Megane 275 Cup-S flashing engine light

Megane 275 Cup-S flashing engine light

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TorqueDirty

Original Poster:

1,534 posts

226 months

Saturday 25th February 2023
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Hi folks,

Just had my low miles (30k) 216 RS 275 Cup-S serviced and on a gentle motorway run yesterday I noticed that the engine block light was flashing.

Got to my destination about 2 mins later, turned the car off, restarted and no lights.

It also seems to be idling a little low, but otherwise seems to be running fine.

A quick google suggests the flashing engine block light means that an emissions issue has been detected.

Any thoughts? I also noticed that the oil level is at absolute max. Could it have been overfilled?

Further googling suggests coils or injectors being possible culprits.

Just seems odd that it was fine until it was serviced and then this warning light appears.

All suggestions appreciated.

ETA: It was this symbol






Edited by TorqueDirty on Saturday 25th February 08:55

KPB1973

929 posts

106 months

Saturday 25th February 2023
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I didn't have this with either of my 275s nor my 250, but an intermittent engine light could be many things, most of which aren't likely to be serious.

It's probably just a sensor detecting something out of spec momentarily. Best option is obviously to get the codes read.

Zarco

18,489 posts

216 months

Saturday 25th February 2023
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Could be a lambda sensor perhaps. Never had it with my 275, but a loose lambda sensor on my 172 Cup through up that light once.

Not a Diesel

71 posts

222 months

Wednesday 22nd March 2023
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I had a Lambda sensor go on my 2016 Cup-S. No difference to driving but had the light. It stayed on.

Also recently had minor miisfire after servicing with a rough idle too. It turned into a bad misfire.

They checked the plugs and one had a crack in it after 3k, 6m. I got them to change the coils & pugs. Sweet after that.

My thinking is plug may have been damaged (dropped) in transit or install & just got worse.

tobytronicstereophonic

54 posts

69 months

Friday 7th April 2023
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If the oil level was too high, that could have been the cause. The motorway run burnt off the excess oil and the oxygen sensors/cat are now happy.
The faulty/cracked spark plug insulator suggestion is plausible. I did it myself as an apprentice helping a mechanic service an RS2000 mk2 Escort. I dropped the new plug, and didn't spot the hairline crack. The car came back, but the mech had since left to work for himself. To my shame, I didn't admit to being the culprit. Sorry Les.

Get the ECU scanned to see what's been stored?
I will gladly scan it for you if you are in the East Lancs area FOC. I have a decent scanner with software for all Euro models.

Edited by tobytronicstereophonic on Friday 7th April 12:12

TorqueDirty

Original Poster:

1,534 posts

226 months

Wednesday 26th April 2023
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Hi folks,

Vary late coming back to this - so thanks again for the input

Still have the same issue so will take it to the local garage and get them to take a bit of the oil out, as I'm convinced it is still way too full.

I'll also replace the plugs and one of the coils to see if that makes a difference. I'd prefer to replace all 4 coil packs but the RS ones are seriously pricey so I'll go with one to start with I think.

ODB Code reader is saying misfire on cylinder 1 as well as Camshaft position sensor bank A (from memory). Dumb question but which one is cylinder No 1? Left or right of the engine as I am looking down on the engine with the bonnet up?

Also, and recommendations on what plugs and coils to go for would be appreciated.




TorqueDirty

Original Poster:

1,534 posts

226 months

Thursday 14th December 2023
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So the saga continues.

Recap. Got car serviced earlier this year. It came back running like st and then engine light came on.

The exhaust stank too - of oil.

Checked oil level. Was way too full.

Spoke to servicing garage but they refused to do anything about it - apart from clear the fault codes.

Took car to friendly local garage who took about 1.5 l of oil out and it was still reading just on max oil level.

Then replaced the plugs and coils on the basis that they were likely to be shagged from oil contamination. The plugs were horrendous. One was actually covered in oil and was even lose. The oil was all the way up the pencil coil too.

I conclude that the person who serviced the car previously was a moron / massively hung over / both. I'm genuinely beginning to think that they did not actually drain the old oil before adding the new stuff.

Anyway, after replacing the plugs and coils the car runs way better but still running rich and a bit lumpy on idle.

Then got the oil completely drained and replaced by someone who actually knows how to service a car to make sure that the oil level is now right. However they did not have the right diagnostic tools to determine the cause of the rough running.

Finally caved and took it in to Renault this week. They charged me £150 to plug it in to the diagnostic machine and predictably not come to any conclusion. They did however kindly offer to run 3 more hours of diagnostics for the bargain price of £550.

After cross examining them they did eventually tell me that that the upstream oxygen sensor was running out of spec - resistance too high. Hmm, well that makes sense right? If it is covered in partially combusted engine oil and probably explain why the car is not running very well.

So, rather than play main dealer diagnostic bingo at £550 per go I think I'll just replace the O2 sensor (about £150) and see if that sorts things out.

Is it reasonable to assume that a huge excess of oil would result on engine warning lights, stinky exhaust, shagged plugs / coils, rough running and a knackered O2 sensor?

I'm tempted to invoke Occam's razor on this and go with the most likely explanation rather than dive in to eye wateringly expensive diagnostics to probably come to the same conclusion.

Thoughts / suggestions welcome.











RS_MAN_CHILD

291 posts

276 months

Friday 15th December 2023
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Dealers cannot be trusted to service these cars time & time again they do not pay attention! Most could not care less either their attitude is terrible. Over fill on the oil is serious it can cause major engine damage as the oil gets into places its not supposed to reach!

Mine came back with minor scratches & unexplained extra miles......never again I DIY it all myself now less stress less hassle just buy the tools DIY!

Zarco

18,489 posts

216 months

Friday 15th December 2023
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My trusted indy (well, previously at least!) royally cocked up a cambelt change on mine. Wish I'd taken it to Renault for that, despite me not being particularly impressed by their service in the past.

It does pay to find someone who knows their way around these cars.