Engine problems under heat conditions

desert rat · Post by **desert rat** » 06 Feb 2010, 02:49

Hello,
I'm completely new to this forum so I do apologize if this topic has already been covered. I live in Qatar where i bought a new volvo XC90 2,5T in 2006. Until now we have only driven 60000km, mainly in the city. In summer we have severe starting problems ( it gets here about 50 degree celcius and above ). The car is trying to start but somehow does not make it to really start up. After switching off and on again there is no problem anymore. This can happen daily, and we have been to the workshop extensively. They have changed the complete fuel injection system already but still the problem persists. Does anybody have any idea where we could look next?

Regards,

Rene

Post by **matthew1** » 08 Feb 2010, 15:47

Any messages displayed in the dash? I don't have much knowledge troubleshooting engine starting when it's very hot, but maybe we can stumble on a reason.

Post by **jblackburn** » 08 Feb 2010, 17:04

Possibly a bad engine coolant temp sensor. This affects many of the earlier 5-cyl models...I'd venture to guess the same could happen to an XC. A hot engine does not need a lot of gas to start, and if the ECT thinks the engine is cold, it will dump in tons of gas. It's like starting a warm lawnmower on the choke setting...it just doesn't work.

desert rat · Post by **desert rat** » 16 Feb 2010, 10:58

matthew1 wrote:Any messages displayed in the dash? I don't have much knowledge troubleshooting engine starting when it's very hot, but maybe we can stumble on a reason.

Hi matthew, thank you for your reply. there is no messages in the display, and it only happens in summer when it is very hot. There was another idea that it maybe could be the temperature sensor which has not been changed, whereas the hole injection system including software has already been changed.
Maybe you have another idea that I could have checked?

Rene

desert rat · Post by **desert rat** » 16 Feb 2010, 10:59

jablackburn wrote:Possibly a bad engine coolant temp sensor. This affects many of the earlier 5-cyl models...I'd venture to guess the same could happen to an XC. A hot engine does not need a lot of gas to start, and if the ECT thinks the engine is cold, it will dump in tons of gas. It's like starting a warm lawnmower on the choke setting...it just doesn't work.

Im sure going to try that, sounds like a reseonable option,

thanks,

rene