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2.0 DCI M9R engine poor cold start **Sorted at Last**

58K views 73 replies 14 participants last post by  Tmtottibau 
#1 ·
Our Laguna II ph2 has the 2.0dci engine and it is really struggles starting when cold, the engine turns over fine but its as though only one or two cylinders fire up and it takes a few seconds for the others to catch, this producers white/grey smoke. First off I checked the glow plugs and found 2 of them completely failed so replaced all 4. The problem remained. I have tried the primer bulb and whilst there is occasionally air in it the car still struggles to start. I have also tried cycling the ignition to repeatedly heat the glow plugs and this makes a difference some times but not often. I have read for error codes with a generic reader and there was an old stored code associated with the failed plugs but that has not returned and there is nothing else.
Any help?
 
#4 ·
My thoughts then.

Minor leaks in fuel feed system letting in air/fuel run back to tank.
One favourite is the joints on the fuel filter if it is the push in pipe type.
Aftermarket ones are notorious for not quite sealing.
As a check/fix try greasing around the pipe/fitting gap to give a temporary seal.

Could be a small hole/worn bit on any pipe or joint so check all feed system you can.
Remember that the fuel feed is a suction system so unlikely to see more then a trace of diesel/damp patch (if that) at any leak point.
 
#6 ·
Fair enough but principle still applies.

If any joint/seal/gasket is letting air into the system you can get exactly what you describe.

Fuel runs back leaving pump with no prime.
Primer can pull it back up and push towards pump but can take a few cranks for the pump to prime and can still hiccup as lumps of air are sucked into it.

TBH it is about time that engine makers sorted out the diesel fuel system.
It's based on the old timed pump/injection systems and totally archaic with modern common rail and electronic injectors.
A simple low pressure lift pump at/in the tank with a hi pressure pump at engine is all that is needed.
 
#7 ·
That's what Volvo use in fact they have 2 in the xc90 as the prop shaft cause a jump in the fuel tank and the lift pump makes sure the 2 parts are equal. This is a car that was designed in 2000 but it must cost more. Having and working on both, the quality of the Volvo shows up time and time again and is much more of a pleasure to work on.
 
#10 ·
#44 ·
Tho you don't say what mileage is on your dci m9r 1 of the most common faults on these is chain stretch which certainly adds to cold hard starting doesn't affect warm starting. Check it out not a clutching at straws idea
Have you had these points checked?




Cheers.
 
#12 ·
Been looking for evidence of a leak but can't find one. I have also clamped the fuel line over night but that hasn't made any difference also just checked again for fault codes with non found. Running out of ideas unless there is an easy way to check forma leak in the line.
 
#14 ·
Can you check when its cold, how long the heater plug relay is switched on ,i.e. heater plug lead off,multimeter positive lead inside the connector and earth,might not be staying on long enough,then this could point to the engine temperature sensor not reading correct when cold ,
 
#60 ·
Check it out not a clutching at straws idea
Are you sure correct glow plugs fitted, it is a known fault on the M9R engine..
82 00 561 251, are the correct glow plugs...
So changed the glow plugs today. The car hasn't been used for over a week and has just sat there. Went to start it and hey presto it started just as you would expect it to. So I looks like I was right that even though the place I got the replacement plugs from stated that unneeded to have the software updated I didn't and could have just left it as was. Well now I have a set of 11v glowplugs to sell.
So much for clutching at straws.

Glad it's sorted. I've learnt something about M9R's, thanks to this thread.
Ironic that now you've got em, probably too warm to need em, innit?
 
#17 ·
Got the multimeter on this morning when it was about 4 degrees out side. They stayed on for about 1 second. I checked for error codes with the generic reader I have which shows nothing. So many I'm going to give Renault. A call tomorrow to enquire the cost of a replacement sensor.
 
#18 · (Edited)
My Trafic is great in the warm weather at starting, show it some cold weather & it struggles abit - same thing last winter.
Take this morning for instance - (parked it front ways last night against the garage door) volts on the meter said 10.5V, glow plug light stayed on for 3 seconds, started but turnover was slow.
Took it to the little garage i use & they tested the battery with their meter & it said 12.3V but may have a weak cell - poor / replace
It's the original battery i.e. Renault, the vehicle has done 84,789 miles

When it's running the voltage shows 13 - 14 volts

I know it's the amps that really count so i've just purchased a Bosch S5 which is like for like in size but has 5 amps more than 95 & a better cold crank capabilty.

Hopefully that should sort it out for the winter months.
 
#19 ·
The battery is a year old. This morning with the outside temp gauge showing -3 it took 3 goes with the starter button for the engine to final catch. It turns over great but just doesn't catch and when it does final catch it seems to be on one, then two and final all 4 cylinders.
The car has done just shy of 140k but as I said be fore in every other respect it runs great and returns good mph (as long as your not doing lots of cold starts).
 
#20 ·
dont forget to yank out the EGR and check it for gunking up!.
the older Dci's didnt have a PCV valve, post 2005 one's do (to reduce oil being sucked into the intake system)
 
#25 ·
Replaced the engine temperature sensor and it has made a change but it's till not right. It now only takes one push of the button to get it going instead of 2 or 3 but it still takes most of the go and it still feels like it's not catching properly going to try the relay next though I may get a second hand one rather than new.
 
#26 ·
Has the temperature sensor made a change or is it just that the ambient temperature is maybe warmer.


Cheers.
 
#28 ·
I have the same problem with my scenic II 2.0 dci m9r. the car was check in renault garage because the ecu show no mistake. all what a mechanic was found it was a +5 corection on the first injector for about 3 s when its cold. after 3-5s its all ok. they change it with new one but the problem is the same as before. they will now change it back with old one. is it possible that is a egr foult (slightly open)?
 
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