In the cold: hard start then runs great. Topic is solved

[JPM]

Hello All,

I've owned my beloved Veronica, '04 V70 with 225k, for about eight months now and she's still in amazing condition. Now that the mornings have been getting colder up here in New England, however, she is having a hard time starting.

Above, 50F she starts flawlessly. The colder it is from there, the longer she needs to crank before it catches and comes to life. Then she immediately runs nice and strong and smooth.

My experience with cars from the eighties makes me want to look at the cold start fuel injector, but I don't think this car has one. If my MAF, coolant or block temperature sensors were bad, I would expect to also have problems at idle and when making power.

Anyone care to suggest where to start my troubleshooting?

TIA,
Jonathan

[oragex]

How is cranking speed? 70F mine was cranking fine, at 40F cranking slow. New battery and it spins at 40F like a squirrel. Perhaps have the battery tested for % of charge it keeps. Mine had great voltage but was charging only at 60%

[Cookie-the-Swede]

Are you using SYNTHETIC 5W30 motor oil? It's your best bet for cold climates.

[Volvo S80]

Hi JPM,

Well the best thing is to test it on temperatures that it usually cranks slowly, if it would happen on my car I would check like this:
1.Check the battery terminal cable`s if they are tight and if there is any rust or something like white build up.
2.Check battery voltage with voltage meter put it on DCV and measure, it should be min 12.4V.
3.Battery load test (you need a special tester which you may find at your local parts store that sells battery`s) and it should show the same CCA as the sticker on your battery.
If 2 or 3 happens to you than you need a new battery if not continue like this.

4.Check the voltage going to your starter, you put the voltage meter lead in negative terminal of battery and the other lead to starter wire solenoid (which you should take it out of starter motor) and ask someone to put the car key to crank position you should see voltage the same as you measured on battery in the 2 step.
5.Sometimes the starter wire jack gets corroded or loose so you might check it as well.
6.If you have low voltage or no voltage than you should check the starter relay.
If 4 happens than you should take the starter out bench test it or replace, if the 6 happens than replace your relay.

I hope I could help.

[abscate]

No cold start injectors on modern engines. The fuel is controlled by the ECU, and when the engine is cold the injector spray more fuel.

If the coolant sensor (ECT) gets faulty , hard starts occur.

Definitely check the battery under load as above

[oragex]

As someone mentioned above, if you have the receipt with the last oil change, check first what grade of oil was used. If the engine has a 10W30 or 10w40 oil, it will get quite viscous below 30's and the battery might have trouble turning the starter quick enough. I would give it an oil change with a 5w30 oil. That being said, the battery may be on it's last leg as well.

[JPM]

Thank you all for the quick replies! I'm not worthy!

Now that I think about it, maybe it is cranking a bit more slowly than usual. Before I pursue battery strength and electrical connection however...

I've got synthetic 10-30 in there, but I realized its pretty old. New synthetic 5-30 is my first course of action. It sounds like that may just do the trick.

The next thing I want to look at is that coolant temperature sensor. Hey abscate, might that ECT you mentioned be called an IAT by Volvo. Is this it, item number 3 in this diagram? http://www.volvopartswebstore.com/showA ... lYear=2004

If so, can someone please point me to a temperature/resistance chart for that sensor? Or is there another way to verify its accuarcy? Is this a data point that might be read with dice/vida?

What a great forum! Thanks again!

[abscate]

This is for my 2005 which I think is the same.

[JPM]

oragex called it first. Replacing the battery did the trick. Cranking time went from more than three seconds to about one. It only cost another twenty bucks to get a modern AGM battery with more cranking amps.

First I changed the oil because it was about time, staying with Mobil 1, but going to 5-30W from 10-30W. That made no noticeable difference, but thanks to cookie-the-sweed for the advice.

I was also able to verify the ECT sensor with abscate's chart. I read about 4kohm at 10degC.

Case closed!

[abscate]

How old was that battery? Five years in New England is darn good.