Mitsubishi Lancer Engine Problems

Your Lancer uses a timing belt which is made from a rubber compound and drives the camshaft. This makes for a cheaper engine to build and potentially quieter running, but it also means that the belt has to be changed periodically to prevent it snapping in service.

Mitsubishi recommends a belt-change interval of 100,000km. The advice of most mechanics it to replace the water pump at the same time since this part of the engine will be apart to change the belt anyway. It’s a lot cheaper to do both things at once, rather than open the engine a second time to change a water pump at a later date.

A thermatic fan is designed to run only when it’s needed. As the name suggests, it should switch on when the engine attains a pre-set temperature and then turn off below that temperature. It’s a way of having the engine run at a more constant temperature as well as saving the power normally used to run a fan that isn’t needed the whole time. Sometimes, a second electric fan will cut in when you turn the air-conditioning on, but the short answer is no, a thematic fan should not run all the time.

It’s unlikely, more likely it’s a problem with the throttle body. Have it cleaned out and the idle reset if needed.

You should have the recall work done; your car is unsafe and dangerous with the old airbag. Make sure they understand your concerns when you take the car in, and check it closely when you get it back.

I’m guessing they made a mistake when replacing the airbag the last time, I would hope they won’t make the same mistake again.

All you have is your gut feeling; you need to have something more concrete than that if you hope to make any progress with the dealer. They clearly haven’t been able to find anything wrong with it when they have checked it. I would start by checking the fuel consumption. Measure it; if it’s substantially higher than it should be (7.2 L/100 km average, 5.7 L/100 km country, 9.8 K/100 km city) then that tells you there is something wrong. Then I would find a flat section of road where you could safely measure your car’s 0-100 km acceleration time, which should be around 9.5 seconds. If it takes significantly longer than that it’s also an indicator that something is amiss. With that info you can decide for yourself if there is a problem or not, and if the numbers suggest there is you have something to show the dealer.

It has a timing chain, so there's no need to change it.

Regardless of the engine work, the Viva is not a good car. For similar money, in a small wagon, I'd go every time for a Mitsubishi Lancer.

It would be wise. Belts are usually changed either by reaching a specified mileage, or at a specified time limit. Your car hasn't yet reached the mileage, but it has passed the time limit. It's not worth taking a risk on the belt and potentially suffering major engine damage.

No, it has a chain instead of a belt and there's no need to change it as there is with a belt.

While it's past history now, you shouldn't have accepted the car when the dealer hadn't done what they'd agreed to do. That should have been fair warning that the dealer wasn't as good as his word,  and you should have walked away. And never, repeat NEVER, do verbal deals. The rattle could be pre-ignition, but you need to have a mechanic check it for you, and a specialist in Evos would be  preferable. As for the dealer, you need to persist and show that you won't go away. Also consider going to the state consumer affairs people.