Warm engine restart problem.

My 2004 Trident 2500 engine is showing strange behaviour.

It always starts from cold perfectly both Summer and Winter.

But if I try to restart immediately after driving for a few hours it is very unwilling.
The battery really struggles to turn the engine over once, although after a few attempts, eventually it does and it starts.

I'm not sure if it is still the original battery.

If I leave the engine to cool a bit, the longer the better, then it will start without a problem again, although maybe after a few revolutions.

Has anyone with the same engine had this problem or know what the problem could be?

I'd suspect the starter motor.  I have a vague recollection from the dim and distant past of a similar problem.  I think in those days you could fit new brushes, but now it will be a replacement unit.

Hi, thanks, I'll  live with it till next Mot or service and get it checked then, if travel is still allowed

Our 2009 Topaz had a similar problem and yes it was cured by replacing the starter motor!
frederic

Hi Frederic, Thanks for your reply. Seems to confirm where the problem lies. I'll see to it.

We had a problem with our Topaz from new in 2007. The said one of the started motor rings was faulty, so they replaced it, well it still played up once and a while until we sold it in 2015.
I used to dread going on Eurotunnel in case it failed to start, but all was well.

I found really turning the ignition key extra hard a few times seem to work, so maybe the switch.
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Richard

Remember that if done by VW you will get a 2yr warranty on the part & Job.
And yes I think mine also involved the commutator rings.
frederic

Don't forget to check the earth strap on the engine, they can deteriorate with time. Without a proper earth return path a starter motor can struggle.

I had a Commer motorcaravan some years ago eventually having the engine changed. Gradually cold cranking became poorer and poorer. I had the local Lucas agent check the starter motor, it was OK. There was much more I did. Unable to start the van one morning I connected a jump lead from battery negative to the engine and was amazed how fast the starter motor turned the engine over. This was easy to do in the Commer because you sat by the side of the engine.

As Richard says, if it's not the starter motor or the engine earth strap, it's probably the ignition switch, which should not be too expensive to replace (just the switch, not the lock, obviously, as that would cost a small fortune!).

Roopert wrote:As Richard says, if it's not the starter motor or the engine earth strap, it's probably the ignition switch, which should not be too expensive to replace (just the switch, not the lock, obviously, as that would cost a small fortune!).

I would disagree with this. The ignition switch merely energises the starter solenoid and it is the contacts on the solenoid that provide power to the starter motor . You don't have the massive starter motor cables running up to the ignition switch! It might be the solenoid but I think that often that is now a part of the starter motor itself.
If you get sluggish turning of the starter, as opposed to nothing at all, it means that the motor is not getting enough juice - low battery or poor connections somewhere on those massive wires or the earth strap.

inspiredron wrote:

Roopert wrote:As Richard says, if it's not the starter motor or the engine earth strap, it's probably the ignition switch, which should not be too expensive to replace (just the switch, not the lock, obviously, as that would cost a small fortune!).

I would disagree with this. The ignition switch merely energises the starter solenoid and it is the contacts on the solenoid that provide power to the starter motor . You don't have the massive starter motor cables running up to the ignition switch! It might be the solenoid but I think that often that is now a part of the starter motor itself.
If you get sluggish turning of the starter, as opposed to nothing at all, it means that the motor is not getting enough juice - low battery or poor connections somewhere on those massive wires or the earth strap.

Yes I understand that the switch just energises the starter motor, well I should know these things at 72.

Just that the replacement VW starter fitted after 6 months from new did not make any difference. The only thing to work was to really turn the key hard towards the starter position, mine did not even try and start until I did this, then was fine.
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Richard

inspiredron wrote:
I would disagree with this. The ignition switch merely energises the starter solenoid and it is the contacts on the solenoid that provide power to the starter motor . You don't have the massive starter motor cables running up to the ignition switch! It might be the solenoid but I think that often that is now a part of the starter motor itself.
If you get sluggish turning of the starter, as opposed to nothing at all, it means that the motor is not getting enough juice - low battery or poor connections somewhere on those massive wires or the earth strap.

Yes, you're right - with the specific symptoms described (starter turning slowly) it's probably not the ignition switch. I didn't read the original description properly. But the ignition switch is certainly a weak point on many VWs and can be a cause of problems - but probably not in this case!

vanseeker
the only sensible post here is by inspiredron
a test you can do is put your head lights on when trying to start and have someone watch the lights see if the lights go out or just dim a small amount .it sounds to me as a poor connection. lots of people have new starter motors fitted  and was only a poor connection at the starter motor . try a jump lead to earth the battery to engine. test have to be done to find your fault .try some of these test and come back with your results

Hi, Thanks, I'm  happy to try that although it may be some time before I can get in a long run. It's  puzzling because the engine always starts perfectly from cold throughout the year.

it sounds like you have a poor connection and this is getting hot when the engine is running giving you the poor starting

Ok, I'll  check connections tomorrow to see if the fault is obvious.

glyne lock wrote:vanseeker
the only sensible post here is by inspiredron
a test you can do is put your head lights on when trying to start and have someone watch the lights see if the lights go out or just dim a small amount .it sounds to me as a poor connection. lots of people have new starter motors fitted  and was only a poor connection at the starter motor . try a jump lead to earth the battery to engine. test have to be done to find your fault .try some of these test and come back with your results

I am only saying what my fault was. Take it as you like.
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Richard