If you’ve got a coolant leak in your Peugeot, that’s a real concern you shouldn’t brush off.
it could turn into overheating and seriously harm your engine. In this article, I’m going to break down why a coolant leak happens and walk you through the steps to tackle it. So, let’s roll up our sleeves and get to it!
Just a heads up regardless of the Peugeot model you’re driving, be it a 206, 207, 208, 308, 3008, 508, RCZ, Boxer, or any other, the reasons behind the leak and the ways to fix it are identical.
The Importance of Coolant to the Engine
Before we dive into the possible culprits behind your Peugeot’s pesky water leak, let’s chat about why water, or coolant, is such a big deal for your engine.
You see, the water and coolant play the crucial role of being your engine’s personal cooling squad. They work tirelessly to cool down your engine and get rid of any excess heat.
Now, picture this. When you’re driving your Peugeot, your engine gets quite hot due to the combustion that is taking place.
This is when your coolant steps in, keeping everything cool. But, if your engine starts running low on coolant or water, trouble starts brewing.
Without enough coolant, your engine ends up working overtime, getting hotter than it should. This can lead to some serious damage and, in the worst-case scenario, even a total engine failure. And we certainly don’t want that!
Peugeot Coolant Leak Common Causes
Now that you know the importance of coolant/water on your Peugeot.
Let’s look at what might be causing it to leak.
From my experience as a mechanic, here are the most common causes of coolant leaks on Peugeot cars:
1. Cracked Water Bottle/Cap:
The leading cause of coolant leaks on Peugeot cars is a cracked water bottle or cap.
If there is a crack in the plastic part of your coolant bottle, it can cause coolant/water to leak from it.
Over time, these plastic coolant reservoirs are known to crack due to wear and tear and other external factors, such as weather conditions in your area.
How to Fix
The first thing you need to check is if the cap is securely fastened to the coolant bottle. If it is, check for cracks in the plastic part of the cap.
If you see some coolant/water drops when adding the coolant, then it might be cracked.
I Recommend replacing the coolant reservoir with a new one. It will come with a new cap as well.
2. Blown Head Gasket
The second most common cause of a coolant or water leak on a Peugeot is a blown head gasket.
The head gasket is responsible for sealing the gases caused by the combustion process in the cylinders and prevents coolant or engine oil from leaking into them.
A blown head gasket is caused by overheating or running the engine on low coolant levels.
When the head gasket blows, you’ll see coolant or water leaking.
How to Fix
Firstly, you need to confirm whether the head gasket is truly the source of the leak.
The simplest method to identify a blown head gasket in your Peugeot car is by checking under the oil cap.
Under normal circumstances, the underside of the cap should appear fairly dry if the gasket is intact. However, if you notice a thick, creamy, yellowish-brown fluid, it could be a sign that your gasket may indeed be leaking.
Other Signs that your Peugeot’s head gasket is blown include:
- Coolant/Water Leak
- Engine Overheating
- Milky Oil Cap and Oil Filter Housing
- Car smoking
- The car vibrates when idling
- White smoke from the exhaust
If you’ve pinpointed a faulty head gasket as the source of the coolant leak, then a replacement is required to rectify the problem.
Luckily, the cost of a new head gasket itself isn’t too steep. However, the labor involved tends to make up the bulk of the repair bill.
Now, if you’re someone who’s pretty handy and comfortable tinkering with your car, you could potentially save a good chunk of change by taking on this task yourself.
3. Bad Coolant Flange:
The coolant flange, also known as the water flange, is like a connector that allows coolant/water to flow into and out of the engine.
It is mainly responsible for keeping your car’s engine from overheating by properly channeling the coolant.
If the Flange cracks or the seal is worn out, then it won’t be able to do its job properly and the coolant will slowly start to leak.
How to Fix
The most common sign of a bad water flange is if your Peugeot losses coolant/water when you drive long distances, but rarely happens if you drive short distances.
In order to fix this, you will need to replace the coolant flange itself since this component is plastic and can’t be repaired.
4. Damaged Thermostat Housing
Let’s talk about another critical player in the cooling system of your car the Thermostat Housing.
The thermostat housing is a plastic component that houses the thermostat on your Peugeot.
The thermostat, in simple terms, is like a traffic cop for your coolant and controls when and where the coolant flows between your engine and the radiator.
Here’s how it works: When your engine is still cool, the thermostat stays closed, keeping the coolant from circulating. But as your engine starts to heat up, the thermostat opens up
This allows the coolant to cruise through the radiator, then loop back into the engine to soak up and kick out the heat.
How to Fix
If the coolant/water leak is caused by a bad thermostat housing. The best way to go about fixing it is to replace the housing.
You should find new housing for roughly $50-100 (£38-76), and labor to replace usually costs $50-90 (£38-68).
5. Radiator Hose Leak
Lastly, the fifth and final cause for a coolant or water leak is a compromised radiator hose(s).
Essentially, the radiator hose is a flexible conduit that serves to connect various parts of your engine, facilitating the flow of coolant throughout it.
However, should this hose develop cracks or undergo a complete breakage, the ensuing issue is rather evident coolant will begin to seep out. This is a situation we aim to avoid to ensure the efficient cooling of your Peugeot’s engine.
How to Fix
When it comes to water hoses, you can either repair/replace them; I recommend the latter.
A quick solution is to use a heat-resistant silicone tap to close off the leak, stopping the coolant from leaking out.
However, this is only a temporary solution and should not be used as a long-term fix.
Can You Drive a Peugeot that is Leaking Coolant?
TBH as a seasoned auto technician, I do not recommend you to drive your car if it is leaking coolant.
You should always try to fix the leak as soon as possible. Otherwise, the coolant can get too low, causing the engine to overheat.
Additional Sources
https://www.gsfcarparts.com/parts/cooling-heating/cooling-system/thermostat-housing.
https://www.howacarworks.com/cooling-systems/checking-for-coolant-leaks
https://www.felpro.com/gaskets-101/signs-of-a-blown-head-gasket.html
Nicely written and very helpful. Thanks!