W202 cold weather starting problems

[ibrown]

Hi all.

My 1997 W202 (1.8 petrol) starts and runs perfectly until the outside temperature drops below zero.

When the car is left overnight in sub-zero temperatures, it doesn't start (without me heating the engine bay with a hot air gun which is not really a viable long term solution) The engine turns over but doesn't fire and when it does start, it misfires/runs roughly until the engine heats up and then it drive perfectly again.

I have had a local MB specialist run his diagnostic gizmo and no fault codes were found. Battery is good and plugs have been changed.

Any possible solutions or theories would be greatly appreciated as I (we) are stumped.

Thanks in advance

Iain

 

[WOODYTHEWISE]

It sounds very much like a damp problem, condensation caused from the warm engine in the cold air. There was a product called damp start, you sprayed it on the distributor and HT leads. I have no doubt the local motor spares shop will have something suitable.

 

[ibrown]

Thanks for quick reply. Car does not have distributor but two coil packs. Could HT leads be the culprits?

 

[WOODYTHEWISE]

Thanks for quick reply. Car does not have distributor but two coil packs. Could HT leads be the culprits?

Could be HT leads or caps. Make sure they are clean and dry prior to starting.

 

[BlackC55]

I expect a weak spark causing your issue. Use a spark tester to see how powerful it is when cold.

 

[grober]

Check your coolant and air temperature sensors are OK telling the engine ECU to richen the mixture for cold start/running. How old are your spark plugs?

 

[Mr B.]

Try the sparks test like was said an have a look at you ht leads

 

[ibrown]

Thanks for your input - greatly appreciated. Spark plugs and coolant temperature sensor have been changed. Will test for weak spark and checkout HT leads. Fingers crossed.