XC70: Engine Cold start issues

[Hayvosh]

Hello all,

I have a long going problem with my XC70 2010 (D5244T10 Engine).
For the past two years I've had a cold starting issue that has been haunting me whenever it gets colder outside (below +15C the issues start).

The problem occurs when the car has been sitting for around 8 hours or more, and the problem is that it has a really rough start and what sounds like missfires.
I've had it to Volvo two times, but they cant find the problem and VIDA gives no error codes. When the car is started it starts up rough and missfires some for about 10-15 seconds, then it runs just perfectly.
And when the engine is warm none of this happens, it starts perfect.

Also if I use the diesel heater around 10-15 minutes before I start the car, it also runs just fine, as well if run the electrial parking heater.. this for around maybe 1 hour as it's slower.

What is annoying me also is that I get no fault codes what so ever, so I do not even know where to look.

And the list of replaced things in the car is getting quite huge, I have replaced with both new and used parts.

Compression is also good, around 23kg/cylinder.

So here's the things I've replaced so far:

Battery (new)
Generator (used, charges 14,4 on idle)
Glowplugs (twice, all 5 each time)
Coolant sensor (new)
Fuel temperature sensor (new)
Fuel pressure valves (both high pressure return and low pressure value, used)
Glowplug relay (used)
Exhaust temperature sensor (used)
Lambdasensor (used)
MAF Sensor (new)
MAP Sensor (New)
TMAP Sensor (used)
Starter motor (new)
Fuel filter (new)
Fuel filter housing (used)
Injectors (used, programmed by volvo)
Vakuumpump (used)

This is a video from my car

https://www.youtube.com/watch?v=5_HICgd4waM

[Kev0607]

Try cleaning the throttle body & EGR valve.

Use carb cleaner & have plenty of old cloths available, as it can be a dirty job.

[Bonefishblues]

And PPE. That's carcinogenic gunk.

[Hayvosh]

Originally Posted by Bonefishblues

And PPE. That's carcinogenic gunk.

Just for clarification, what is PPE? :-)

[Hayvosh]

Originally Posted by Kev0607

Try cleaning the throttle body & EGR valve.

Use carb cleaner & have plenty of old cloths available, as it can be a dirty job.

I'll give that a go tomorrow and see if it makes a difference, thanks!

[Bonefishblues]

Originally Posted by Hayvosh

Just for clarification, what is PPE? :-)

Sorry, personal protective equipment. Gloves for sure, and probably a mask too, since you've likely got some lying around!

[Olaf Els]

As the problem is so directly related to the temperature of the engine block, could it be that it's something physical that's reducing compression? Examples are a stuck piston ring or valve stem that then frees up once it has warmed a little. Probably not easy to do a compression test at -15C, but wondering if that would reveal something?

It might be worth trying using a proprietory product that's formulated for the purpose.

On the other hand if your vehicle is 11 years old and the problem is eliminated by using a source of heat, does it matter much if it's not fixed?

[Hayvosh]

Originally Posted by Olaf Els

As the problem is so directly related to the temperature of the engine block, could it be that it's something physical that's reducing compression? Examples are a stuck piston ring or valve stem that then frees up once it has warmed a little. Probably not easy to do a compression test at -15C, but wondering if that would reveal something?

It might be worth trying using a proprietory product that's formulated for the purpose.

On the other hand if your vehicle is 11 years old and the problem is eliminated by using a source of heat, does it matter much if it's not fixed?

Hello and thank you for your reply! :-)

It does not have to be -15 fortunately, but yeah I can ofcourse do another compression test while it's colder outside. Actually a good idea, as the former test I did was indoors.

Can you recommend any good products for cleaning things like this?

You are ofcourse right, it's not really a huge problem. It's more that I want to know the source of the problem as it has been annoying me for such a long time and no one has been able to find the source of the issue.

[Olaf Els]

Originally Posted by Hayvosh

Hello and thank you for your reply! :-)

It does not have to be -15 fortunately, but yeah I can ofcourse do another compression test while it's colder outside. Actually a good idea, as the former test I did was indoors.

Can you recommend any good products for cleaning things like this?

You are ofcourse right, it's not really a huge problem. It's more that I want to know the source of the problem as it has been annoying me for such a long time and no one has been able to find the source of the issue.

I've never had this situation personally, so I am not in a position to recommend any product. If you Google 'piston ring cleaner' or similar, you will be directed towards various products and videos. Some of them may be useful.

I do understand your desire to identify the source of the problem. Things that don't work 100% as intended infuriate me too. Once I know what's wrong, it's more manageable.

Good luck! Please update the thread if you identify the cause.

[Hayvosh]

Originally Posted by Olaf Els

I've never had this situation personally, so I am not in a position to recommend any product. If you Google 'piston ring cleaner' or similar, you will be directed towards various products and videos. Some of them may be useful.

I do understand your desire to identify the source of the problem. Things that don't work 100% as intended infuriate me too. Once I know what's wrong, it's more manageable.

Good luck! Please update the thread if you identify the cause.

This morning while it was cold out, I did a compressiontest before starting the car, and I am no diesel guru by any means but I think these values are ok?

cyl5 - 25 bar
cyl4 - 26 bar
cyl3 - 25 bar
cyl2 - 24 bar
cyl1 - 25 bar