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Mike Kelly
Mike Kelly, Auto Service Technician
Category: Volvo
Satisfied Customers: 5471
Experience:  17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.
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My Volvo V70 D5 (FV02 GKG) is taking longer to start once

Customer Question

My Volvo V70 D5 (FV02 GKG) is taking longer to start once it is hot.
It starts after a few turns when cool.
This developed suddenly in hot weather and has got worse over the last few weeks.
When it has been on an run after stopping in Motorway service station for example I have to resort to cooling the injectors and fuel lines area down with water before it will start. I am not certain what exactly needs to be cooled to make it start.
I have noticed recently that the fuel economy has dropped but am not certain if the two things started at the same time.
Since the car seems to run perfectly otherwise with no noticeable reduction in power it's a mystery.
Any ideas, Thanks Bob
Submitted: 4 years ago.
Category: Volvo
Expert:  Shantal-Mod replied 4 years ago.


I've been working hard to find a Professional to assist you with your question, but sometimes finding the right Professional can take a little longer than expected.

I wonder whether you're ok with continuing to wait for an answer. If you are, please let me know and I will continue my search. If not, feel free to let me know and I will cancel this question for you.

Thank you,


Customer: replied 4 years ago.

Thanks Shantal, I did not not expect to get an instant solution.


Hopefully there is an experienced Volvo service mechanic who has seen this sort of fault before.


Your Email mentions that you may require more information, if so I will do my best to supply it. Regards Bob

Expert:  Shantal-Mod replied 4 years ago.

Hello Bob,

Thank you for getting back to me so quickly. No further information is needed at the moment. I will continue to look for a Professional to assist you.

Thank you for your patience,


Expert:  Mike Kelly replied 4 years ago.
Hi,my name is mike and I will assist you with your question.
Has the fuel pressure ever been checked and monitored?
Customer: replied 4 years ago.

Dear Mike,

No I have not checked the fuel supply pressure.


I could do that fairly easily if you think that pressure could be the the root of the problem.


The fact that the car runs apparently perfectly when started I had not considered fuel supply pressure.

I had wondered though if the hot diesel was less viscous and therefore less easy to compress.

I assume that the fuel gets hotter around the cylinder head wen the car is first stopped.


I will check the pressure and tell you the result.


Thanks Bob

Expert:  Mike Kelly replied 4 years ago.
Ok let me know thanks,also check the fuel pressure cold and when the vehicle is at operating temperature and let me know,thanks.
Customer: replied 4 years ago.

Dear Mike,

The hot starting fault is developing into an overheating fault I think.

Now after urban driving, although the temperature gauge doesn't indicate overheating the top of the engine is radiating a lot of heat.

Once the engine is stopped and the water is not being pumped round the radiator the temp gauge gets two divisions up from the centre.

The cooling system water looks clean and has not dropped in level ever in the 15 months that I have had it.


The car will then not start until the area around the fuel pipes and injectors is cooled down with water.

Initially the trickle of cooling water evaporates from the fuel pipes and surrounding cover.

It seems to hot to be normal.


I still have not measured the tank fuel delivery pressure but the fault seems more basic.


Please let me know what is likely to be the problem.


Could an overheating problem be created by the engine management system being fed wrong information from a faulty sensor?


Thank Bob.

Expert:  Mike Kelly replied 4 years ago.
The issue that you are having is consistent with a sticking or partially stuck thermostat or the coolant temperature sensor is starting to electrically fail both of which will result in all of the issues that you are having. When replacing either one the coolant sensor or the thermostat it is recommended to replace the other at the same time because one can damage the other.