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Robert
Robert, Renault Technician
Category: Renault
Satisfied Customers: 4563
Experience:  Fully qualified 19+yrs exp/self employed technician in the UK
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My Scenic II 1,6 16V doesn't start after pressing the start

Customer Question

Hi Robert,
my Scenic II 1,6 16V doesn't start after pressing the start button. The alternater turns the engine, but it won't start.
It came mol out of the moment.
Where should I start to search. (All fuses are good, fusebox looks proper)
Submitted: 7 days ago.
Category: Renault
Customer: replied 7 days ago.
Scenic II; 2003; real ~115000 km;
Customer: replied 7 days ago.
Scenic II; 2003; real ~115000km
Expert:  Robert replied 7 days ago.

Hi..there

I persume the engine spins over? but doesnt start...

Any warning lights? do you have a scanner?

Was this sudden problem?

Have you checked to see if it has spark and fuel?

Customer: replied 7 days ago.
your persume is right. And no warning lights before it happens.
It was a quite sudden problem. had a problem during the two days before to start the engine. It started "lumpy?"
While I try to start (without success) i smelled fuel, like on my old bike, when it won't start.
I didn't check spark, because the plugs are quite new.
Expert:  Robert replied 7 days ago.

Ok...

I think your best step here is to see if spark is present when you spin the engine over..but first id ensure the timing belt hasnt actually broken..and east way to know that..is to take the oil cap off..and observe the cams inside..have someone spin the engine over and watch the cams spins too..if so then the belt should be fine..sometimes if the engine spins over faster than usual can be another sign of that...but as it stands id certainly check for spark..pull the coils out..and use spark plug tester or even remove one plug and stick into the end of each coil..make sure the sparkplug is grounded..and the see if you can spot it sparking..if not? then id maybe put a guess at a bad crank position sensor..but without scanning and montioring the crank sensor then your pretty much guessing..but nine times out of ten..if you have no spark..then its always due to a bad crank sensor..as they are quite common for failure..the crank sensor sits above the gearbox bellhousing..and held with 2 bolts..so if you can remove that and clean the ensir up.reinstall and then see if that helps...

Customer: replied 7 days ago.
Thank you Robert" for the moment. I'll check your advices on Saturday.
I always thought this crank sensor at that position belongs to the Scenic I series? (no expert !!!)
Customer: replied 7 days ago.
One more question. where are the leads of this crank sensor leading to. Are there connectors in between? (except the on which hooks the sensor to the circuit)
Customer: replied 7 days ago.
Sorry if my English sounds a bit strange. It's not my mother language. :)
Expert:  Robert replied 7 days ago.

thats fine...the sensor lives at the top end of the gearbox beellhousing..thats where the gearbox meets the engine..you'll need to move the air cleaner out the way to see it..at the top the connector goes straight to the sensor..the sensor sits on a curved bracket held with 2 bolts....once you see that then..remove the sensor and check the tip is clean and free of rust..as the tip is magnetic..so can pick up metal filings and prevent it working..sometimes if you plug it in depending if you use a high end scanner you can montior if the crank sensor is working or live data graph it..or you can use scope and back probe the signal wire to see if its feeding back to ecu..but of course you'll need something like a scope to do that...which id imagine you dont have...but like i say above check the sensor visually and check for spark at least and see form there..

Customer: replied 7 days ago.
OK, thank you for the moment. I will check through your list tomorrow.
Expert:  Robert replied 6 days ago.

ok..no problem

Customer: replied 5 days ago.
Hi again,
I checked your list as far as possible with my possibilities.
1. Camshaft is rotating.
2. I checked (just one) sparkplug. There is a spark when the engine is turning.
3. Unmounted the crank position sensor. There was a bit of dirt/rust on the magnetic tip.
I ordered a new sensor anyway. But no after seeing the spark, maybe I was a bit too fast with that.
How should I continue?
Customer: replied 5 days ago.
Hi again,
I checked your list as far as possible with my possibilities.
1. Camshaft is rotating.
2. I checked (just one) spark plug. There is a spark when the engine is turning.
3. Unmounted the crank position sensor. There was a bit of dirt/rust on the magnetic tip.
I ordered a new sensor anyway. But no after seeing the spark, maybe I was a bit too fast with that.
How should I continue?
Customer: replied 5 days ago.
Hi Robert,
i got the information from my wife, who is driving the car most of the time, that there were some random start problems aproxm. during the last 2 weeks. The car just started sometimes weak or started and turned off again. But did it in the 2nd or 3rd round then to run. So this sounds like the described problems with the TDC.
I'm also thinking that it could be a problem with the immobilizer system?
The red light on the dash board is blinking. When I press the start button, it is constantly on for a moment and then it turns off with the engine spinning over, but no starting.
Expert:  Robert replied 4 days ago.

Hi..there..

Ok..well you'll be using the keycard ignition system? maybe try the spare keycard if thats the case to rule that out..sometimes these can be quite common problamatic when it comes to starting..for example the the card reader that you slot the keycard into has small microswitches within it that senses when the cards in,sometims these can get a build up of dust that prevents that,os hoovering out the slot can help..and of course normall practice you depress the clutch pedal fully to the floor and push start..then this will command the immobliser off and the neutral safety switch off.alowing it to start...as far the tdc sensor..goes.theres nothing wrong with trying..what you could do is if you have any easy start..try spraying that into the intake and see if it catches..if not then its means theres no spark..if it does then its fueling problem or immobiliser

Customer: replied 3 days ago.
I tried the second card. No difference. Can try your other suggestions tomorrow.
Thanks so far.
Expert:  Robert replied 3 days ago.

ok.no problem