Engine wont rev past 5000

[mannors007]

Hi guys,

first post here. I've just bought a Clio RS200 however on the test drive I noticed it wouldn't rev past 5000 revs. I used this as a significant bargaining point and therefore got car for a great price. However now I need to resolve the issue.

On the way home from buying the car I managed to rev the car to the rev line and it felt really strong but it was inconsistent - other times it wouldn't rev past 5000 revs again. I also noticed the car hesitated when accelerating on some occasions.

Has anyone else come across this issue. Not sure its related but the temperature gauge sits in the lowest segment of the gauge, often barely registering any temperature regardless of how it was driven. There is plenty of water in it.

Appreciate your guidance guys,

Andrew

 

[matt9566]

Hi,

Was the car warmed up before driving ? These cars really don't like cold starts and usually take a while to warm up - while cold mine definitely hesitates but that's just one of these cars many 'characteristics' and to be honest I'd never attempt to rev my car up to 5000 until i'd been driving for at least 10 minutes fully ensuring the car was up to temperature.

My temperature gauge has recently started reading really low - I think it will just be that the thermostat needs replacing (in my case) but this hasn't affected the car and it definitely revs easily up to the redline.

Hopefully someone else will be able to shed some more light on your problem, there is plenty of people with a tonne of knowledge on here.

Matt.

 

[mannors007]

Thanks Matt. The car was driven for a good 15 mins before I tried to take past 5000 revs but no joy, it should have been warm enough by then.

 

[Dystant]

Yeah my first thought here is the rev limiter kicks in a lot lower when the engine is cold to prevent damage.

It could be a faulty thermostat, I'd start there as it's a relatively cheap fix.

@Foxspeed is really knowledgable with this sort of stuff maybe he can give some input

 

[sevenfourate]

@Foxspeed is really knowledgable with this sort of stuff maybe he can give some input

Foxy makes Ed China look like Stacey Solomon......

 

[mannors007]

Thanks all. Hopefully Foxy can provide more guidance although I'm going to change the thermostat as it'll be relatively cheap I guess

 

[Christopher]

Even when the engine's stone cold it'll rev past 5k. Ask me how I know. Only once or twice, mind.

Sounds like a CTS issue that's causing it to go into limp, to me. Is the engine management light on as well?

 

[krash67]

Accelerator pedal position sensor? Get a fault code reader plugged in.


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[Antti O]

Time to replace thermosthat and read fault codes with Clip renault diagnostics.
Here you can see where temp should be when warm.
My car takes something like 5 miles for full temp depending outside tempeature.

 

[mannors007]

Thanks for everyone's advice. Christopher what's CTS?
I've ordered a new thermostat as I do think that's the issue with the temp gauge. I'll look at the diagnostics and see if I can get some fault codes.

Hopefully it won't be too expensive.....

 

[mannors007]

Ok guys I got my code reader out and the only stored code is PO325 Knock Sensor Manfunction.

Anyone experienced this?

 

[sevenfourate]

Ok guys I got my code reader out and the only stored code is PO325 Knock Sensor Manfunction.

Anyone experienced this?

Not quite. But i had issues with the knock sensor on my remap.

Basically it just works on harmonics / resonance and doesn't take any actual real measurements or readings from the engine. And if it "hears" something it doesn't like.....(In my case it retarded the timing).

I guess limiting the revs is possible as it goes into "protection mode".......

 

[mannors007]

Hopefully it's a failed sensor. The part is only £30 so will order one tomorrow with a thermostat.

If that doesn't cure it I'll get the car into a specialist

 

[Antti O]

You can also check actual coolant temp reading from obd livedata with obd bluetooth dongle + torque app. When i had bad thermosthat my coolant was approx 60celsius in highway speeds..

 

[Foxspeed]

Even when the engine's stone cold it'll rev past 5k. Ask me how I know. Only once or twice, mind.

Sounds like a CTS issue that's causing it to go into limp, to me. Is the engine management light on as well?

they will the cold rev limit isnt a massive amount...

knock sensor could be the issue if its not working right or malfunctioning it will "protect" the engine ie not allow too much advance

once changed get some good fuel in it oh and dont over tighten it!

 

[krash67]

I agree its the knock sensor being the main culprit. ECU going into protect mode by backing the timing off. Sensor there to detect detonation, fuel flashing off on multiple fronts due to to higher pressure in the chamber and or too higher temperature (lean burn).

 

[mannors007]

Thanks all. I've ordered a new knock sensor, thermostat and service parts so hopefully it'll cure it. The temp gauge barely registering any temp at all has got to be the thermostat.

Just thinking aloud, what would be the issue if the knock sensor was detecting a genuine 'knock'? Is that possible/likely?

Really appreciate everyone's comments and contributions to this thread!

 

[sevenfourate]

^^^Crap petrol / dodgy fill-up with some suspect fuel would get knock-sensor working overdrive.......

 

[Foxspeed]

Thanks all. I've ordered a new knock sensor, thermostat and service parts so hopefully it'll cure it. The temp gauge barely registering any temp at all has got to be the thermostat.

Just thinking aloud, what would be the issue if the knock sensor was detecting a genuine 'knock'? Is that possible/likely?

Really appreciate everyone's comments and contributions to this thread!

the knock sensor detects it all the time as the engine will advance the timing and retard it from the feedback from the knock sensor - most car makers run near or on the knock limit of the fuel as its the way to get the max out of everything - it will detect it before you can feel/hear it and adjust the timing cylinder by cylinder many 1000s times...

as always best to use quality/high octane fuels

 

[sevenfourate]

the knock sensor detects it all the time as the engine will advance the timing and retard it from the feedback from the knock sensor - most car makers run near or on the knock limit of the fuel as its the way to get the max out of everything - it will detect it before you can feel/hear it and adjust the timing cylinder by cylinder many 1000s times...

as always best to use quality/high octane fuels

When i was getting erroneous knock readings from cylinder 2 due to the sensor - my car had a record of 18'000 knocks on that cylinder.......... The others were still in the 1000's !