Peugeot repair questions? Ask a mechanic for answers ASAP

Ask an Expert, Get an Answer ASAP!

Peugeot Coolant Troubleshooting

Do you need to know why your Peugeot engine is overheating even with coolant being used? Should the coolant be flushed and how is it done? When problems arise sometimes it can be performed by the owner. However, when additional assistance is needed rest assured an Expert is readily available online to provide you with customized answers.

Read on to know more about typical Peugeot coolant issues and the solutions Experts have to them.

Is coolant the same as antifreeze?

Yes, they are the same but serve two different purposes. Coolant keeps the water from boiling over and antifreeze keeps it from freezing in extremely low temperatures. Normally, when filled into the radiator concentrated coolant/antifreeze is diluted with water in a 50:50 ratio. Coolant also has lubricating properties necessary when in contact with the moving parts, particularly in the water pump. Ethylene glycol is the main chemical element in coolant.

Why does Peugeot 206 coolant begin to hiss and steam after only 10 minutes of driving?

If the fans are coming on, then that problem could be ruled out. Other common possibilities are a faulty thermostat, partial radiator blockage or a failed water pump. Replace the thermostat which is relatively inexpensive. A faulty thermostat could be stuck in the closed position preventing coolant circulation and causing it to heat to a point where it converts into steam. The same thing could happen if the radiator is partially blocked either with debris or because of entrapped air. The solution is to reverse flush the radiator and bleed out any air pockets. If a water pump fails or becomes weak again coolant circulation is impaired resulting in engine overheating and coolant steaming up. These are the most likely cause of excessive coolant heating.

If a Peugeot 207 is driven without a thermostat can coolant damage the ECU?

Without the thermostat, an engine is likely to run too cold or might even overheat in parts. This is because the thermostat is the component which controls both flow and circulation. While uncontrolled coolant circulation is unlikely to cause ECU damage, it is most inadvisable to run a vehicle without a thermostat.

Why is the heating in a Peugeot 407 so ineffective?

It could be because the thermostat has failed. The thermostat holds back the coolant from entering the radiator till the temperature has reached at least 80⁰C. A defective thermostat is likely to be stuck in the open position allowing coolant to  circulate continuously through the radiator. As a result the coolant in this Peugeot 207 never attains proper operating temperature. When this happens the water from the radiator which passes through the heater matrix is never really hot enough to heat it up. Consequently, the air which flows through the matrix to heat the cabin does not get sufficiently heated.

Can a small hole under a Peugeot 206 engine which is causing a coolant leak be stopped?

If an engine is leaking it is difficult to make a repair assessment without a detailed inspection. If the leak is because a drain plug is loose or something similar it can be rectified. However, a hairline crack in the engine block is beyond repair. But there could be other reasons for a coolant leak like a failed head gasket, for example. Try adding ‘Steel Seal’ a coolant additive which might help to seal the leak especially if the leak is very small. If this doesn’t work it would be wise to have a good repair shop take a look and make an assessment.

Why does the engine block of a Peugeot 207 become extremely hot after even a short run?

There are multiple reasons which could cause this. Here are some steps which could be taken which might help solve or trace the problem:

  • Start with the basics – check the oil and coolant level.
  • Check that the fans come on at around 90⁰C.
  • Replace the thermostat which might be faulty.
  • Bleed the cooling system to vent out any air pockets.
  • Reverse flush the radiator to remove any accumulated debris.
  • Check the water pump to make sure it is pumping OK - it could be weak.
  • Check that the coolant or oil have not been contaminated because of a failed head gasket.

Why does a car blow white smoke through the exhaust at random?

Generally, white smoke from the exhaust points to coolant being burned off as a result of head gasket failure. It would help to have a pressure test done on all cylinders and on the coolant system to see if pressure is holding or if there is an internal coolant leak. Check the oil and coolant to see if either is discolored - an indication of head gasket failure. White smoke also suggests unburnt fuel due to various factors including a faulty coolant temperature sensor, faulty mass airflow sensor or defective injectors. These are some of the main factors which cause white smoke out of the tailpipe. There are several others which are more complex.

Because of the multiple systems and elements involved it is often difficult to pinpoint the source of a coolant problem. In such situations, it helps to ask an Expert. An Expert can be counted on for a customized answer in a timely manner.

Please type your question in the field below

3 verified Peugeot Mechanics are online now

Peugeot Mechanics on JustAnswer are verified through an extensive 8-step process including screening of licenses, certifications, education and/or employment. Learn more


Auto Mechanic

Vocational, Technical or Trade Scho

16 positive reviews


33 positive reviews

Trainer/Master tech.

Bachelor's degree

26 positive reviews
See all Peugeot Mechanics