Cold starting

oleras

Have a 2015 renault megane and last couple of winters its struggling to start in the mornings, could take 6-8 seconds, garage has checked the glow plugs and said they are fine. Starts fine after a journey when warmed up.

Is this just a "thing" that it does ? Could it be the battery ?

Thanks.

Only cold temperature made it harder to start or every morning is the same story?

oleras

https://www.boards.ie/discussion/comment/118610166#Comment_118610166

Just colder temps, summer starting is perfect from sitting overnight.

BlakeS94

Car struggling to start when it's cold could also be a bad battery or poor connection to the battery due to corrosion, you'll know if glow plugs are good because when you turn the key to ignition the little yellow glow plug sign comes up on the dash and goes away within a second or 2, any longer then that means the glow plugs are not working properly.

Starter motor needs more power to start the car in the cold when engine oil would be thicker, so could be that, would also explain why it does start when it's warm.

When it's not starting or struggling, what are the symptoms as you turn the key? Is it 1 single click and then nothing, or is it clicking multiple times and not starting, or is it going "chchchchchchchch" and then fires up?

oleras

https://www.boards.ie/discussion/comment/118610291#Comment_118610291

Push start but its the classic chchchchchchchchchchchch sound. Wants to start but no bang ! mechanoc has checked individual glow plugs and said all ok.

battery so maybe ?

Mech1

If its the original battery it is getting on a bit,, so a new one would be a reasonable first step anyway.

oleras

https://www.youtube.com/watch?v=AfgLvy4zROU

One of the better ones, on a really cold morning it would take 2 or 3 times longer.

Slow, it must be bit faster. Check the battery health, connections etc. Do it before you cook the starter.

BlakeS94

As Mech1 said, a battery wouldn't be a bad bet anyway, cheap to buy and very simple to install, usually just 2 socket sizes need and maybe an extension.

Next time it's cold and you have nowhere to be on time, if/when it doesn't start, try jump starting it, if it doesn't start with a jump-start then the starter motor itself is bad.

Push starting will start a *manual* car under pretty much any conditions.

I think your starter motor is fine though.

That video you posted sounds a bit like a fueling issue to me, the car sounds like it's trying to start, it has a good strong crank it's just taking time to fire up, which tells me there's something wrong with fuel delivery to the engine.

Does it drive smooth under load? When you put the foot down does it jerk, surge or buck? Any of those kinds of symptoms or anything other than a smooth gradual acceleration could be a fuel issue

oleras

https://www.boards.ie/discussion/comment/118610835#Comment_118610835

Drives fine, pulling grand, as i said, once engine is warm or during warmer months it starts as normal, maybe the cold is affecting the battery overnight. I will try the jump start over the weekend and then pick up a new battery.

Its the wifes car so what i might do is swab batteries over the weekend, mine is only 3 years old.

BlakeS94

Okay that's good, I'm just trying to use the process of elimination to help figure out your problem, safe to say we can rule out a fueling problem.

Highly likely the problem lies within the electrical system so, my partners car had the same issue for about 2 years where her car had a bad time starting during winter months and was perfect in the warm weather. On that alone I'd say the battery will fix your issue

oleras

https://www.boards.ie/discussion/comment/118611190#Comment_118611190

As an aside, brother has same year car and has similar experience with cold engine starts, hopefully the battery issue sorts it.

BlakeS94

Keep us updated on what happens anyway

oleras

Update...

I jump started it with my car and it "seemed" to start quicker, roll on next morning and failed to start at all, battery dead after 2 attempts, this never happened before.

Bought a new battery and drove the car myself that day and started each time on the button.

This morning, son was heading off to work and it took 8/9 seconds again to start, to me it seems like a fueling issue, anything i can do to fault find ?

Car is parked level btw.

BlakeS94

Have someone put their ear to the rear seats, and listen for any sounds from the fuel pump while you turn the ignition on, you should hear a low hum if the fuel pump is working, and kind of louder noise or a whining sound indicates its a bad pump.

I would also look into changing the fuel filter if you don't know when it was last done, although I believe those Renault DCi engines can be a pain to bleed air out once the fuel system is exposed to air.

You can put your ear to the handle of a screwdriver and press the end of it against each injector body while cranking, you'll hear a rhythmic clicking if they're good. Bad injectors would throw a light on the dash and you'd have noticed it while driving though.

https://www.boards.ie/discussion/comment/118631238#Comment_118631238

Does not matter the fuel pump noise if pressure regulator let pressure down and pump must restore it every single morning. Also the low pressure side pressure may not enough high. This kind of problems can happens if people drive all the time by fumes. Fuel pump need the fuel for cooling.

OP please make the cold start video on next morning. Last video the cranking speed was too slow. New battery and still slow cranking, there can be completely different problem(s). Ignoring it can request another battery soon.

saabsaab

Does the car drive mainly short journeys not heating up properly on a fast road?

It might be gummed up piston rings. Cure to flush it out with and additive (oil) and drive it hard afterwards to restore compression. This would loosten the rings and help?

oleras

https://www.boards.ie/discussion/comment/118631428#Comment_118631428

https://www.boards.ie/discussion/comment/118631545#Comment_118631545

Will take a vid tomorrow,

saab, its all motorway really, 3ks to mw and then probably 15kms at 120ish,

Too short driving distance, especially for diesel. Every distance is short what takes less than 1 hour driving. 5 days per row ok, but then you need seriously drive on weekends. Only short distances, that engine can not breath soon freely. Load of short distances can build up load of carbon, so it is highly suggested to cut the service intervals shorter. 15 000-25 000 is seriously over kill on that scenario. Most of the "mechanics" does not understand the all engine oil main purposes. The engine oil main purposes is to lubricate, cool and clean the engine. Load of short distances build up the carbon, engine oil and oil filter lose the oil cleaning properties.

oleras

Serviced every year, and the car only does about 10k a year,

Brother has the same car, coming up on 7 years old and has 250+ on his, drives carlow to limerick twice a week, so gets a good spin.

Maybe its just a renault megane thing ?

oleras

Better today, but still not on the button like my own car.

https://www.youtube.com/watch?v=7S_C_Z7lT7c

Slightly faster cranking by new battery. The spectrum analyzing shows difference because the tests is not made on the same condition (door open/close) - nice sound proofing

Because here is already so many suggestions, I suggest too something... Look live data, especially temperature readings. If there fuel pressure sensors, look these too. Desired values and actual values.

saabsaab

Those are short journeys so engine isn't properly warmed up for long.

Perhaps, as said by some old mechanics to me, add a shot of dipethane and 2 stroke oil to your fill up? Have done this myself without adverse effects. Lubricates the system and cleans it.