250 Cold start problem

Discussion in 'Mechanical - Engine, Gearbox, Exhaust etc' started by JamesRS250, Feb 27, 2018.

  1. Hi everyone,

    I'm new here, bought my RS250 in December 2017 and have been very happy with it. Just recently it has started having issues on cold starts. It's done 81000kms, always serviced, always run on BP Ultimate 98. Thought it might be the battery so left it on charge overnight but still had the same issue. I go to start it and it will idle rough for a second and stall, then it will do it a second time. Third time it will start but not run smooth until after a couple of minutes.

    Any ideas would be greatly appreciated. The other thing is it only ever gets to the first line on the temp gauge, like at quarter temp, is this normal? All my other cars have sit at halfway on the gauge.

  2. Thermostat is faulty would be my bet
  3. It will be the air inlet temperature sensor, in the boost pipe at the front of the engine, its a red/orangey looking sensor. Had same issue on mine, changed that sensor and it never happened again, make sure its a oem renault one you get. Pattern parts dont fully cure it. Renault ones are same price anyway about £8.
    Mikeyjp likes this.
  4. -Jamie-

    -Jamie- RSM Moderator

    Part no 8200415410R for the sensor, they will say you need an additional wiring loom but you don't.
  5. Could be lots of different reasons from thermostat to excess piston wear. It’s a case trial and error.
  6. Nope, like i said, had exactly the same, and it was the air temperature sensor.
    Mikey4410 and -Jamie- like this.
  7. And also prior to this problem, the sensor first failing, causes kangerooing the first few seconds from cold.
    Mikey4410 likes this.
  8. Thanks a lot for your responses.

    I'll definitely look into getting one of those air temperature sensors.

    I've been keeping an eye on my oil temp, it only ever gets to 76 degrees while driving, this is even in warmer weather. I left it idling in the shed for half an hour and got it to 84, but it makes me think the thermostat is stuck open. I live in Australia so it gets properly hot here.
  9. Was the sensor easy to replace?
  10. Take the engine cover off for easier access, remove the metal clip that holds the plug on and remove the plug, and prise off the sensor using a screw driver, the plastic legs may snap off, make sure you get them out before fitting a new one.
  11. Thanks mate.

    Do you think the one sensor will solve both issues? Start problems and temperature?
  12. Probably not as oil/water temps is seperate all together, so would change your thermastat aswel
  13. Just went out to the car, spotted the sensor, looks straight forward. I want to do the thermostat too but I've really grown a hatred to working on cars, might have to take to the mechanic
  14. Booked in at renault to do the work. Sensor and thermostat were quoted at $140, fitted $340 so I'll let them do it. I'm lazy lol
  15. Thanks very much for your help, got the car back from renault with new thermostat and sensor and all is working great. Cheers
    sph likes this.
  16. Had the same issue this morning, but I haven't driven it for a week, I'll see how it goes.
  17. Your sure it was the red sensor that they changed?
  18. They replaced the part number you gave me. I wanted them to check for fault codes but they said they charge 75 bucks so I didn't bother.
  19. Ebay ones wont solve the kangerooing problem, reanult ones are around the same price (£8ish) and solved the kangoring from cold.
    twistywizard likes this.
  20. Ren it is then cheers :smile:
  21. And like jamie said, they will probably try and sell you a new plug/loom with it for £40, you dont need it, its the same fitting, must be an improved part or something.
  22. Mine hasn't had the issue again since that 1 time that I got it back from renault. Wasn't driven for a week, maybe that's why, fingers crossed.
  23. It's doing it again, every cold start. I've read things online that this is a common problem that doesn't show up on the fault codes and they don't have a fix.
  24. Check the condition of the plug on air inlet temp sensor, theres maybe an issue with them as theres a replacement loom/plug from renault for them, maybe corrosion or something?
  25. I'll have a look cheers. If all looks ok next step will be getting the fault codes checked.
  26. Are any lights on the dash?
  27. No lights. Everything else is perfect, runs excellent once I've let it do its thing in the morning.
  28. Hi im having the exact same problem on my RS250. Did u manage to solve it? Just the same i habe changed the sensor and i had issies with temps so changed the thernostat and the temp are all normal now. Im still having issues starting 1st thing in morning. I had a software update but that didnt help. What is this wiring loom to the air inlet sensor?
  29. Dont really know mate, all i know is when ordering a new air inlet temp sensor, theres a note saying it requires a new loom/plug at £40 odd with it, i just bought the sensor at £8, and when it came it was exactly the same plug fitment as the one ive got, so im assuming theres an issue with plug, maybe not secure enough or corrosion maybe getting in. Mine sorted itself after changing the sensor, also solved the kangerooing from cold aswell.
  30. Sorry are you talking about the sensor no 3 in the pic. Thats the one i changed the one that is right at the top of the housing at the very front near latch for bonnet.?

    Attached Files:

  31. Yes mate, i was saying thats what the new plug is for, but i assum it also depends on the year of the car.
  32. Yeh
    I rang renault and asked about the plug and loom for the sensor they aparently do not have one? Ill ring again but i suspect it may be to do with the plug as after i clean it for a day or two no issues at start up, then it starts happening again.
  33. They probably wont know off there head, as its a note that comes up when putting the air inlet temp sensor part number into the system.
  34. Mine is still doing the same problem, waiting for my next service to get it looked at. Sometimes it helps to hold the start button down a bit longer I find, but doesn't fix the issue.
  35. Im going down to route of cleaning MAP sensor and all other sensors and plugs with electrical cleaner. Cleaning MAP sensor made it rev easier and smoother. My next step is to clean throttle body which i have no idea where it is on a turbo megane. I just cant handle it being as is its bugging me. Ive tried holding the button longer and the results are inconclusive. Lately on the second go when its trying to stay alive ill just step on the gas and rev it up once or twice so its doesn't die again, it feels like it unclogs something or something opens up when i do that. Next thing would be to check the ohm readings on the wiring to the air intake temp sensor.
  36. Front of the engine to the right, its where the pipe with the air temp sensor in goes to it.
    nebz250 likes this.
  37. Charlie Howard

    Charlie Howard RSM Club Member

    Got any results on this? I changed my air sensor and it is better but still not perfect! Might change the thermostat when I change my coolant at the end of the month. Did the cleaning of the plugs sort anything?
  38. The sensor just fixed the kangarooing when cold, still get the cold start issue occasionally.
  39. Charlie Howard

    Charlie Howard RSM Club Member

    My kangarooing is better, but still not 100% solved. Not sure what else to try.

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