no crank no start

[Steve Phelps]

Only after driving 30 to 40 mins and shutting the car off it will not start again for about 20 mins.  Starter rolls fine once it has set.  I understand this is common for the 2012's.  Any one have a fix for this?

[Tdci-Peter]

2 hours ago, Steve Phelps said:

shutting the car off it will not start again for about 20 mins.  Starter rolls fine once it has set. 

Is there an audible click from the engine bay fuse box when turning the key to start & it fails to crank? To hear this, open the bonnet & remove the fuse box cover, it will not be a loud click like the solenoid on the stater. If there is a click from the fuse box stater relay, then it is most likely to be a temperature sensitive fault on the solenoid, or the wiring to it.

No click from the relay points to a sensor problem. Clutch switch if manual, or Park position sensor if auto.

Also double check that there are no odd displays or indications from the immobiliser. If it fails to detect the key, maybe due to a dodgy transceiver, there will be a flashing led or message.

[Steve Phelps]

Yes the relay is clicking,  I removed the bottom air damper from under the engine drove for an hour and the car started fine.  I believe with the damper on there is not enough air passing though the engine compartment as it seems to get very hot under the hood.  So I think your right with the heat sensor being tripped on the solenoid.  Thank you for the reply....

[Tdci-Peter]

7 minutes ago, Steve Phelps said:

So I think your right with the heat sensor being tripped on the solenoid.

I was not thinking of a temperature sensor in the solenoid, I have not come across this before, but it is possible. Neither the solenoid nor the starter motor are rated for continuous duty, both would overheat rapidly if kept on for more than a minute or so. The solenoid will overheat very quickly if the starter pinion jams, and the solenoid can not pull in. So there could be a self-resetting current trip in it, but, like I say, it is not something I have heard of.

If there is one, it should not trip at under-bonnet temperatures, even in hot weather. Unless it is faulty.

As a first test, I would monitor the battery voltage when trying to start. The voltage should dip when the solenoid is energised, as that can take 40A or more. And dip more if the stater motor runs. If there is a dodgy temperature sensor, or a dodgy starter relay in the fusebox, or dodgy wiring, then there will be very little change in voltage (If you have a diesel, wait till the glowplugs time out, and the voltage to re-stabilise, before turning to start.)

If the battery voltage falls below about 8v, then the battery is suspect. If there is a modest voltage drop, but no cranking, then the next check point is the earth connection from battery to bellhousing, and the heavy positive wire from battery to starter.

If the starter relay in the fusebox is clicking, that rules out all the complex faults in the PCM, immobiliser & clutch & TCM sensors. So that may be good news. Once that relay energises, the solenoid should pull in, then once the pinion is engaged in the flywheel, the motor should run. Normally this happens quicker than you can hear or see.

Removing the engine bottom cover may be a temporary solution, but it will subject your engine to road spray, with dirt, and in winter, salt. Modern engines, with all the electrics, are probably more sensitive to this than old ones.

 

[isetta]

years ago I had a mk3 escort that would not turn over on the starter when hot. the solenoid on the starter clicked but it would not turn the engine over. Eventually I dismantled the starter motor. I could see from scrape marks that the amerture (the spinning part with coils on) had been scraping on the (static) magnets that surround the amerture. It seemed that the clearance was too small and when hot (due to expansion) the amerture was jamming on the magnets and would not turn. I replaced the starter motor and then all was fine.

My brother had a Chevrolet Camaro (5.7litre V8 with exhausts line drainpipes - what a sound) that had the same problem. He never fixed it but I always reckoned his starter motor had the same problem as my mk3 escort, but he never dismantled the starter motor to check