Hot Start Issue - Mk5 GT TDi 170

[Mp131987]

I knowww before anyone say it 'there are loads of thread covering this'. However, every thread seems to bring up almost something different every time.....

I bought the car in July, and had no problems at all. I did a light service on the car about a month after owning it (oil, filter, air filter, fuel filter). A couple of weeks after doing the service i have noticed the problem and recently it has been getting worse too (particularly embarrassing in petrol stations).

At the week i checked the battery and everything seemed to be ok testing wise. I noticed that it was a 540cca (original also). So i popped down to local factors and picked up a Yuasa battery (740cca), and also grabbed a coolant temp sensor from my local VW garage as i wanted to keep it genuine.

Well, the car turns over at a rate of knots now! but still no luck. Looking into the problems people have had with this and the parts they have changed, i cant see this being a starter motor surely?! as the battery has made a HUGE difference to how quickly the engine is turning over now. But i am absolutely lost where to look next as i am in the same boat as alot of others where buying parts isnt making a difference.

I also had it on a diagnostic machine yesterday and no faults....

Before fitting the new sensor, i had the problem in a Sainsbury car park, and i quickly disconnected the old coolant sensor, and she fired up straight away!

Any advice would be greatly appreciated!

Mike

[Doctle Odd]

I had this problem with an octavia, Crasher of this website sent me a workaround, car now starts instantly. I cant find the thread now bet he posted diagram and details

[Doctle Odd]

diesel warm start problems - Page 2

[Mp131987]

Still got this problem guys, engine is turning over at 300rpm when hot too.

Replaced the fuel filter for another genuine one and still hasn't solved it.

If i can't sort this problem then I will be selling this car asap and getting something better!


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[Mp131987]

Fitted a new Bosch starter motor today and still no luck. Starts a little better but not cured the problem


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[Mp131987]

Anyone?
If I can't get this sorted then it's going to have to be traded in for another BMW


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[niall campbell]

have you changed the fuel temp sender unit ?

[Mp131987]

have you changed the fuel temp sender unit ?

I haven't Niall, is there a way of testing this?

Some people have said it could be camshaft position sensor....and on the 170 that's Cambelt off etc.......


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[Mp131987]

So I had my car go into a local
Garage who have Vagcom, and they noticed that the communication between the camshaft position sensor and crankshaft sensor was apparently reading 65-70% and said that, that was more likely the problem.
Car was due a Cambelt anyway so I said replace Cambelt, water pump, tensioners and camshaft sensor.

On completion of the work the guy called me and said all done, and that my inlet camshaft was out by a tooth!

And now the communication is reading 95-100% on Vagcom between the sensors.

Apparently these are not a usual Cambelt change and that you have to slacken off the camshaft pulleys etc and set them up a specific way, and the previous Cambelt change probably didn't do all this.



But hey, the problem has gone! And I love the car again, and MPG is even a bit better!


So if you have a hot start problem, and the original Cambelt has been replaced in the past, I suggest to either buy the timing tools, or pop it into a garage and get them to check the tension and the timing of the belt!

Happy Christmas guys!


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[niall campbell]

That's great news