Fiesta St500 Mk6 Hunting/rev Limiter Issue

[BrynC1994]

Hi Guys,

noticed lately when sitting still with the engine running the engine is hunting a little, I mean not a huge amount about 100rpm max either way of around 900rpm and it not like constantly a 100rpm it moves its just constantly up and down by varying degrees and I was just wondering if this is normal? the other thing I have noticed is that it isn't bouncing of the rev limiter like I think it should, the other day being a bit of showoff I did a bit of a burnout for my mates and had it bouncing off the rev limiter like ba,ba,ba,ba,ba,ba,ba,ba we all know the sound, but recently I revved it out of interest because I noticed the hunting and when it hit the rev limiter it over revved then dropped revs, paused then over revved again with about a second between each over rev like vrooooom...............vrooooom.........vroooom and so on with my foot to the floor the whole time rather than the usual ba,ba,ba,ba,ba,ba am I being stupid here or is this something I should investigate further? and just a minor question under heavy breaking from high speeds is it a safety feature that the hazards start flashing till I let off the brakes?

thanks in advance for you help.

Bryn

[D13 HPD 95]

i know the hazards flashing under heavy breaking is a feature is nearly all cars now so that normal but i have now idea about the others, unless its the throttle valve I'm sure someone will be able to help

[BrynC1994]

Aha cheers buddy I was quite shocked to see it for the first time because I was overtaking someone slow to get through the green traffic lights at the cross roads near me and they went yellow and I was closish so I hit the anchors and the hazards started flashing I was worried I had broken something haha

[D13 HPD 95]

naaa its normal m8

[Nathan_M]

The hunting only sounds like a slight tumble which for a modern car is almost inevitable as it trys to run as slowly as possible at idle, if its a sort of vibrating tumble where the car shakes a bit then its struggling a little but i wouldn't worry it doesn't sound like anything, as for the limiter, its electronic so when you rev the car at idle its not going to bounce off the limiter as it hasn't got anything to force it up there, when the wheels were turning they would push the revs straight up above the threshold if you like so it cant not bounce of the limiter, if you dipped the clutch it would do the same thing as mentioned at a stand still, i wouldn't make it a habit of running it right up the limiter as its just not good practice, its similar to chasing someone around who is much less fit than you 1 its not fair and 2 it doesn't do him any good.

[BrynC1994]

Hahaha I liked your last line! But brilliant it's good to know! Glad i was worrying about nothing haven't go any money left this month after doing the clutch! Aha