Ok ive posted this before so apologies , however I will update and hopefully someone can help further , my punto has a lumpy idle , no fluctutation with needle on dash , new plugs , leads , air filter , rocker cover gasket , o ring behind coil seal replaced (no longer leaking oil) new exhaust, however still jumping , no loss of power.

Any ideas please , im desperate, have checked for vacuum leaks and cant find any (im assuming its just the black hoses at the back of engine compartment I should be checking) have cleaned throttle body still no change ,

If I look under car when Rough idling front of exhaust where downpipe meets exhaust shakes , however no leak in new exhaust.
seems to splutter , no loss of fuel and no smoke/problems starting.

A few things that may be of interest , Ive heard on forums that it may be fuel pump but am hoping it isnt, also alternator although apparently working correctly seems to shake when car "jumps"


Other thing is that it has been dripping oil for a while (until I repaired it)
the Oil has dripped onto what I think is the clutch plate just below the coil packs I can see the teeth going around , could this be causing something to slip??


Any help would really be appreciated , I must have spent £200 trying to solve the issue,

Thanks in advance.

car works normally? high oil or petrol consumption?, got power? any lights on dash

Ok forgot to mention , also changed MAP sensor , car drives normally , normal oil /petrol consumption, have power , only light on dash was temp when I changed MAP but now it's gone off , no codes when checked with reader, thanks

Just going off in a totally different direction I'm now wondering if it's the alternator bearings could this rattle the car ? Is there an easy way to check it ?

Neil75 said:

Just going off in a totally different direction I'm now wondering if it's the alternator bearings could this rattle the car ? Is there an easy way to check it ?

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Get a compression check to compare pressures between cylinders. The test can be done wet and dry to give more information.

Neil75 said:

Just going off in a totally different direction I'm now wondering if it's the alternator bearings could this rattle the car ? Is there an easy way to check it ?

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If you suspect something on the auxiliary belt like alternator or a/c compressor is making noise just take the belt off and run the motor. Noise gone, you've found the problem.
What is happening to the coolant level? Early stages of headgasket failure can have slight misfire at idle but generally only when cold and there would be some steam with a coolant smell out the back.
Are all the plugs the same colour. If one is markedly different it could point to a problem with that cylinder.
If oil has found it's way onto the clutch plate I would not expect that to cause a lumpy idle. I would expect jerky pick up when moving off and or loss of drive when accelerating hard.
As judderbar said a compression test would show up valve clearance or headgasket trouble and you get to see the plugs.
Has the car got the original air cleaner and are all it's hoses connected?

Re: punto mk2 , running out of ideas re lumpy idle

Belt isnt noisy Alternator just shakes , easy enough to pull belt off and try without , no A/C. Coolant level doesnt loose a drop , no steam , no smoke , no coolant smell , recently drove 300 miles in it without stopping , didnt miss a beat , only shakes when at a standstill. plugs all the same , not contaminated. new hoses and air filter fitted ,

Thanks for reply.

The alternator is fixed to the motor and should only move the same amount. Any chance one of the three fixings is loose or missing ?

[ame]https://youtu.be/L37j_Khg-i8[/ame]


Hopefully this link will work , if you look at top of airbox and listen you can see vibration and hear rough running , thanks

Neil75 said:

https://youtu.be/L37j_Khg-i8


Hopefully this link will work , if you look at top of airbox and listen you can see vibration and hear rough running , thanks

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The idle seems fine. I have the same problem with my car and I have traced the problem to the catalytic convertor. I have passed two annual emissions tests but there seems some kind of death rattle going on inside that part of the exhaust manifold.

Get a long handled screwdriver as a noise tracer. Carefully put the metal end on various parts of the engine and place the handle to your ear and see where that noise is coming from.

On the left hand side of the engine you can just see a few cms of the edge of the water pump above the oil filter. If the pump is noisy you will hear that sound coming from the pump rather than somewhere else. The screwdriver test is a precise locator of noises.

Neil75 said:

https://youtu.be/L37j_Khg-i8


Hopefully this link will work , if you look at top of airbox and listen you can see vibration and hear rough running , thanks

Click to expand...

all good

flisko said:

all good

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I am assuming he is talking about that horrible dry bearing kind of noise that is coming and going underneath the normal sound of the idle.

neil . you dont say whereabouts you are on your profile. I know a guy (independent) who has had several of these puntos is very familiar with running problems)and if near to you might be worth a visit.

A friend had idle speed trouble on a Mk1 Punto and it turned out to be the ECU unit at fault after spending time and money on other work and replacement parts.

rolandbrindley said:

A friend had idle speed trouble on a Mk1 Punto and it turned out to be the ECU unit at fault after spending time and money on other work and replacement parts.

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Mk1 is same engine - different setup (ecu wise)

Ziggy

Neil, I my be wrong but due to U're problem I'll check tolerance setup between camshaft and valve lifters.
I got 1.4 16v and similar problem with one lifter which make that tapping noise a specially when engine get run, but when straight turned off and restarted tapping noise disappear.
In fact on my doesn't make any rough idling issues but also tapping sound is a lot quieter compare to your's.
Apologies to my writhing [emoji51]