VW Polo won't start when its hot

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RobDee

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I'm struggling with my VW Polo 2004 model. Every time I drive it a longish distance, the car gets hot. If i turn the engine off it won't start for about an hour (or until the car has cooled down). I've noticed that if I park it in the shade it seems to take less time to recover. I had the car checked by the dealers who said there was nothing wrong. They suspected it was the immobiliser. I subsequently had this bypassed, the problem was not resolved. I read somewhere it may be the temperature sensor. Has anyone else had this problem? Any ideas as to what it could be or how to fix it?
 
I wouldn't think it's the temperature sensor. Mine acts up from time to time (gives me the flashing warning) but temp is spot on and the car runs no problem. I've heard that the coolant temp sensors are generally problematic and need to be replaced if you encounter this fault.

When you say it gets hot, is the temp gauge needle pointing to the middle (ie. optimal operating temp.) or are you edging towards the red?
 
Ok.

Have you replaced the fuel filter yet?

Did you check whether there's a spark (plugs) or fuel coming through (injectors)?
 
The temperature guage indicates that the car is at its optimal temperateure (right in the middle - the needle never moves). But I only seem to have the problem when the car gets physicaly hot, i.e. bakin in the sun or driving long distances
 
And, when you put the key in and turn on the ignition, do you have normal functioning electrics? Any warnings on the dash? And when you turn the key, does it turn over or does nothing happen?
 
I had exactly the same symptoms. Was some sensor on the engine block. It was a round brass thing. Have no idea where it actually is supposed to fit on the engine.

Temperature gauge was normal.
When I took it in apparently the computer showed the error when they ran diags.
 
Have not replaced the fuel filter (or examined anything too carefully under the hood - am not exactly car savy!!) Rely on the dealers and frankly they have been useless so far.
 
Flanders said:
And, when you put the key in and turn on the ignition, do you have normal functioning electrics? Any warnings on the dash? And when you turn the key, does it turn over or does nothing happen?
Click to expand...

All the electrics function perfectly, no warning lights come on. It makes no noise and simply won't start.
 
thisgeek said:
I had exactly the same symptoms. Was some sensor on the engine block. It was a round brass thing. Have no idea where it actually is supposed to fit on the engine.

Temperature gauge was normal.
When I took it in apparently the computer showed the error when they ran diags.
Click to expand...

I'm hoping it's something along this line. It is strange because the fault is not consistent.

When my car was in for its last service though, they didn't mention anything (although I'm not sure they ran a diagnostic - was the 23rd of December and I think they were mentally on leave already).

Was it easy / expensive to replace?
 
RobDee said:
Have not replaced the fuel filter (or examined anything too carefully under the hood - am not exactly car savy!!) Rely on the dealers and frankly they have been useless so far.
Click to expand...

Fuel filter (on my Corolla) gets replaced every 20000kms.

Most people tend not to replace their fuel filters, getting a big surprise later down the line.

If it is the sensor, then you'll need to find out which one it is. Good luck with that one.

Offhand, the only sensors that's on an engine block is :

coolant temperature sensor
oil pressure sensor
knock sensor (to advance/retard timing)

If the knock sensor's faulty, then the engine might not start, or might be extremely hard to start. The first two sensors can fail, but you'll still be able to drive.

I'm not sure what other sensors there might be.
 
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I'm no expert but I'd go with electrical fault, not the temp sensor but something along those lines. Probably what thisgeek said. The temp sensor in my Polo (2005 TDI sl) senses coolant temperature as far as I can tell. It's connected to the coolant container and not the block itself.

Good luck. Let us know what you find.
 
Will return to the dealers and see what they make of my suggestions :D
 
Used to have the same problem espcially when it stand in the sun for too long.Backyard mechanic took out the ignition lock and replaced the plastic covering the ignition, and all was fine.Try that
 
RobDee said:
I'm struggling with my VW Polo 2004 model. Every time I drive it a longish distance, the car gets hot. If i turn the engine off it won't start for about an hour (or until the car has cooled down). I've noticed that if I park it in the shade it seems to take less time to recover. I had the car checked by the dealers who said there was nothing wrong. They suspected it was the immobiliser. I subsequently had this bypassed, the problem was not resolved. I read somewhere it may be the temperature sensor. Has anyone else had this problem? Any ideas as to what it could be or how to fix it?
Click to expand...


Hi, i am experiencing the same problem with my 2003 vw polo. Did you manage to sort the problem out with a new temperature sensor?
 
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