QuestionRecently the glo plug light on the dash stopped lighting up. now with the cold mornings it is difficult to start the car. do I need to plug the car in inorder to start the car or is it another problem?
AnswerHi Sally,
As you probably know diesels rely on compressing the fuel air unit it reached high enough temperature create spontaneous combustion. The colder the block the more difficult to get this process to happen. The glow plugs is there to preheat the cylinders so the first stroke of compression results in quick start.
When you plug the vehicle in, it has no connection with the glow plugs. The vehicle has a block heater and this heater warms the water and the block, so there better opportunity for the glow plugs to preheat the block.
Once the vehicle has reached operating temperature then the combustion is more easily started.
If you glow plug light has gone out, it just may be a burn out indicator lamp, or it make indicate a problem with the plugs or electrical circuit. Glow plugs can burn out as well.
Also with age, the electrical connections develop corrosion and this decreases the amperage flowing through the circuits.
Make sure your battery or batteries are very healthy. Because diesel engines require higher compression to cause ignition of the fuel, it is harder for the starter to rotate the crank shaft and therefore it must be larger and stronger that a gas vehicle unit. The larger starter requires a larger amperage battery and must be in peak condition.
Cold weather tends to lower the chemical reaction in batteries and lower performance is to be expected.
You may want to find an independent mechanic to have him or her check the glow plugs. and possibly the cylinder compression. If you have leaking valves or poor ring seal, these too can make it difficult to the the proper squeeze on the fuel air for starting.
Good luck
Robert
