[classic93]

My fathers 2000 2.2 tid has not started well in the cold for the past 2 yrs, the engine turns over half a dozen times (quite slowly) before firing, the battery doesnt sound healthy although it is almost new, we replaced the glowplug relay a year ago along with the glowplugs but this made no difference, Im going to test the alternator, is there anything else to check as the battery is starting to sound unhealthy again now its cold?
thanks

 

[boris]

- Diesel return pipes? Is the problem worse when the car is parked on a hill with nose upwards?
- Starter motor needing renewal? What's the mileage of the car? What's its behaviour in the summer?
- note that glow plugs become active only at outside temperature below 0 deg. (or something like that). I am developing a hack to always switch them on...

 

[The Seasider]

- note that glow plugs become active only at outside temperature below 0 deg. (or something like that).[/b]

News to me is that !!!!..EVERY Diesel I've ever driven has had the Glow plugs initiated on the turn of the key ...(& that includes everything from a GM Astra to a Kenworth W900)

Now if yer talkin bout the "Cold Start" feature via the Diesel Injector pump (i.e. More fuel) then yeah thats controlled via the Engine Temp Sensor. (which BTW is the main problem with the BMW M51 engine) & why if effected, you can purchase a "Hot Start Fix" (The engine REFUSES to start "When Hot") & by fitting a Relay & resistor if "Fools" the Injector pump into thinkin its actually "Cold" & therefore pushes more Diesel into the Engine.

 

[The Seasider]

Classic ....................

What is the Amperage of the Battery At Crank ??? (Even if you have 12 Volts at rest you may have a Dead Battery Cell) causing low amperage output to the starter motor.

When did you last change the Oil ??& what viscosity oil did you use ....Oil is "Naturally Thick" it goes "Thinner" at higher temperatures, Therefore it will be "Gloopy" & Thick) at low temps Again causing a "Sluggish" turn over of the engine

Battery is next ...Is it a "Sealed" one (i.e. you can't pop off the top to check the Electrolyte levels)

Personally I think yer best route is to whizz it into an Auto Electrician & get the following checked

A. Batt Voltage

B. Battery "Load Test" (As above this will tell you if you have a DEAD CELL within the battery causing a slow "laboured" cranking)

C. Alternator output test (this will tell if the Alternator is actually charging the battery during normal running conditions)


If ALL the above come back as OK (including the Oil Viscosity) then I would suggest you Probably have a Bad Earth on the starter motor.( remember all electrics move in a circle your getting GOOD amperage FROM the Batteery but Little RETURN TO the battery via the Earth points on the Starter motor/vehicle.

An easy way to "get this into your head" is think of pouring water into a container thru a hole....... at the bottom of the container is another hole of the same size therefore (Roughly) the same amount of water exits the container as your pouring in...............Now, block the bottom hole up slightly YES SOME water flows out but NOT ALL & eventually the container overflows ......VERY SIMILAR with Electric current except the "overflow" is turned into Heat & Eventually it will "Cook" the electrical windings (The Wires) within the starter motor & you end up with a "Burnt out Motor" .. The "Hotter" the starter motor get the Slower the engine will turn over ...

 

[boris]

Just for you, my friend:

Glow duration control comprises four functions:
1. preheating
2. starting preparation glow
3. starting glow
4. afterglow.

Ad 1. Depending on the temperature of the engine coolant, preheating starts when the ignition is turned to ON. It depends on the temperature of the coolant; when the preheating is active, the control lamp is lit.
+ 5 deg. C ---> inactive
- 10 deg. C ---> 10 sec.
- 20 deg. C ---> 20 sec.

Ad 2. Starting preparation glow starts after preheating if the preheating time was longer than 0 seconds (duh) and the preheating time has expired.

Ad 3. Starting glow takes place each time the engine is started if the coolant temperature is below 25 deg. C. It is terminated when the engine speed exceeds 750 rpm (or some other time-related criteria).

Ad 4. Once the engine has started, the control module supplies alternate pairs of glow plugs with power. Afterglow starts as the engine speed exceeds 750 rpm and is active for up to 3 minutes, depending on the temperature. From this event on, the quantity of injected fuel is also adjusted to the coolant temperature.

 

[The Seasider]

Cheers fer that Boris .... you put it so much more elequently than I could ......If the OP has already changed the Battery & the Glow plugs I'd still be inclinded to check the Earth straps ect ...bet the Starter motor is Glowin itself after all that slow crankin !!!