Hot start issue

[psycho6149]

Hi, my Octavia had the clutch and dmf replaced recently and now I have issues starting when the engine is hot. I have read that the coolant temp sensor is a possible cause. The temp shows fine on the dash, can I test with vcds?

[88rsr]

Is it a 1.9tdi?

[psycho6149]

Sorry yes 1.9 TDI bxe engine

[lee_vrs]

They suffer with starter motor problems when hot

The starter does not turn the engine over fast enough rod I remeber correctly it needs to turn over more than 240 rpm

[trundlenut]

Unplug the coolant temperature sensor when the engine is hot and see if it starts OK.

Sent from my Nexus 4 using Tapatalk

[flying pig]

As daft as it sounds, it could be the battery. I had the same issue and since changing the battery all has been well. Bizarrely, when the engine is warm it requires more cranking power to start it than when cold.

If the battery is becoming tired, it can't supply the required power required hence the difficulty in starting.

Hope this helps.

[trundlenut]

As daft as it sounds, it could be the battery. I had the same issue and since changing the battery all has been well. Bizarrely, when the engine is warm it requires more cranking power to start it than when cold.

If the battery is becoming tired, it can't supply the required power required hence the difficulty in starting.

Hope this helps.

If the PD engines are like the older diesels, when cold fuel is injected immediately regardless of cranking speed. When warm fuel injection doesn't start until the engine is doing 240/250 rpm. So a lazy starter or poor battery causes warm start but not cold start problems.

Sent from my Nexus 4 using Tapatalk

[lee_vrs]

What trundlenut said

[in a leather]

I 'put up' with hot starting problems for a couple of years!  I read about 3 possible solutions but did nothing until I had a big problem starting one day. One of the solutions offered was battery not up to the job. But I could leave the car for a couple of weeks and on returning would fire up first go. Battery? how could it be a battery problem?  More reading showed me why it could be so a new battery went on.  I am now one happy bunny!