Hello guys. My name is Karim. i’ve owned a megane rs 265 from 2014-2018, sold it after 100k kms. Now i’m back in a 2015 trophy-R with 13,000kms on the odo. Purchased the car from Japan, and had it shipped to Beirut, Lebanon where i live. Car was running perfectly fine, until recently, i’ve been getting some bad jerking/hesitation, what i believe is misfire and power loss. The car starts normally, idles perfectly, and drives perfectly, until I get into boost and hit 5-6k rpm. There’s a slight loss of power from 4-5k, and then complete bugging after 5k. The hotter the car is the more the problem persists. I’ve been searching the net for days now, and from my research, those are the things i gathered: -spark plugs replacement and gapping to 0.6. Done, no result. -fuel filter replacement. Done, no result. -checking of fuel pump pressure. I put a gauge directly at the fuel tank. Constant 5bar pressure. -coils replacement. Done, no result. -camshaft sensor. Done, no result. -o2 sensor downstream and upstream. Not done yet. -thermostat. A lot of people mentioned this. However, the temperature gauge is reading fine. Can it be that the ECU reads temperature from a different sensor? -crankshaft sensor. Not done yet. At this point, I’m really losing hope and don’t know what to do. The car only has 13,000 km on it. I highly doubt that the O2 sensor and crankshaft sensor are bad. Here is a link to the video: https://youtube.com/shorts/l4E7QEQSy7A?si=ZOZiOTLLYDsUJaMg your input is highly appreciated, Cheers karim
What about the type of fuel you are using ???, has it been mapped ??? Revving it like that in the video isn't a good thing, it sounds like it's hitting the limiter so will sound like like its hesitating or miss firing
What Ian says, could just be down to the octane fuel you are using, believe most jap fuel is 102 octane, so if it havn’t had a map tweak to suit whatever fuel you are using it could well be that.
also you can pull out the plugs and inspect the bores with some endoscope, maybe you will find some hint
It does sound like it's hitting the limiter - at a low rpm then redline to protect the engine. And poor fuel is a good chance. However in most cases this symptom is due to a faulty thermostat - as yours is indicating correct running temp (by gauge) then probably not the cause. The 250/265 only has one sensor, so pretty sure same for 275. I would suggest buying/borrowing a good ODB2 scanner (ideally one that can show these in a chart display/format), and look at parameters like temp (confirm actual temp) knock values (normally retards timing; but may switch in limiter?) misfire values (normally useful for idle, but may show faulty wiring/connector to coil packs?) lambda sensor (275 has wideband fitted unlike 250/265) before CAT Otherwise it's going to be difficult and expensive to diagnose.
Hi everyone. thank you for the replies. we spent more than 3 hours on the dyno yesterday trying to figure out what the issue is, with no luck. i’m using the same 98 octane fuel everyone uses, including other megane RSs, and same i use for my 458 speciale and GT3RSs! We also purchased the stock MAP for the car online, and figured its the same MAP that’s on the car after comparing fueling tables etc. Boost is stock @~1.2bar However, i’m thinking i’ll ask our local tuner to tune it down and see if the problem persists.. AFR is normal all the way until it starts misfiring, then the car becomes rich. We also replaced the upstream O2 sensor yesterday with no luck..
We’re thinking it could be a fueling issue. I drove the car 3 times on the japanese fuel it came with, with no issues whatsoever. my first refill was 20L of fuel, then i felt a couple of hesitations, but not to this extent. My second refill a day later was another 20L, and that’s when it went to sh!ts. Again, i’m using the same 98 octane fuel everyone uses, including other local megane RSs (OEM and tuned) and same i use for my other cars! i’m going crazy!!
Okk just called my local tuner. the OEM map he downloadd was also a jap spec map. we’re gonna try loading a euro spec today. i’ll feed u back.
if helps, here you have an stock E6 / 275 my 2016 eurospec map. (there are 2 reads from 2 different tools Kess and MMS Flex) just pass them to your tuner to compare them in winols vs the jap map. https://mega.nz/file/FVZymD7T#EBgpm_pOg8CshBB2E2_Cmi30xsUiv3wp8jJ-7ipkmw4
Hi guys. 1500$ later.. issue solved turned out BOTH O2 sensors were dead. Not 1… the 2 of them, at the same da!n time. Thanks everyone
