Roadster engine cuts out when hot - very distinctive problem

[jusdinoliver]

Hello. I have a very distinctive problem with my 04 Roadster, but can't find anybody complaining of the same thing online.

Basically I drive for about 10mins (until the engine gets warm) and it suddenly cuts-out with no warning. Once stopped it struggles to fire again for a couple of minutes and then starts and I can carry on with my journey. IT NEVER STALLS TWICE . . . just once after about 5-6 miles from cold and then as soon as I have it restarted it is as good as gold.

This is starting to happen everytime I go out.

If I have a good speed and decent throttle (duel carriageway) when it cuts then it will bump itself instantly back into life and then it will not be a problem for the rest of the journey.

I assume that this problem is electrical? and probably one of the sensors? Please has anyone had or heard of this before?

[Fudge]

Re: Roadster engine cuts out when hot - very distinctive problem

Yup (Nodding Head)

[davros7760]

Re: Roadster engine cuts out when hot - very distinctive problem

I would be reaching for a fault code reader - actually I wouldn't, the bloody thing has disappeared in the house move.

The error code will at least give you a starting point for what promises to be
a very interesting fault indeed .

Interesting that with enough forward motion it starts firing again...fuel management possibly......

[Evilution]

Re: Roadster engine cuts out when hot - very distinctive problem

Crankshaft rotation sensor.

[BBE]

Re: Roadster engine cuts out when hot - very distinctive problem

Camshaft rotation sensor.

Is there such a thing on the roadster engine ?
I guess you mean crankshaft rotation sensor (aka Engine RPM-sensor) ?
For the symptom, that makes good sense.
Bjorn

[Mad smart person]

Re: Roadster engine cuts out when hot - very distinctive problem

Greetings, does the engine just stop or just it think about it for a second or two, then stop? Could be the key start switch? You may like to try another gear change/start unit or 'hot'wire the start switch, to see if it changes. May even come right by just pulling the plugs off and putting them back on again? A star computer is the best though for getting some direction but if there's no fault logged, then what happened to cause the engine to stop was not a fault. IE something 'normal' happened to cause it to stop, like turning the ignition off.
Have a look at all the fuses on the SAM, they'er probably all OK except some may be dirty? Cheers.

[Evilution]

Re: Roadster engine cuts out when hot - very distinctive problem

Is there such a thing on the roadster engine ?
I guess you mean crankshaft rotation sensor (aka Engine RPM-sensor) ?
For the symptom, that makes good sense.
Bjorn

Apologies, yeah, Crank not cam.

[jellybean]

Re: Roadster engine cuts out when hot - very distinctive problem

Hello. I have a very distinctive problem with my 04 Roadster, but can't find anybody complaining of the same thing online.

Basically I drive for about 10mins (until the engine gets warm) and it suddenly cuts-out with no warning. Once stopped it struggles to fire again for a couple of minutes and then starts and I can carry on with my journey. IT NEVER STALLS TWICE . . . just once after about 5-6 miles from cold and then as soon as I have it restarted it is as good as gold.

This is starting to happen everytime I go out.

If I have a good speed and decent throttle (duel carriageway) when it cuts then it will bump itself instantly back into life and then it will not be a problem for the rest of the journey.

I assume that this problem is electrical? and probably one of the sensors? Please has anyone had or heard of this before?

I've just had a similar experience while traveling to Merc/Smart Guildford for some parts.

Car all fine, had been driving for approx 15 - 20 mins and engine stalls. Tried to restart the car a number of times but it turned over but wouldn't fire.

Left it for approx 10 minutes & it restarted as if nothing wrong.

Continued my journey, but the car failed again after about 5 minutes. Luckily the Merc/Smart garage was only a few hundred metres away so I pushed it there.

Got them to put it on the Star machine & it pulled up a fault in the crankshaft position sensor.
They said that as the sensor gets hot it's shorting out, and stops the car - it will need to be replaced with a rather big price tag to boot :frown: .

Said I'll think about it & get back to them, drove it away only for the car to stop again 1 mile from the garage. Again 10 minute wait, & car starts - so the car is now back with Guildford for them to mend it!!!!

[krassegrand]

Re: Roadster engine cuts out when hot - very distinctive problem

What is the cost for the crank shaft sensor? Changing it cant be that expensive!

Jörgen

[137699]

Re: Roadster engine cuts out when hot - very distinctive problem

There is a smart independent in Guildford (called Sasho or something like that). I've heard very good reviews about him and no doubt he will be much cheaper than SMerc...

[Evilution]

Re: Roadster engine cuts out when hot - very distinctive problem

You can change it yourself, it's directly below the throttle body.

[madDan]

Re: Roadster engine cuts out when hot - very distinctive problem

http://www.fq101.co.uk/how-to-guides...or-change.html

[jellybean]

Re: Roadster engine cuts out when hot - very distinctive problem

Well got my Roadster back on Friday evening, all running nicely now
It took 3 hours labour by Merc/Smart - they drop the engine slightly to get access. Spoke to the Smart Car Specialist just around the corner from Guildford Smart & they said they do the same and wasn't much cheaper than Merc/Smart. The total bill was £360 inc VAT :frown:, a bit steep but I needed it done quickly. I did have a look at fq101 instructions for changing the sensor, but at the moment I don't have the required tools (T30 torx bit or E10 socket) or the time to do it myself!!!!!!!
Cheers for your help & suggestions.
J.

[madDan]

Re: Roadster engine cuts out when hot - very distinctive problem

Cars never go wrong when you have plenty of time - they just know!

[Evilution]

Re: Roadster engine cuts out when hot - very distinctive problem

Smart either don't think about it, just follow the instructions or don't have a ratchet extension and a UJ.
With the throttle body removed, a bit of swearing and skill you can get the sensor out without the rest of the messing about.