Trouble starting a car when the engine is warm affects not only older, high-mileage vehicles but also relatively modern designs. What causes it? Does it necessarily indicate a serious fault right away? Below we discuss the possible causes of starting problems in diesel powertrains and petrol engines.
Car struggles to start when the engine is warm
The list of potential faults that contribute to problems starting a car when the engine is warm is quite extensive, which is why it is hard to point to a single source of the problem. It is nonetheless a nuisance, and we would like to resolve these inconveniences as quickly as possible so that our car runs smoothly and efficiently again. To this end, it is best to turn to an experienced mechanic, who will quickly pinpoint the cause. It is still worth knowing the possible reasons and the potential repair costs involved.
Diesel struggles to start when the engine is warm
Many owners of diesel powertrains struggle with the problem of starting an already warmed-up engine. The cause may lie in a lack of fuel in the injector rail, or more precisely in too low pressure in the fuel system.
Leaks in the system should first be sought in the high-pressure pump, or in wear of the common-rail fuel pressure regulating valves. It is there that the rubber seals and diaphragms degrade rapidly under the influence of high pressure. The loss of tightness is also contributed to by contaminants and a high content of undesirable substances that can lead to the hardening and vulcanization of the rubber seals.
Repairing the pump involves an expense of at least 500 złotych. The costs depend, however, on the level of wear and the number of components that need to be replaced. Replacing the entire pump with a new one is unfortunately already a cost in the range of 3-5 thousand złotych - depending on the model and manufacturer.
The cause of problems starting the powertrain may also be the starter, which wears out over time and eventually no longer generates the engine rotational speed required for a smooth start
1.9 TDI struggles to start when the engine is warm
In the case of problems starting a 1.9 TDI engine when warm, we are probably dealing with a worn-out distributor pump or unit injectors. This powertrain has an excellent reputation and is considered very durable, which is why such a situation will most often occur in vehicles with very high mileage.
Fortunately, if we react fairly quickly and do not ignore the problem, it will probably be possible to avoid any more costly replacements. We can opt for regeneration, which will involve a cost of around 1000 zł. There is, however, an alternative - if the wear is not very significant, it is enough to adjust the starting dose on the warmed-up engine, which can be done by a specialist who works with engine maps. Such an adjustment should eliminate the problem with starting the engine, and the procedure will cost us from 200 to 300 zł.
Car struggles to start when the engine is warm - causes in petrol engines
In very many cases, problems starting a warm petrol engine are due to heavy wear of the powertrain and occur in high-mileage vehicles. Above all, the valve seats and the valves themselves may require replacement. This is not, however, the only problem, and the remaining ones fortunately concern less serious matters and are related to the improper operation of:
- the starter,
- the crankshaft position sensor,
- the temperature sensor,
- valve clearance,
- the injection system (in the case of direct injection).
Car starts poorly when the engine is warm - how much will the repairs cost
The cost of repairing the faults that cause starting problems can vary greatly depending on the cause.
As for the starter, very often a simple cleaning is enough, which you can do yourself.
The crankshaft position sensor and the temperature sensor are an expense of under 100 złotych, while valve clearance adjustment carried out in a professional workshop should not cost more than 500 złotych.
The greatest cost awaits you if your car has an engine equipped with direct fuel injection. If it wears out and a replacement becomes necessary, it may mean a repair worth from 1 to 3 thousand złotych. None of these expenses should seem high, considering that ignoring the problem can lead to truly serious damage.
Some faults and the wear of individual components cannot be avoided, because they result from the standard use of the vehicle. However, frequent servicing and the use of suitable protective products as well as high-quality operating fluids help keep the engine in better condition and reduce the risk of unwanted problems arising.
