Problems with the Peugeot 308 T9 coolant

I recently noticed that the coolant in the expansion tank behaves strangely. There is an unpleasant feature and problem. The details are in the video.

[@k1ll3runa]

I had the exact same issue on the DV6TED 1.6. It was a blown head gasket. I tried all the steps before that. Air bleeding, new expansion cap, chemical head gasket test. Everything came up fine. I then noticed my original cap valve was shut close and would simply never open and when I remove it the coolant would expand almost to the top, and the blown head gasket kept blowing into my cooling system until it reaches so much pressure that the antfriize would go into cyl. 1 & 2 overnight. Changed the cap and it started spewing coolant due to compression leak in the cooling system, Head bolts were not renewed when we did a head gasket job 2 years prior. It's a small amount that's being burned and you won't notice it smoking from the tail pipe. We opened it up and found coolant in between the head and and the gasket. Fire rings were blown as well. Water pump was fine , thermostat was fine, system was bled, cap was replaced with Peugeot OEM. So I just decided to bite the bullet and open up the engine, to noone's surprise it was burning coolant by small ammounts. The compression leak only happened at highway speeds upwards of 120 km/h+ especially on climbs, only then would the combustion pressure be strong enough to bleed through the gasket.

[@peugeoton4033]

Thank you so much for the information. I'll be watching.

[@christosfiniris3495]

I have the same issue. 2.0 BlueHDI engine. I installed NEW AGR 6 months ago, new Cap, etc but i still have the same issue. every 500km i add about 0.5L antifreeze. I believe is a small leak from the radiator, and is impossible to see it., I will ask my mechanic to add some coolant sealant, and i hope it will stop.

[@miguelcalzadilla5757]

Go thru the bleeding process, there are valves in the motor for it, i think you have air in the system and because of the cold temperatures that does not affect you, but in summer will be an issue

[@MrKumplung]

I have the same car same engine, had the same "issue" with the coolant level not so drastic level changes as yours but I've noticed it, the first time I've noticed I thought it's normal throughout the year car to lose a bit of coolant and filled up to max, after that again I've noticed the level dropped aroun 1/2cm and wanted to test what happened didn't filled up the tank instead drove it for about 20min and when I arrived home the level was fine at max, since then I periodically check the level and it didn't happened again this was around 3 months ago.

[@Mohamad-zk8bk]

Hello, you have to buy several caps before finding the right one. Also try to remove air from the thermostat when the engine is hot via the bleeder screw.

[@franmihael]

I have the same problem. All gaskets are changed, waterpump done 10k kilometers ago or something like that. Even changed the cap once. Still nothing. I have some trouble with the heater tho, so I'm probably changing that as well soon, but I don't expect it will fix the water level oscilations.

[@AlexM-tz8uo]

I have the same problem on my Peugeot, but I was expecting you to help me solve it 😂😂

[@Djrarone]

👌😂

[@SpirosGRTaxi]

I had the same problem on my Peugeot 301 BHDi 1.6 99ps, the car has 400K (new car). Some day leaking and I use Jlm radiator stop leak and all it's OK!(I use only the blue/green antifreeze original from Peugeot)

[@Djrarone]

Try to check the waterpump to see if its leaking, even small this could explain

[@RC-ph7qs]

I have this issue. I have to top up the coolant almost every week and no aparent leaks to find. I am going nuts.

[@peugeoton4033]

So you have another problem....antifreeze leak. I don't have an antifreeze leak.

[@RC-ph7qs]

Ok coolant/antifreeze? Whats is the diference?

[@peugeoton4033]

@@RC-ph7qs The difference is that my level is changing, but I don't need to top it up. Sooner or later, the level returns to normal, and then jumps again....

[@RC-ph7qs]

Ok. Have you found an answer yet?

[@peugeoton4033]

@@RC-ph7qs Yes. I think a video will be released soon.

[@neo-pp1nx]

İk heb een 1.5bleuhdi ik heb ook hetzelfde probleem. İk denk dat het oliekoeler is. Deze ligt achter het dpf en daarom is het niet zichtbaar.

[@andreigabriel9472]

I have the same problem with 1.5…

[@ndzone_TopG]

Me too (with the 1.5). It's been 4 years and this sh*t company is still not able to find the origin of the problem on it's own vehicle. Never again I will buy Stellantis!

[@liviustefan1610]

I have the same car,the same issue ! If someone have a sollution for this,i am interessed to know ! thank you for your post.

[@brankomandic33]

I had egr valve leak.

[@peugeoton4033]

leakage from the USR heat exchanger. To be precise, it is not a leak, but gases from the EGR heat exchanger (as a rule)

[@PaulWilliams-xz3mz]

Can i add water to it if its a bit low? Sorry not a car man😂

[@peugeoton4033]

If it's a one-time thing, that is, a one-time thing, for example, you need to get somewhere and it's warm outside (plus temperature) that's how it can be done. But you can't do this all the time - there will be problems...and with the radiator of the stove, and possibly with a pump .....water, this is as an emergency measure.

[@PaulWilliams-xz3mz]

@@peugeoton4033 thank you so much for the reply, great help, thanks 👍

[@srdjanradulovic168]

Waterpump