Ford Focus 1.6 Petrol Timing Belt

Question

I brought a ford focus 1.6 04 plate with 154k on the clock (got it cheap!). It is up to 155k now had it about 3 months.

My mechanic advised me to change the timing belt and water pump asap which I will do as I trust his advice however I need to wait until I have the money.

I've been reading up quite a lot and the recommended mileage for this change is 100k, most people say get it changed between 70-80k to be safe.

Therefore in my head I'm thinking to make it to 155k without the belt snapping surely this means it must have been changed at some point or it would have gone already by now right?

I'm hoping to get it done in a week and a half however I'm getting paranoid every time I drive the car now, plus I need to do about 400 miles this weekend which is getting me worried.

So I guess my questions are:

Do you think the belt has been changed in its life (we have no history of the car)? Is there any indication it could be on its way out (noises, vibrations, etc.)? What am I expect if it does snap (how can I avoid crashing if it goes)?

Thanks in advanced!

Answer 1

You can have a look at the condition of the belt to gauge its condition. But you'll need to have seen quite a number of timing belts to be able to tell.

The risk is that when a timing belt snaps, it damages your valves and pistons too. To fix that will require the engine be taken apart and the damaged parts replaced. It's not a cheap thing to do. Timing-belt related damage can cost anything from $1000 to $6000 depending on the car and the extent of the damage.

If you're worried about it, don't drive fast and don't rev your engine higher than needed. Keep it under 3500rpm. And try not to vary the RPM quickly. E.g. don't down shift suddenly and don't accelerate fast. Any time there's a sudden change in RPM, the timing belt experiences a shock, which could turn out to be the shock that finally snaps it. Smooth is the word.

Answer 2

The key to your mechanic's response about changing the timing belt and water pump "now" is that you have no real indication of the maintenance history of the car. You don't know if it's been changed or not. A timing belt could last for that long, but who knows. The mechanic is giving sound advice because he's trying to help you protect your interests.

Do you think the belt has been changed in its life (we have no history of the car)?

It probably has been changed, but you just don't know without the maintenance records. Only if you trust the records provided would I not consider changing it out, but might just do it for piece of mind.

Is there any indication it could be on its way out (noises, vibrations, etc.)?

Usually when a belt goes, it goes without warning. You may be able to pull the cover and see if there is any fraying or wear, but usually you won't see it. I've also seen where the belt teeth become separated from the belt itself, but usually the belt becomes stretched enough for the teeth to jump one or more positions, which fouls the cam timing.

What am I expect if it does snap (how can I avoid crashing if it goes)?

I'm not sure of your particular vehicle, but most newer vehicles with a timing belt are interference motors, meaning that the valves and pistons share the same space inside the combustion chamber, but do it at different times (as a result of valve timing). When the belt breaks or skips teeth, the pistons and valves can come into contact causing major damage, which as Juann alluded to, can cost lots of money.

Just to make you a little more worried, the belt can slip or break at any engine speed. When its time is up, it will happen. The only thing you can do about it is to change it out and be done with it.

As an aside, you mention most people suggest doing the maintenance every 70-80k. With a standard belt, most manufacturers have a 60k mile replacement. Some newer belts are made with Kevlar which then has a 100k change interval.