2.0L BKD - difficult to start hot

[ian]

I find I have starting problems when the engine is cold and has stood for a week, I find that if I turn the key and wait till the Glow plug light goes out and turn the ignition key again and wait for the glow pugs light to go out again it will start no problem
Before ive had to crank the engine for quite a while before it would start .

[mechanic]

I've got a handheld tacho that reflects a laser off a piece of reflective tape that I can attach to the crank pulley.
I'll check this weekend.

If cranking speed is below 280 RPM, why wouldn't it also be hard to start when cold? Do the glow plugs glow during a hot crank?
I wonder if the engine management system is programmed to not glow above a certain coolant temp...

[nutttr]

Same problem with mine... Problem hasn't gotten better or worse in the last 20,000k's, so oh well... On mine it is because it can't crank fast enough when hot.

The engine is a bit tighter presumably when hot and this probably causes a slightly lower cranking speed which means no start till it gets a bit more lubed?! Annoying... Sometimes it takes up to 5s to start, after waiting for glow plugs... I find it much better to start it straight away without waiting for glow plugs when it is hot and it starts better (presumably the battery has a little more power and makes it start a touch easier!)...

(edit - my reasons above are because the ecu doesn't let the engine get fuel until the magical rpm figure.... No idea... But I believe the glow plugs do work on a hot start....)

[Steve879]

Hello, just bought a 2007 TDi jetta and have so far been very happy with the car except for a small hot start issue, the car is just a little hard to start and then only sometimes! You can crank it and it will cough, stall, then crank and it starts, no problem with it once started, heaps of grunt and starts perfect when cold. I have read through this thread and a few others and that it may be a slowly cranking starter motor or a temp sensor? Has a brand new battery and has had a new injector pump in the last 20k. Bit of a shame as the rest of the new car experience has been great. Loving the fuel economy!

[glidn]

I had a 2.0 BKD golf TDI briefly I might add, less than 5 months.

I too had the hard starting issues, thankfully this was a condition of sale repair. the Battery was replaced but problem persisted.
Ended up being a Injector seal causing the problems. Once hot with expansion it was gapping air.

All 4 injectors seals where replaced and re-calibrated. Started first time every time after that.
They replaced the power Cable from the Battery to alternator as well.

I think I would still have owned it till today 4 years later, if it's fuel consumption (only 650km's per tank) was not on par to my MK5 GTI I had owned till last year.
Additionally, replacing the Mechatronics unit 5 times from collection till return. Lost all my hope in owning that car.