Juddering at low RPM...

[General Madness]

Hi all,

I have a PH2 172, I was out driving yesterday and covered maybe 30 odd miles. I returned home for a short while and parked up.

When I returned to the car after an hour or so, It started fine but when pulling from around 1200-1800 RPM in either 1st or 2nd it had some sort of juddering effect. I have no idea what may be causing this but to me there is a slight difference in the noise from the exhaust, kind of sounds like to much back pressure. Could be talking pish though.

It has behaved the same this morning but only when it got up to temp.

I have checked to make sure coil pack and leads are connected... That is the extent of my knowledge on the matter.

Anyone have any bright ideas?

Cheers

Dave

[littleredrooster]

You probably have a coil pack breaking down. Diagnostics will tell you which one. What's a PH2 172?

EDIT to add: Get it fixed sharpish or it will poison your cat.

[jimbobsimmonds]

Had a similar thing in my dad's car when a coil was on its way out...

Didn't have a similar warning when a coil pack in mine failed at WOT in 4th (brown trouser moment...)

[General Madness]

littleredrooster said:

You probably have a coil pack breaking down. Diagnostics will tell you which one. What's a PH2 172?

EDIT to add: Get it fixed sharpish or it will poison your cat.

A Renault Sport Clio 172 Phase 2.

I had a suspicion that this was the case, Im not sure if it has ! main coil or individual ones.
Any idea?

[General Madness]

jimbobsimmonds said:

Had a similar thing in my dad's car when a coil was on its way out...

Didn't have a similar warning when a coil pack in mine failed at WOT in 4th (brown trouser moment...)

Thank you. It seems to be quite a common thing.

[Papa Hotel]

General Madness said:

littleredrooster said:

You probably have a coil pack breaking down. Diagnostics will tell you which one. What's a PH2 172?

EDIT to add: Get it fixed sharpish or it will poison your cat.

A Renault Sport Clio 172 Phase 2.

I had a suspicion that this was the case, Im not sure if it has ! main coil or individual ones.
Any idea?

Startlingly good guess at a diagnosis there from littleredrooster without even knowing the car. Coil pack failure is not a rare issue with these.

[General Madness]

Papa Hotel said:

General Madness said:

littleredrooster said:

You probably have a coil pack breaking down. Diagnostics will tell you which one. What's a PH2 172?

EDIT to add: Get it fixed sharpish or it will poison your cat.

A Renault Sport Clio 172 Phase 2.

I had a suspicion that this was the case, Im not sure if it has ! main coil or individual ones.
Any idea?

Startlingly good guess at a diagnosis there from littleredrooster without even knowing the car. Coil pack failure is not a rare issue with these.

Haha, I thought that also.
Pure genius!

[littleredrooster]

General Madness said:

Papa Hotel said:

General Madness said:

littleredrooster said:

You probably have a coil pack breaking down. Diagnostics will tell you which one. What's a PH2 172?

EDIT to add: Get it fixed sharpish or it will poison your cat.

A Renault Sport Clio 172 Phase 2.

I had a suspicion that this was the case, Im not sure if it has ! main coil or individual ones.
Any idea?

Startlingly good guess at a diagnosis there from littleredrooster without even knowing the car. Coil pack failure is not a rare issue with these.

Haha, I thought that also.
Pure genius!

Doesn't matter what car it is - juddering at low revs is an indication of having a cylinder off. Electrical gremlins account for the majority of misfires, so likely diagnosis is a coil or associated bits. Elementary stuff - it wasn't a guess.

I'm an engineer, BTW, and have been diagnosing and generally meddling for 40-odd years...

[General Madness]

littleredrooster said:

General Madness said:

Papa Hotel said:

General Madness said:

littleredrooster said:

You probably have a coil pack breaking down. Diagnostics will tell you which one. What's a PH2 172?

EDIT to add: Get it fixed sharpish or it will poison your cat.

A Renault Sport Clio 172 Phase 2.

I had a suspicion that this was the case, Im not sure if it has ! main coil or individual ones.
Any idea?

Startlingly good guess at a diagnosis there from littleredrooster without even knowing the car. Coil pack failure is not a rare issue with these.

Haha, I thought that also.
Pure genius!

Doesn't matter what car it is - juddering at low revs is an indication of having a cylinder off. Electrical gremlins account for the majority of misfires, so likely diagnosis is a coil or associated bits. Elementary stuff - it wasn't a guess.

I'm an engineer, BTW, and have been diagnosing and generally meddling for 40-odd years...

Cheers for your advice, Its appreciated.

I noticed though that this morning it did not do it when cold, only once the engine had a bit of heat in it. Does this ring true with what you say?

[NateWM]

Is this happening when on the biting point or did you mean the clutch is fully engaged and you are just pulling from low revs?

It could be clutch judder. My Honda does the same.

[littleredrooster]

General Madness said:

Cheers for your advice, Its appreciated.

I noticed though that this morning it did not do it when cold, only once the engine had a bit of heat in it. Does this ring true with what you say?

Yup - typically they break down when hot. Crank sensors can do this also - work when cold, go on strike when hot. (That's not your issue, however, as it would stop the engine altogether).

[General Madness]

NateWM said:

Is this happening when on the biting point or did you mean the clutch is fully engaged and you are just pulling from low revs?

It could be clutch judder. My Honda does the same.

It happens when the clutch is engaged. second gear pulling from 1000-2000 rpm there is juddering between 1200-1800.

Cheers

[General Madness]

littleredrooster said:

General Madness said:

Cheers for your advice, Its appreciated.

I noticed though that this morning it did not do it when cold, only once the engine had a bit of heat in it. Does this ring true with what you say?

Yup - typically they break down when hot. Crank sensors can do this also - work when cold, go on strike when hot. (That's not your issue, however, as it would stop the engine altogether).

Great! cheers for your advice.

Could you tell me though, would you bother with diagnostics or just go straight for replacement?

[NateWM]

General Madness said:

It happens when the clutch is engaged. second gear pulling from 1000-2000 rpm there is juddering between 1200-1800.

Cheers

Ah, I see. No chance of it being the clutch then.

Good luck with sorting it.

[browna]

Just a thought to add, could it be rear (or front) brake calipers sticking?
On my mx5 the rear calipers were adjusted too tight and a bit sticky, resulting in an intermitant judder a low speed, fine one rolling at speed. I backed the caliper adjust off, and its better now (recon caliper ordered though)

[littleredrooster]

General Madness said:

Great! cheers for your advice.

Could you tell me though, would you bother with diagnostics or just go straight for replacement?

You need to know which one to replace; if you can suss that out, just replace it.

[General Madness]

It is one coil with four leads running from that.

I have ran the car at idle and pulled each lead one at a time, I struggle to hear any difference but I can see a spark coming from the coil to each lead.

Would this suggest that the coil may be alright?

[philmots]

Id start by throwing a set of plugs at it.. Make sure they're the proper NGK from Renault, iirc they're only available through the dealers. As they're pretty sensitive to them.

If that doesn't sort it then look at coils.

[welaye]

Hello mate,

I've also got a 172 and I had this problem little under a year ago.

It was the coil pack, diagnosed myself by "lending" coil pack from a mate with a clio.

FYI I have been told by Renault techs that the coil pack is an extremely common fault on mk2 Clios.

[General Madness]

philmots said:

Id start by throwing a set of plugs at it.. Make sure they're the proper NGK from Renault, iirc they're only available through the dealers. As they're pretty sensitive to them.

If that doesn't sort it then look at coils.

Halfords sell the Bosch equivalent,

Problem solved.

New spark plugs
Spark plug key
Instant gasket

Less than £30 so I'm happy.