Non Skoda help please!

[Jane_i10]

My Clio 172 is badly misfiring but as the same time as the misfire developed my exhaust has started blowing, rather badly as it sounds like a Boxer engine.

Could this be the cause? It has blow once before that got repaired with a new crush gasket (it was just past the lambda) but this time it sounds 10 times worse.

I've replaced the coil pack which actually worked till I tried to move the car then it decided to fire on 3 cylinders again

I'm going to try and limp it to a friends work shop, it's completely down on power and engine management light flashing (which it has been doing on and off since I've bought it)

[stu_mcl]

Could be a crack/hole/split before the lambda sensor and the escaping exhaust gas is causing the lambda reading to be wrong so, that would be why the car is running rough and the hole/crack/split would explain the blowing noise

Only an educated guess though

[Jane_i10]

I know its a long stretch for it to actually causing the misfire but its convenient that they both happened at the same time 

[Ade VRS]

Have you checked the coil pack wiring harness?

If it was ok when the coil pack was changed but misfired again when moving the car, maybe the movement of the engine disturbed the wiring again?

The exhaust leak certainly wont be helping though, especially if the leak is close to the Lambda sensor.

If the EML is on it might be a good idea to have it checked for fault codes, might save you a lot of messing.

 

EDIT

 

Just to add, they are prone to leaking rocker cover gaskets so check the spark plug holes for any oil or even water, they like to eat plugs too and sometimes the plug leads will arc out through the head, try unplugging the leads off the spark plugs and wrap some insulating tape around the lead where it goes through the head to the spark plug. Try giving the spark plugs a quick clean with a wire brush too.

Hope you manage to narrow it down a bit, misfires can be a pain to diagnose.

Edited 22 October, 2013 by Ade VRS

[Jane_i10]

Thanks for you reply Ade, yeah i had noticed that the rocker was leaking and this is the next thing to do but with it being a Renault and awkward i have to take off the inlet manifold to access plugs so its not really a 2 second job.

 

Ive read about the corrosion on these wiring harnesses and it seems plausible.

 

I have a list of stuff i want to get ticked off the list but im just a tad dubious about the fact they both happened at the same time  

[Yeti_Man]

My Clio 172... ...sounds like a Boxer engine.

And the problem is? ok so the problem is... You bought French!

I doubt the two things are related. Could you try a new set of leads? Is it doing it 100% of the time? What's the condition of the spark plugs, are they due to be renewed by any chance?

[Jane_i10]

Sorry Mr leaking sunroof..yes that's the best dig I could come up as I adore your car.

Yes it's continuous throughout the rev range but pulling the leads off one by one to hopefully drop it onto 2 cylinders makes no difference, making me think it's not one offending cylinder

[Yeti_Man]

Sorry Mr leaking sunroof..yes that's the best dig I could come up as I adore your car.

Yes it's continuous throughout the rev range but pulling the leads off one by one to hopefully drop it onto 2 cylinders makes no difference, making me think it's not one offending cylinder

Ok, well in that case its buggered so you're best off scrapping it and using that 16mpg city car of yours instead!  Thats the best I could come up with and I thought it was pretty good!

 

Having just done a quick google, theres quite a few reports of misfiring 172 and its usually down to just a couple of things. One that does seem prominent is the cleaning of the ECU connectors... if your plugs, leads & packs are ok then I'd look at this next.

 

http://www.pistonheads.com/GASSING/topic.asp?h=0&t=1302854&d=0&nmt=

 

http://www.renaultforums.co.uk/showthread.php?t=116847

[Jane_i10]

Ok, well in that case its buggered so you're best off scrapping it and using that 16mpg city car of yours instead!  Thats the best I could come up with and I thought it was pretty good!

 

Having just done a quick google, theres quite a few reports of misfiring 172 and its usually down to just a couple of things. One that does seem prominent is the cleaning of the ECU connectors... if your plugs, leads & packs are ok then I'd look at this next.

 

http://www.pistonheads.com/GASSING/topic.asp?h=0&t=1302854&d=0&nmt=

 

http://www.renaultforums.co.uk/showthread.php?t=116847

 

Ha good dig! I do admit

Yeah next port of call is check plugs  and leads but theres a sodding manifold in the way :/

 

Right..utterly confused!

 

Just returned from local garage to have the blowing exhaust examined and the intermediate silencer is one the verge of breaking off, looks like it has been welded before on the other side but now the other side has gone (to the point that mr mechanic was concerned about it coming apart if i continue driving)..so ordered new mid section and will be fitted in due course but the confusing part..it was running on 4 cylinders, only just mind it was very lumpy and skittish with the power delivery but it most certainly fired on all four :/ WTF?

[Soot1e]

The engine management you mentioned is probably the Emissions warning light, the amber coloured one about 4 o'clock on the Speedo,  Mine flickered for 3 years and is not a problem, if it comes on permanantly then the carbon canister or Lambdas are playing up.  

The cracked exhaust you had would sound like it's only running on 3 pots and reduce engine power.

[Jane_i10]

Its the fact two days ago it ran on 3 cylinders and today it runs on 4..it hasnt moved or had any further work done

 

But yes you are correct about the EML light. It has been flashing intermittently for about 4 month now, could go for weeks without coming on then it would do it non stop for one journey. It would go off if i sat stationary for a min or two, then sometimes it would come on then go off 10 seconds later, it was just completely random

[Soot1e]

You can do no more than have the exhaust done and see how the engine runs, hopefully on full chat again. If not you'll  need to have that inlet manifold off and check oil is not pooling in the plug holes for starters, it does come off in a few minutes once you're used to it, just a few 10mm. headed bolts and a 4 loom connectors if I remember right.

  The exhausts for Cups are expensive, I guess you've just found that out.

[Jane_i10]

Would i need to reseal the manifold?

[Ade VRS]

Its a plastic manifold so im sure it will have rubber seals on it, usually good for refitting and resealing themselves ok. Every plastic inlet i have removed so far has had rubber seals if i remember rightly.

[Jane_i10]

Its aluminium 

[Soot1e]

Yes, it's cast ally, not plastic.  The front part of  the manifold has 1 gasket around the inlet ports and there is small gasket around the crankcase vent in the centre of the engine (looks like a chimney). thats  the one that leaks oil into the spark plug wells and out the back of the engine top. The gaskets are cheap enough from a Renault dealer. When  refitting  the manifold, the 10mm. bolts  need to be retightened very gently or they will strip the threads in the head.  

Just remembered- about 8 bolts at the front and 2 next to the coil.

[Ade VRS]

Whoopsie! Could have sworn it was plastic like my F4R one is My apologies Jane.

[Jane_i10]

Ha no worries..btw its back 3 cylinders 

[Jane_i10]

Yes, it's cast ally, not plastic.  The front part of  the manifold has 1 gasket around the inlet ports and there is small gasket around the crankcase vent in the centre of the engine (looks like a chimney). thats  the one that leaks oil into the spark plug wells and out the back of the engine top. The gaskets are cheap enough from a Renault dealer. When  refitting  the manifold, the 10mm. bolts  need to be retightened very gently or they will strip the threads in the head.  

Just remembered- about 8 bolts at the front and 2 next to the coil.

 

Oh i like you, thank you for your info. Been out to have a look tonight and a poke about and there is a fair amount of oil on the rocker so on removal of the inlet it obviously going to worth replacing these.

 

Just been through the history and its has 2 sets of plugs both around 15-20k since 2011 apart so theres a possibly that the seal hasn't been replaced and its leaking..i have hope but regardless going to replace leads and plugs

[Soot1e]

There would be more oil leaking at the back of the engine than the front.   Are you having a go at this yourself? just need a basic socket set. 

[Jane_i10]

Yeah ill doing this myself but unlike most common folk i work weekends so Monday is the day of attack!

Theres a fair amount down the black of the block and some coating the righthand side of the rocker cover. 

 

Its not dripping out as wherever ive parked it theres never been an oil leak

[Soot1e]

Good luck Monday then, let me know how you get on.

[Jane_i10]

Right got the inlet off, all seems in check as for as the oil leak goes, there was no oil in the plug holes. Removed plugs and number 4 and 2 where very black.

 

Ordered new gaskets, ht leads and plugs, all should be here tomorrow, fingers crossed this should work

[KenONeill]

Ok, this is by no means certain, but I've had cars before that ran like a bag of spanners when the exhaust was leaking between the silencers.

 

After that my thinking starts revolving around bad plugs, HT leads and coil pack(s) (delete as applicable), or bad fuel timing but I'd expect that to throw a CEL for emissions, or EMS.

 

Have you checked fault codes yet?

[Jane_i10]

Yeah but now I know the two are not related I can get the misfire sorted first.

The code reader told me multiple misfire, ordered all parts yesterday but for reason they have been put on different deliveries. Coil pack and HT leads already done, just waiting for plugs and gaskets