5k Kick issues

[TomRS182cup]

I have noticed recently that the 5k kick on my 182 has become much less pronounced than it has been the last 8 months I have owned the car. I have done 11,000 miles in the last 8 months but It had a full service history when i got it, had the cam belt done about 15,000 miles ago and I changed the oil, oil filter and air filter about 4,000 miles ago. Not to mention the car has still only done 33,400 miles at this point.

Any ideas on what could be the problem? it just feels a lot weaker through the revs than it did before. it is still quick but not brilliant.

 

[NickM5c]

You sure you've not just gotten used to it?

 

[J.B.]

Yeah I think you've got used to it. Mechanically there is nothing that makes that '5k kick' so I can't see that anything is wrong. That is unless the car just feels weaker generally?

 

[Chri5]

Could be the weather.....

No really, hot humid days make a car feel underpowered

 

[TomRS182cup]

Yeah I have been talking about how used to the performance of it I am now with my mates recently but I don't think it's just that. My dad has a Trophy which felt a little weak compared to mine. I let him drive mine tonight and he agrees it doesn't feel as strong as it did before. With the extra miles it has done now it has started to develop a fair bit of heat shield rattle too at certain revs, not that that worries me in the slightest.

 

[TomRS182cup]

Yeah I think you've got used to it. Mechanically there is nothing that makes that '5k kick' so I can't see that anything is wrong. That is unless the car just feels weaker generally?

It feels weaker generally throughout the rev range but the kick isn't as noticable either which is strange because as you say there is nothing mechanically that makes the 5k kick. I missed it completely today coming off a roundabout in 2nd, I was still waiting for it until I realised I was at 6,500 rpm

Could be the weather.....

No really, hot humid days make a car feel underpowered

Could just be the weather, it is only the last week or so I have noticed this drop off in power.

 

[Stephenx77]

I remember the first time I felt the 5k kick driving the cup home from the dealer, was going onto a slip road off a roundabout in 2nd gear and I nearly shat myself (previous car was a 1.3 fiesta, so not surprising really lol). But now, although the kicks still there I don't feel it so much because I'm expecting it. Saying that, some days your car just feels faster than it does on other days with no real reason.

 

[Steven103]

it has started to develop a fair bit of heat shield rattle too at certain revs, not that that worries me in the slightest.

Hi,

In my personal experience the (rear) heatshield definitely did not rattle at a certain frequency - only when I went over bumps and shut the boot etc. The rattle that definitely did have a resonant frequency (around 3000 to 3500 RPM - drove me nuts for a week till I found it!) was a loose cat/manifold joint.

The next bit is either something Mr Holmes would be proud of, or a complete waste of time. Renault are supposed to fine tune the shape/length/profile of the entire exhaust system to deliver the exact amount of back pressure for optimum volumetric efficiency. IIRC Chip once explained somewhere that the 5k kick happens because of a large/sudden "blip" in volumetric efficiency (it's normal for volumetric efficiency to change with engine speed, but we all know the F4R is a bit of an odd design!) My thinking being loose cat/manifold joint > blowing exhaust > different back pressure > different volumetric efficiency characteristics > hence 5k kick (which depends entirely on volumetric efficiency) changes in severity.


So yeah, is your cat/mani joint loose lol? £27 for the parts from Renault. Takes about an hour to do on your drive (it's really simple, but there's a high chance of the nuts/bolts being stubborn)

 

[TomRS182cup]

I remember the first time I felt the 5k kick driving the cup home from the dealer, was going onto a slip road off a roundabout in 2nd gear and I nearly shat myself (previous car was a 1.3 fiesta, so not surprising really lol). But now, although the kicks still there I don't feel it so much because I'm expecting it. Saying that, some days your car just feels faster than it does on other days with no real reason.

Haha yeah I had a 1.8 Focus before and even then, the first time the 5k kick hit when I was mid bend I nearly screamed lol

Hi,

In my personal experience the (rear) heatshield definitely did not rattle at a certain frequency - only when I went over bumps and shut the boot etc. The rattle that definitely did have a resonant frequency (around 3000 to 3500 RPM - drove me nuts for a week till I found it!) was a loose cat/manifold joint.

The next bit is either something Mr Holmes would be proud of, or a complete waste of time. Renault are supposed to fine tune the shape/length/profile of the entire exhaust system to deliver the exact amount of back pressure for optimum volumetric efficiency. IIRC Chip once explained somewhere that the 5k kick happens because of a large/sudden "blip" in volumetric efficiency (it's normal for volumetric efficiency to change with engine speed, but we all know the F4R is a bit of an odd design!) My thinking being loose cat/manifold joint > blowing exhaust > different back pressure > different volumetric efficiency characteristics > hence 5k kick (which depends entirely on volumetric efficiency) changes in severity.


So yeah, is your cat/mani joint loose lol? £27 for the parts from Renault. Takes about an hour to do on your drive (it's really simple, but there's a high chance of the nuts/bolts being stubborn)

Thanks for that, that sounds like a brilliant explanation because it did have a slight heat shield rattle on closing the boot from day one but it has developed a fair few more rattles since. I also mentioned to one of my friends recently I thought the exhaust was starting to blow and fart noticeably so this could be exactly what’s going on.

I may have to bite the bullet and buy a new cat back exhaust anyway soon, one of the tail pipes has started to fall lower than the other it’s looking quite rusty and like I say I think it has started to blow.

 

[Steven103]

Ha, your situation sounds like a carbon copy of mine. Fortunately I had one last proper look/feel around the exhaust (with engine being rev'd feeling for exhaust gases) before spending £400 upwards on an exhaust & it turned out to be one simple washer had corroded and let a bolt slip, causing the gasket/seal to fail. This made the exhaust blow, sound rubbish and because the thing was physically loose rattle like crazy around the already mentioned RPM range. Can't comment on a perceived loss of 5k kick etc as I was driving as smoothly as possible to minimise rattling (really did sound like a bag of nails at times)

Also, the rear heatshield is really easy to fix. There's a guide on here somewhere IIRC, but you probably just need one large washer (with a small centre diameter) and a 10mm spanner. Don't even need to jack the car up as it's usually the washer closest to the rear bumper that corrodes (well, strictly speaking the heatshield corrodes but anyway!) so it's relatively easy to reach. Job is made massively quicker with a socket or ratchet spanner though.

 

[stephen chadwick]

i found using 'cheaper fuel' makes it allot less pronounced

 

[TomRS182cup]

Ha, your situation sounds like a carbon copy of mine. Fortunately I had one last proper look/feel around the exhaust (with engine being rev'd feeling for exhaust gases) before spending £400 upwards on an exhaust & it turned out to be one simple washer had corroded and let a bolt slip, causing the gasket/seal to fail. This made the exhaust blow, sound rubbish and because the thing was physically loose rattle like crazy around the already mentioned RPM range. Can't comment on a perceived loss of 5k kick etc as I was driving as smoothly as possible to minimise rattling (really did sound like a bag of nails at times)

Also, the rear heatshield is really easy to fix. There's a guide on here somewhere IIRC, but you probably just need one large washer (with a small centre diameter) and a 10mm spanner. Don't even need to jack the car up as it's usually the washer closest to the rear bumper that corrodes (well, strictly speaking the heatshield corrodes but anyway!) so it's relatively easy to reach. Job is made massively quicker with a socket or ratchet spanner though.

Ha yeah I would much rather find the cause and have a fiddle with it than spend all that money on an exhaust, which is what I will have to do if not. Thanks a lot for your input its been really helpful. I will have a little look at my car this weekend and see if I can't fix it.

i found using 'cheaper fuel' makes it allot less pronounced

That shouldn't be an issue, I have only ever filled the car with V-power, thats over 11,000 miles on V-power, no exceptions. Shell must love me

 

[Steven103]

That shouldn't be an issue, I have only ever filled the car with V-power, thats over 11,000 miles on V-power, no exceptions. Shell must love me

I hear the Shell garage in Fryern Arcade has reopened... (there might be one on the way to your uni, I don't know, just facebook was covered in "Thank God I don't have to go all the way to Portsmouth etc for V Power now" type comments the other day)

 

[Sam]

Is your cat totally standard ?

I think sometimes you just get used to it.

 

[TomRS182cup]

I hear the Shell garage in Fryern Arcade has reopened... (there might be one on the way to your uni, I don't know, just facebook was covered in "Thank God I don't have to go all the way to Portsmouth etc for V Power now" type comments the other day)

Yeah it has, eventually. Shell have been doing a lot of work on their stations recently I think, a lot of them have been closed for a week or three, which means I have to find the next nearest one, sometimes I end up driving miles, but I don't mind:race:

Is your cat totally standard ?

I think sometimes you just get used to it.

The only modification I have done is put an ITG filter in the standard airbox, apart from that it is like the day it rolled off the production line. I may well be far too use to it now. I do find myself driving my favourite roads more or less foot planted these days :quiet: up to 60mph obviously.