Nonstarter in cold temps .. 2003 C200 CDI

[Plezier]

We currently have temps of around -10 overnight and it's not getting above -2 during the day although they forecast +1 degree for tomorrow. Tuesday morning it was -6 when I tried to start her up now she turns over ok although the instruments LCD screen was pulsing so rather than run the battery down I got the Discovery up to the C200 and attached the jump leads to keep it topped up the problem is although she cranks over OK they was no attempt at firing up almost like no fuel getting though so after few unsuccessful attempts resorted to using engine start spray and it still took several attempts to fire up.

Now we are not getting lack smoke from the exhaust so perhaps it's not injectors maybe weak glow plugs? But of course we know that we have a front SAM module issue as this is the reason the windscreen washers do not work and are currently trying to source a replacement SAM unit but finding one for a C200 T Model with Sequential gearbox it proving to be troublesome. At one point in the afternoon thought I was stranded in the city as although she fired up could not engage any gears at all. Eventually managed to get gears so drove straight home carefully even though had errands to do in the city. This morning even though it was gone 11AM and temp had risen to only -5 again no start so once again used the engine start spray and again it took several attempts so now she is at the garage where George will again scan her and check out her glow plugs, injectors, fuel rail pressure, cam and crank sensors and inspect the SAM module. Have never been happy with how long the engine cranks over before firing up but seeing as this is my first Mercedes experience have no idea as to what is normal or not. Neither the Discovery TD5 or my old Rover 75 CDT needed to crank over much to start so am I expecting too much?

 

[brandwooddixon]

Assuming that you've got winter diesel.
Does the glow plug light come on and then go out? If not then it will be a glow plug issue. Does it produce a lot of heavy, "white" smoke once started that smells of diesel?
It could be air in the fuel line, there have been cases here where the low pressure supply lines crack and air gets in when left overnight allowing the fuel to drain back towards the tank.

 

[Plezier]

Assuming that you've got winter diesel.
Does the glow plug light come on and then go out? If not then it will be a glow plug issue. Does it produce a lot of heavy, "white" smoke once started that smells of diesel?
It could be air in the fuel line, there have been cases here where the low pressure supply lines crack and air gets in when left overnight allowing the fuel to drain back towards the tank.

Well it's supposed to be winter diesel here but George tells me most of it is Russian and of dubious quality and advised me to use a couple of stations in future meanwhile he said go and get some winter diesel additive and put the correct amount into the tank he then told me what he had done and what he had found

Glow plugs are working fine

Glow plug relay is fine

Injectors are fine and have been worked on in the not too distant past

New fuel filter is leaking or the mechanic who changed it spilt a lot of diesel in doing so (need to check this) the leaking diesel was freezing/waxing up!!!

Throttle position sensor on pedal has incorrect voltage, He suggests cleaning the contacts as he suspects a it of corrosion caused by damp as car had been standing on a car lot for some time.

Battery is not that good and really needs replacing

Finally front SAM module is not working properly so needs replacing and he gave me the part number and using it have found a refurbished unit in Germany have sent a message asking about shipping to Bulgaria so now we await a reply.


Have the battery on charge overnight it's already about -8 and it was already down to -6 by the time we got home from picking the car up Friday is supposed to be warmer even getting up to 0 degrees before dropping ack in the minus again. Will price up batteries when in the city Friday afternoon.

 

[tpn]

If the diesel filter is leaking you are fooling yourself expecting it to start easily. Likewise if the battery is not healthy.

You need to take these two issues out of the equation first. Also be careful jump starting.

The biggest problem with the front SAM is moisture. This affects the connectors for the relays.
People and mechanics think that because they get voltage at the SAM, yet the car wont start, that the SAM is faulty.
Simplistic view: These relays are negatively triggered.
I am nearly sure that if you remove the cover of the SAM after a frosty night you will see that the underside of the cover is full of condensation.
I have consistently seen it at zero and -1 so I am sure that -7 will cause the same condensation.
I use loads of electrical contact spray on the SAM,- I practically flood it- sometimes having to use a small screwdriver to help the ECS clean the contacts..

 

[Plezier]

If the diesel filter is leaking you are fooling yourself expecting it to start easily. Likewise if the battery is not healthy.

You need to take these two issues out of the equation first. Also be careful jump starting.

The biggest problem with the front SAM is moisture. This affects the connectors for the relays.
People and mechanics think that because they get voltage at the SAM, yet the car wont start, that the SAM is faulty.
Simplistic view: These relays are negatively triggered.
I am nearly sure that if you remove the cover of the SAM after a frosty night you will see that the underside of the cover is full of condensation.
I have consistently seen it at zero and -1 so I am sure that -7 will cause the same condensation.
I use loads of electrical contact spray on the SAM,- I practically flood it- sometimes having to use a small screwdriver to help the ECS clean the contacts..t

Thank you for your comments now I cleaned off the diesel filter and found that the "so called Mechanic" did not putt he top clip in fully in on the top pipe so I fully pushed it into place and this morning I swapped the battery for a new one that was bought for the TVR. It's a little light at 74ah 640A but it's starting he Merc however the SAM unit is showing up as faulty on the star system it's also why the windscreen washers do not work the pump is good the switch is good but the SAM is not passing any electrical signal from the SAM to the pump. It's also a used unit from a breakers according to George at the garage the SAM has some markings on it so the seller can identify it. Now seeing as the dealer sold the car to me as an automatic chances are that he ought a SAM for an auto and not one fora semi auto sequentronic gearbox. Meanwhile the refurbished SAM unit should be here between 22-24 and hopefully that will sort the issues as right now the car is virtually unusable as if it will select any gears is THE question and IF it does select a gear there is no knowing when it will drop out and refuse to select any gears leaving one stranded.

Lastly we need to find somewhere who knows these gearboxes and can hopefully get the hydraulic oil/fluid changed as there is a small reservoir of the fluid that operates the gearchange as have already had the actual gear oil in the manual box changed.

 

[Plezier]

Thank you for your comments now I cleaned off the diesel filter and found that the "so called Mechanic" did not putt he top clip in fully in on the top pipe so I fully pushed it into place and this morning I swapped the battery for a new one that was bought for the TVR. It's a little light at 74ah 640A but it's starting he Merc however the SAM unit is showing up as faulty on the star system it's also why the windscreen washers do not work the pump is good the switch is good but the SAM is not passing any electrical signal from the SAM to the pump. It's also a used unit from a breakers according to George at the garage the SAM has some markings on it so the seller can identify it. Now seeing as the dealer sold the car to me as an automatic chances are that he ought a SAM for an auto and not one fora semi auto sequentronic gearbox. Meanwhile the refurbished SAM unit should be here between 22-24 and hopefully that will sort the issues as right now the car is virtually unusable as if it will select any gears is THE question and IF it does select a gear there is no knowing when it will drop out and refuse to select any gears leaving one stranded.

Lastly we need to find somewhere who knows these gearboxes and can hopefully get the hydraulic oil/fluid changed as there is a small reservoir of the fluid that operates the gearchange as have already had the actual gear oil in the manual box changed.

Well although she starts up now she refuses to move as now it's a miracle if we get any gears! Moving the lever/selector does nowt most of the time not even getting the message "Select Gear Again" just shows N" all the time and finding information about this gearbox has proven to be difficult it's almost as if it's a state secret! Even searching using the Mercedes number designation of the box only produces Mercedes bumf on how it operates and no real information and nothing about it's bugs and gliches. Did find that the Sprinters have a gearbox that is robotically operated but not if it is the same and the A Class (pretend Mercs) have a robotically operated box that is troublesome in it's operation that does not really help as far as I can tell due to the daft way in which the A Class is set up my only sort of dealing with those in looking at one someone I knew picked up cheap due to it needing a new alternator and it seems that engine removal is needed to change an alternator !!!! Just how stupid is that? Especially when one considers the daft high prices Mercedes dealers charge for workshop time not that I am likely to use them as far as am aware their are only 3 in the Whole country which is surprising when one considers the amount of Mercedes on the roads here. Of course it does not help that none of the dealers are anywhere near where we live then there is the fact that although I have never had a Mercedes before my nephew did have a couple including an S Class and when that developed a problem the Mercedes official dealership was pretty useless diagnosed an expensive part (£2500) as the issue and fitted it only for the problem to return a few days later and he accidently found the real problem when his hand caught the "Sport" mode button which cleared the problem which turned out to be a relay that cost a few quid they also fitted an incorrect rear wheel bearing the collapsed after a few miles but of course that was not their fault.

Am seriously starting to think about getting rid of this Mercedes and I see the Rover 75 that I was interested in before is now listed for sale again seems they got the sensor fitted and at least I know those and their little issues.