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Datsuncog's Heaps: Sept 2023 - Another Year's T-Met Exemption Certificate...


Datsuncog

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THREAD INDEX (Kinda) - SEPTEMBER 2023

Okay, so whenever I started this thread I didn't know really where it was likely to end up... but nearly six years down the line, and in the interests of keeping alive some of the more, ahem, memorable stories relating to the ever-hapless DC and his ever-shifting rosta of assorted end-of-life vehicles, I reckoned an index might be the way to go... if nothing else, it might help me find some of these tales of shite-life, amidst the rest of my dross and histrionic ramblings.

So, chronologically, it'd look a bit like this... just click/ poke the embedded link, and thanks to the wonders of modern technology*, it should take you directly to the relevant post.

Nov 2017: Coil Pack Resurrection – 1998 Renault Laguna 1.8 RN Sport, TAZ

Nov 2017: Three Wheels on my Wagon – missing wheelnut fun, TAZ

Nov 2017: Two Lagunas, One Idiot – how not to carry out a simple* repair – TAZ feat. KAZ

Nov 2017: Midwinter MOT Japes in Norn Iron – TAZ

Dec 2017: A Helping* Hand from Next Door’s Cousin – TAZ

Jan 2018: How to fail to fix three different cars in one afternoon – TAZ, KAZ, & The Yaris

Jan 2018: The Furious Hamster Wheel – Laguna Blower Fun, with TAZ

Apr 2018: Kaboom! Morte d’une Laguna – TAZ blows up on the M2

Apr 2018: Rennerwatch – Spring Edition (Total Engine Failure Ahoy!) - TAZ

Apr 2018: It’s… ALIVE!! – 1996 Renault Laguna 1.8 RN bASe Resurrection, KAZ

Apr 2018: No, wait, it’s dead too – KAZ

Apr 2018: L’il Thunder Collection Thread – 2003 Subaru Forester 2.0 XT

Apr 2018: Laguna Departures – KAZ ‘n’ TAZ

May 2018: DC’s Very Shite Trailer

May 2018: Forester Fun (no, really)

Jul 2018: Project Cockroach – MrsDC’s Mk1 Yaris

Aug 2018: Yaris MOT Funsies

Sep 2018: The Forester Report - What's Good, What's Bad?

Sep 2018: Forester MOT Funsies - Achey Brakey Heart

Jan 2019: Running Report: Forester & Yaris UPDATES!

Jun 2019: Unexpected Item In The Baggage Area (Contains 49cc Honda Scooter)

Sep 2019: Flickin' Shit EVERYWHERE: Forester Headlamp Resto

Mar 2021: WEEEEOW WEEEOW WEEEOW – Forester Alarm Disasters

Aug 2021: MOTs In The Time Of COVID - Borderline Yaris PASS

Oct 2021: Ooooh… This Not Good. Forester Near-Disaster (SPOILER: Contains Rust)

Oct 2021: Crispy Fried Forester - Plus Autopsy

Nov 2021: Planes, Trains and Yet Another Bloody Subaru – Caledonian Outback 2.5 SE Collection

Nov 2021: Funeral For A Friend - Forester's Final Farewell

Feb 2022: Outback Issues - Clouds of Doom Gather...

Mar 2022: History Repeating – A Second Helping of Crispy Arsed Subaru

Mar 2022: The Metal Mouse Cometh...

Mar 2022: The Rockin’ ‘Rolla - Bugeye Toyota Corolla E10 Collection

Apr 2022: Scrappin' A Subaru - AGAIN...

Jul 2022: Simple Jobs For Simple People – How To Not Quite Fit A Stereo Unit

Jul 2022: Yaris Pre-MOT Messing

Aug 2022: Yaris: More Mess With A Headlamp Restoration Kit

Nov 2022: Crunchy Corolla (An Unwelcome Theme Continues)

Aug 2023: Spannering Against The Clock - Yet Another Yaris MOT Challenge

Sept 2023: Another Year's T-Met Exemption Certificate...

 

*Unless Renault.

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INAUGURAL POST:

Well, it had to happen sooner or later. I know I've been fairly lucky in the Autoshite department, with most of my shiteworthy heaps only ever developing faults that could be quickly diagnosed and easily fixed. I've skipped over threads on this very forum, detailing maddeningly insoluble mechanical problems, with a slight shudder and muttered supplication to the Gods of Shite. But now it's happened. And - perhaps typically - it's a Renault.

Backstory. I picked up this January 1998 registered Renault Laguna 1.8 RT Sport in Fiji Green - that's the pre-facelift 8v version, 1783cc, fitted with Siemens multipoint injection and distributorless ignition via a pair of coil packs - back in July, at a very moderate price. The seller, an elderly chap who had owned it from new, felt it was "too good to scrap" and I was inclined to agree. Pushing 120k but fairly well looked after and with a new set of belts fitted last year, I figured it was well worth a punt as my loyal but battered and moth-eaten '96 Laguna RN had started to make some odd noises.

IMG_20170930_110225.jpg

She's run well enough for the three months I've used her, only needing a pair of rear wheel bearings so far. So, pushing my luck rather, I thought I'd use her on a break to Galway last weekend. And in fairness she did well, clocking up 800-odd miles on both motorway and fairly rough rural tracks without a murmur - right up until the final stretch back towards Belfast.

Leaving Lusk services north of Dublin, I noticed a bit of hesitation while accelerating back up to motorway speed along the on-slip. Nothing dreadful, just a bit of a hiccup that evened out once we hit 70 and started cruising again. I'd filled up outside Galway (Texaco) and we still had 3/4 of a tank left - and I'd thrown some Redex in at the last-but-one fill-up, just to keep things clean.

About 25 miles on, we had to come to a complete halt for the M1 Toll just outside Drogheda. Pulling away from the cashier booth with the driver window still down, a burbling, jetting roar came echoing back to me from under the car and a LOT of hesitation this time. Fuck, thinks I. The exhaust's bollocksed and I've lost compression. Having hammered along some very rough rural roads for much of the break, this didn't come as a complete shock - my other Laguna had ongoing leaky exhaust issues, while a cracked manifold in one of my Cortinas had produced similar symptoms. No warning lights had appeared on the dashboard or anything, and temperature was still normal.

We hauled off at Castlebellingham services just to make sure the whole system wasn't about to come adrift (nope), and then ploughed on towards the border, reasoning that if we came to a complete grinding halt then the RAC membership would finally come in handy. By now, I had to absolutely floor her in each gear to make progress, with a massive amount of judder and vibration evident, having to take her up to 30mph in second before pulling third, and then couldn't change into fourth gear until she hit 45mph. Once at a steady speed she was okay, but getting there was a struggle and a burbling, chuffing noise (evident even when idling) was audible, loudest at the centre of the car and at the tailpipe - though absolutely no smoke, either white or blue, to suggest a problem with gaskets or piston rings.

We made it home that night, and a quick headscratch the next morning convinced me that maybe the wadding in the centre section of the exhaust had slipped and was part-blocking the pipe, hence the chuffing and possible back-pressure at anything under 2,500 revs. I took her over to a decent exhaust place nearby, where the lad threw her up on the ramps and confirmed that while a pinhole had indeed opened up in the centre silencer causing the rasping noise (which he temporarily cured with a dab of GunGum), the main problem was a misfire coming from the engine.

So. Judder judder judder home again; my next brilliant idea was wondering whether a plug had cracked after a few hours at motorway speed, getting gradually worse as we drove. I knew that neither plugs nor leads were in their first flush of youth; I'd considered renewing them before the trip but decided that it was running well enough and I didn't want to disturb the Lag's underbonnet ecosystem by swapping parts needlessly and throwing everything else off-kilter. Plus, I knew from servicing my other Laguna that it's a pain in the arse getting the right plugs for this engine - the HBOL, Renault and motor factors cannot agree what will fit and what won't, and after several sets of the wrong plugs making my silver Lag run lumpy, I'd just put the old ones back in and left it. (Incidentally, HBOL specifies Bosch WR8D+ plugs with a 0.8mm gap for the 1.8 8v lump - and specifically points out that in this engine, the exact gap is crucial - while a factory sticker on the rocker cover says 0.9mm, while ECP/Halfrauds/local indie claim anything from a 0.7 to a 1.1mm gap in their 'fits your car' online parts searches). But anyway. Up went the bonnet; here's Renault's F3P-670 unit in all its grimy glory:

20171109_183512.jpg

First off, I popped my set of HT lead testers on and fired her up. This showed all four leads sparking away normally at the plug. Which appears to indicate that the coil packs, HT leads and related electrical connectors are, at least, functioning alright. I'd tried to buy some HT leads at Halfords the previous evening, thinking it would do no harm to throw on a new set, only it rapidly became clear that no-one there actually knew what HT leads were, let alone whether they had any in stock to fit a Laguna. So I left it. The metal connectors on all the leads are clean and bright anyway, with no corrosion or gunk.

Next up, I pulled out the existing plugs. These were Champion N7YCX items, in fairly horrible nick. The No.4 plug in particular looked quite badly oiled up. I measured the electrode gap with my feelers and it showed over 1.1mm, so they seem to have burned down a fair bit (the rocker cover sticker on my other 1.8 Laguna - single point injection with distributor - recommends N7YCX plugs, but indicates they should have a 0.9mm gap). Well, this was good in a way - maybe it was indeed a duff plug causing the grief.

20171111_144004.jpg

I rootled around in the shed and found a set of almost-new Bosch WR7DC+ plugs with a 0.8mm gap, allegedly the right ones for my other (single point injection) Laguna - but which had made it run lumpy and got pulled out again after only five miles or so. Reasoning that it would at least prove one way or another whether a plug was at fault, in they went.

On starting, I fancied that the engine sounded a bit smoother - but only a little. I drove it round the block a few times; still some hesitancy, still some judder on acceleration, though not as bad. The HT lead testers were still flashing away, indicating that current was at least getting to all the plugs, though crucially, when I disconnected the lead from the No.4 plug to attach the tester, it made absolutely no difference, nor when I reconnected it again. So it appeared that this was the seat of the problem. Cylinder No.4 isn't firing.

My next thought was - oh right, so if it's not the plug then maybe it's the injector that's failed. I took the No.4 plug out, only to find it already quite blackened - but also soaking wet with petrol. Compared to the other three, this plug was also barely warm - the others were nearly too hot to handle. A strong smell of fuel came out from the bore. Here's the plug in question after a tootle round the block, compared to the No.1 cylinder plug:

20171111_115058.jpg

20171111_115036.jpg

Just in case the Bosch plugs were doing something funny (you laugh, but it wouldn't be the first time a faulty new part has sent me off on a fruitless fault-finding odyssey) I swapped over the NGK BPR6E plugs from my other Laguna (not that new, but gapped at 9mm as spec'd on the rocker cover sticker). Still a spark, but no firing yet at cylinder no.4. None of these plugs I've tried appear to be cross-compatible, incidentally.

And so, dear reader, I'm now rather stuck. Maybe you've been ploughing through this thinking, "well it's obviously the ****, you dolt" - and if so, I'd be grateful if you could let me know. My confusion lies thusly:

  • Current is getting to all four plugs, according to the HT lead testers. I understand this Lag has twin coil packs, using the lost spark system. Is it possible for one of these to break down in such a way that it's sending the current through at the wrong time, or just not enough current to spark? They're about £40 a pop, so I don't fancy buying a new pair just to see if it makes a difference. I do have a cheapo Argos multimeter, however.
  • It seems to me that there's nothing happening at the business end of the spark plug at cylinder No.4 - based on the car running equally lumpy whether or not the HT lead is attached (it's not WORSE when attached, which might hint that it's firing at the wrong time) and the plug's still fairly cold after a few minutes of driving, compared to the other three. Why then has it blackened (seemingly with soot) if there's no ignition happening in the No.4 cylinder? Is something badly wrong with the piston rings here, maybe? Or is the gap crucial here and I'm just using the wrong plugs? The silver Laguna's plugs also showed the No.4 cylinder plug to be significantly sootier than the others, though not actively oily like the one from the green Lag.
  • There appears to be fuel getting into the cylinder alright (as the end of the plug's soaked in it) yet there's no evidence of ignition. If there's fuel, and there's spark, then is the problem overfuelling, or underfuelling, through that particular injector on the multipoint fuel rail? As you can guess, while I'm familiar enough with carbs, I know bugger-all about fuel injection. I'd guess that as the problem first showed itself and then got progressively worse over a period of 100 miles, it's more likely to be a mechanical issue than an ECU issue (?). One snag is that ECP don't even list an injector for this model ("Any part for any car" - that's right, lads), while other online shops say they're about £90 each new - and if you renew one, you should renew them all. A second-hand fuel rail with injectors is about £80 from a breaker - but there seems to be no end of variants and, typically, none of those listed apparently fit my specific model (plus there's 90HP and 94HP versions of the 1783cc unit - and I can't work out how to identify which version mine is).
  • I still haven't seen any of the fabled Laguna 'Christmas tree' warning lights on the dash. I don't have a fault code reader, though I could probably procure one - but is there any point if the car hasn't twigged that there's a fault? Or is it possible that the fault detection sensors themselves are faulty, thereby creating a fault where none otherwise exists? That once occurred on a Toyota Corona of mine, and certainly entertained the mechanics over a period of days...

It's fair to say that although a big fan of shite - Jalopy magazine and James Ruppert's Bangernomics hooked me at an early age - I'm no great shakes mechanically (basic stuff only) and, after a disastrous and expensive foray into post-millennial Alfa Romeo ownership, I self-imposed a rule of 'pre-'96 cars only' - as I've found that I can generally diagnose and fix cars built before this date, but not after. I broke this rule for the green Laguna, reasoning that it was basically the same car as the silver one - but it ain't.

I have a basic toolkit, a HBOL, no garage, and very little common sense. I throw myself upon the mercy of fellow Shiters.

And I'd sooner the answer wasn't "Just fucking scrap it", as I really do like the car very much otherwise and S1 Lags are getting scarce these days. It'd be a pity to weigh it in if there's a simple fix - though my pockets aren't that deep, there are no shite-friendly garages nearby and I do need reliable transport...

Finally - cheers for reading this.

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had similar problems in a (sorry) Zafira, turned out to have a Fubar'd valve...

 

also any water use???

any mayo in the oil??

 

 

May be a a possible HGF..

 

Hope these are of some use in your fault finding

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I would be suspicious of the spark side. If it is getting fuel and I assume air then it isn't igniting fully. Injection tends to different symptoms.

 

Have you checked the colour of the spark? Pull it out with HT lead attached - ground it and see what colour it is.

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had similar problems in a (sorry) Zafira, turned out to have a Fubar'd valve...

 

also any water use???

any mayo in the oil??

 

 

May be a a possible HGF..

 

Hope these are of some use in your fault finding

 

Water levels are still as I left them upon setting off, and there's no mayo showing on the underside of the oil filler cap or any bubbles in the dipstick oil (fearing the worst, I had a quick check at the services, and a better look again yesterday). Hopefully it's not HGF!

 

I hadn't considered the valves, right enough... the air filter's grand, but if one of the valves (either inlet or outlet) is malfunctioning then I can see how spark + fuel are no bloody good without air too (first-form Chemistry, right there) - might take the rocker cover off and hand-crank the engine to see how they're moving.

 

Cheers for the advice! Will let you know how I get on.

 

 

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I would be suspicious of the spark side. If it is getting fuel and I assume air then it isn't igniting fully. Injection tends to different symptoms.

 

Have you checked the colour of the spark? Pull it out with HT lead attached - ground it and see what colour it is.

I'll give that a bash - thanks! I'd started off by thinking it was the plugs, but since last night have convinced myself that it's the injection system somehow - probably because it's an area I know little to nothing about. Will investigate the plugs again and come back to you!

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I'll give that a bash - thanks! I'd started off by thinking it was the plugs, but since last night have convinced myself that it's the injection system somehow - probably because it's an area I know little to nothing about. Will investigate the plugs again and come back to you!

Don't do it too close to the open cylinder tho............

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On 11/12/2017 at 11:42 AM, Mr_Bo11ox said:

Is it not just a dying coil pack?

Well, I'm not sure - seems to be a strong enough spark coming through to all four plugs, although failure of the twin coil packs would certainly be a strong line of enquiry (or at least the right-hand one that feeds the No.4 cylinder). Online diagnostics seem to point to plugs or fuel problems, if the current seems to be getting to the plugs.

Could you recommend any way of checking them - is it possible a dying coil pack sends a weak spark, or fractionally mistimes it? My Dad's old Megane had endless trouble with the coil packs resulting in rough running, though they were individual units rather than the shared jobbers here. Since only one cylinder seems to be affected, I'd have thought that if a pack was dying it might affect both equally? Cylinder 1 seems to be running fine at the moment.

20171111_114844.jpg

I'd be more than happy to sling a new coil pack in if this seems to be the most likely culprit - but just wanted to see what the collective AS mind reckoned before parting with £40-odd quid, in case I'm throwing good money after bad.

Cheers!

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If memory serves there are two identical packs feeding two pots each - it should be possible to switch things around and see if the fault moves with the pack.  I'd still check compression first though.

I see you've already answered the question I've just asked Mr_Bo11ox! Yup, I'll try swapping them round - that should indicate where the fault lies.

 

Apologies for being so dense, that makes perfect sense.

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What they said...

 

A tool worth having around, and will quickly confirm if you do/don't have compression issues.  Otherwise you could well spend hours chasing other faults that  have nothing to do with your current issues.

Sounds easier than whipping the rocker cover off and messing about with valve clearances, agreed!

 

I'll try swapping the coil packs first, and if there's no difference then I'll nip over to Halfrauds and see if I can find someone who (1) knows where the keys to the specialist tools cabinet are, and (2) can follow my outstretched finger to the packet marked 'Laser Compression Tester'. Previous experience indicates that either of these tasks may prove challenging. (Not ragging on Halfords per se - I worked for them a long time ago - but I'm truly appalled at the gormlessness/uselessness of the staff in my local branch)

 

It's probably a handy enough tool to have for £40 (less Trade discount, thanks to the fraudulent card I've held for twelve years now) - I don't mind buying tools so much as unnecessary parts.

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The coil pack is probably a double ended coil - both ends of the winding are used, one for each plug. It is quite possible for the coilpack to break down such that volts go one way much more than the other. Just swap the leads to plug 1 and plug 4. If the fault moves it is the coilpack, if it doesn't, it isn't. **** If it just then runs on two cylinders, the coil pack is seperate coils rather than a double ended one.

 

A quick compression test: ignition off - spin on starter with the plug out of suspect cylinder and put your thumb over the hole. Compare with a cylinder that works.

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The coil pack is probably a double ended coil - both ends of the winding are used, one for each plug. It is quite possible for the coilpack to break down such that volts go one way much more than the other. Just swap the leads to plug 1 and plug 4. If the fault moves it is the coilpack, if it doesn't, it isn't. **** If it just then runs on two cylinders, the coil pack is seperate coils rather than a double ended one.

 

A quick compression test: ignition off - spin on starter with the plug out of suspect cylinder and put your thumb over the hole. Compare with a cylinder that works.

That'd be handier than physically swapping the two coil packs over, right enough. My understanding of coil packs is rather limited, I'm afraid - which is probably what comes from basing my mechanical knowledge on The AA Book Of The Car (published 1984) - so thanks for this idiot's guide! Appreciated.

 

Will also carry out a quick compression test as suggested, though the tool would indeed be handy to have for future use.

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Coil I’d dare say. Later Renaults suffer chronic with it, the pencil type coil per cylinders fail and the STOP light comes on the dash. Aren’t there any Lagunas in the breakers?

 

If you suspect it’s a compression issue see if a garage will do you a compression test, I’d doubt it’s this though.

 

Sounds mad but are you in the AA or whoever? ‘Breakdown’ somewhere and ring them for a free diagnosis. Needless to say, keep mum about it doing it for weeks.

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Okay folks, the quick tests are in - and looks like it is indeed the coil pack at fault, as several of you so sagely advised.

Swapping the HT leads over at the second coil pack resulted in No.4 cylinder coming back on song again, with No.1 cylinder dropping out. So I think that's fairly conclusive. Reversing them back again reverted the problem.

Checking the spark on No.4 by earthing it against the block showed a yellowy sort of spark (more like a sparkler) rather than the blue I'd expect. Strong low sunlight not helping, mind. But it now seems pretty cut and dried as to the culprit.

In my ignorance and haste, I'd assumed that if the HT lead tester bulb was illuminating as expected, then all was well up to the point the current entered the spark plug. This is the first vehicle I've owned without a distributor (other than diesels) so my experience with coil pack problems is somewhat limited.

 

As Halfrauds can't get me a replacement until Thursday, looks like I'll be toddling over to ECP tomorrow to pick one up. Which brings me to my next question - should I replace both of them now, if the other is likely to be on its last legs too? With 120k just clocked up on Saturday, I don't really begrudge it. With their current 35% off weekend promo, they'd be £22.42 each....

laguna coil pack 03-97 on.jpg
 

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Slight 'aside' :)

 

My Savvy has a Clio 16V and the coil leads were all moulded into the coilpack...

Last version of Clio (& Dahhchaa) has a separate coil + 4 leads.

 

I bought a L8 coil + 4 custom made 'high energy' leads and got shot of a intermittent lethargy/misfire.

 

Renault parts are $hite SHOCKER!!!

 

 

TS

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For the sake of £20 I'd probably buy two and just keep the spare, chances are good you'll need it at some point if you're planning on keeping the car.  If they're easy to get at change both and keep the working one as a spare maybe?

 

Beware ECP pattern parts... I've taken to avoiding them like the plague following several poor experiences (dead on arrival parts which they were unwilling to swap without much hassle over "restock fees" and having to get the branch manager involved).  Their part finder system also seems to be about as much use at allocation of the right parts to the right vehicle as a chocolate teapot.  Motorserv and GSF are my usual choice these days given that the independent parts factor is a swine to get to as there's no parking nearby.

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Coil I’d dare say. Later Renaults suffer chronic with it, the pencil type coil per cylinders fail and the STOP light comes on the dash. Aren’t there any Lagunas in the breakers?

 

If you suspect it’s a compression issue see if a garage will do you a compression test, I’d doubt it’s this though.

 

Sounds mad but are you in the AA or whoever? ‘Breakdown’ somewhere and ring them for a free diagnosis. Needless to say, keep mum about it doing it for weeks.

Yup, it seems you're bang on -  though this is one of those odd intermediate 1.8 models that dispensed with the distributor (as fitted to my other Laguna) but hadn't yet got the pencil type coils (on the 16v models from mid-98 on, AFAIK). There's been no dash warnings yet - which is what initially led me to believe it was an exhaust rather than an engine problem, as I understand most Renaults love nothing more than a big warning light jamboree fit to rival Blackpool Illuminations...

 

I might grab a compression testing kit just to have for future use - I've also managed to get a few friends into shite, so sometimes give them a hand with Cortina/Marina issues. One of those things I always meant to add to the workshop but never had a pressing reason to acquire.

 

I can't say I didn't consider phoning the RAC and feigning utter stupidity! Not that much pretence would have been needed... I've got Roadside, Homestart and Relay cover for both myself and my wife (who does need her Yaris for work), so that might have been my next move... ;)

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Yeah but a genuine Renault one would be eleventy trillion quid. The genuine Renault pencil coils used to be sixty quid each from Renault. That’s assuming they stock them, I’d doubt it but you never know. You could always ask, they might let you have it cheap as there’s probably zero chance of them selling it otherwise.

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It is odd that you never got a check engine light, would have expected the lambda sensor to be picking up that something was amiss with the emissions and trigger the light really.

 

Don't be entirely surprised if you have issues with that or the cat itself in future, they don't tend to take kindly to having loads of unburned fuel dumped down the exhaust.  It's a bit luck-of-the-draw whether you'll have issues there or not in my experience, fingers crossed you've got away with it.

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