I bought a car that seemed cheap for what it was. Turns out is was unpopular because of the timing belt in oil. Can't say I've had any issue with it though (with basic maintenance) but it's only 8 years old.
Now interference engines detonating when the timing belt breaks isn't new, but putting a belt in a bath of dirty and burnt oil that makes it a mess and expensive to replace and basically impossible to inspect is pretty silly. A chain would not have had such problems and become an efficiency and running issue from a stretched chain instead of sudden and catastrophic failure of a broken belt.
It also has the problem of rubber belt pieced clogging up the oil system.
Its fine for people that get all the regular maintence and oil changes strictly on time. But not everyone does it so diligently. And if you buy it as a random used car you have no way of really knowing how good that belt is without a list of every oil and belt change and how hard they drove it.
Needs changing at 100,000 to 150-000 miles or every 10 years.
The 10 year service is a spendy one.
Ford's recently designed engines were designed with a timing belt internally that operated in an oil bath.
They are currently walking that decision back and attempting to make it look as if it wasn't planned obsolescence (dry cambelt engines or proper timing chains means that the engine would last almost longer than the person who bought it if they did the regular maintenance. A cambelt that cannot be changed because its internal means that there is a limit to how long the engine would last.)
Is not designed by Ford. Those are (most probably) the same as the infamous Puretech motors developped by PSA. Is a Peugeot car disguised as Ford (or a Ford car with a Peugeot motor if you prefer). Several brands use it, under different names. Most probably they bought them under a big discount.
That motor was durable, tested and approved, But... Europe said: You must adjust this and that for the new legislation, and the change made a little bit of gasoline to mix in the oil and reach the belt. Problem: Gasoline eats rubber over time, and the timing belt is made of rubber.
The real problem was not so much that the timing belt could root entirely and break, leading to a catastrophic failure.
Much before that, the pump that sucks oil into the motor gets slowly clogged with rubber bits, triggering a "pressure oil failure" warning. Also the computer reacts to a slow lubrication reducing the power to protect the motor, so you have a car with random power failures and alarming warnings. If you ignore this, eventually the rubber dust accumulated could block entirely the oil from entering into the motor. And then your motor is destroyed in no time.
Nobody suspected that when Peugeot sold thousands of cars. A few years later, many cars that were still basically new, started to die or require expensive reparations. The makers warned on the manual that the belt must be changed often and this avoids entirely the problem. Second problem: Only car freaks follow the manual specifications. Every common owner expected the timing belt to last for the same as a traditional one (160,000 to 240,000Km or so), when it must be changed at 60,000 or so. Changing the time belt is not cheap and they ignored the warning as a grabbing cash trick.
For a while, common people were still buying cars with big discounts that mechanics didn't wanted to touch with a teen foot pole. Spanish influencers started to rebrand the pure-tech motors as pudre-tech (in Spanish: it-rots-tech), and the term slowly reached the public opinion.
Even following the specifications, you are stuck with a car that is more expensive to maintain.
Peugeot fixed the issue changing the belt material, but the reputational damage was done and was eventually absorbed into Stellantis, a superbrand created with Chinese, Italian and American investors.
If your car uses gasoil you don't have this problem. Only gasoline. Peugeot declared in jun 2026 that those family of gasoline motors are about to be finally discarded and replaced by a new motor (with a chain belt and designed for better integration with hybrid systems).
The surface-level problem, sure. The root cause is that the "engineers" (and I lose that term loosely) decided that running a rubber belt in an oil bath internal to the engine was a good idea.
It obviously isn't a good idea, even if you could guaranteed that petrol will never mix with the oil. In the best case scenario, when the belt starts degrading (because all belts degrade), you're throwing pieces of rubber into the oil pump.
Even in the best-case scenario, the effect of that design was to reduce the cap on engine life.