (at idle) will destroy the catalist in no time, so it is absolutely NOT common on any modern Fiat engine.

Oops! I meant 'missing' not 'misfiring'. Mea culpa!

What's the difference..??
Misfiring, or missing, at idle (or in fact at any rpm), will let unburnt fuel into the hot catalyst, this unburnt fuel can ignite inside the catalyst, and will destroy it soon.
So misfiring or missing is a very dangerous situation for a modern engine, and is by no means to be considered as "normal".
Worn or wrong sparkplugs, sparkplug leads, or defective Bobine's ( and many other conditions) can cause misfiring (or missing) and should be replaced as soon as possible...!
Btw, I use Bosch +4 plugs in my 1,6-16V Palio engine, the Bosch +4 has four way's for the spark to follow, misfiring is brought back to a minimum this way.

Thank you for all the feedback, it seems there were bearings missing in the CV somewhere that caused the shaking, but the car is still missing, will check the spark plugs again!
Thanks!!

Hi Rheta,

I suggest that one night you let the car idle with the bonnet open. It must be in complete darkness. Then spray a fine mist of water over the plug leads. If you see some sparking or fine "lightning like" flashing, you will know it is your leads.

When last has your car been for a tune-up? It may just need some TLC