Timing (cam) belt question !

Question

This question concerns a 1999 UK Ford Focus 1.8 Petrol model.

I know from various sources how bad it is to get engine oil etc onto the timing belt and tensioner etc, e.g. from the Hayne's manual and various internet articles.

On the one hand the thought haunts me that there could be oil on my timing belt from a rocker cover gasket oil leak and so this could reduce the life of the belt or if it slipped on the idler pulley could cause great engine damage. On the other hand I think about all the car/vehicles on the road today that have timing belts and especially the older ones which are probably contaminated with oil etc from leaks of one kind or another but they don't seem to worry about the financial consequences of a belt failure.

What are your opinions on this quandary ?

Answer 1

if it is not a bad leak you could wash it off with brake cleaner ,that will not harm the belt then you can check a week later to see where the oil leak is coming from if ther is one

good luck h

Answer 2

the biggest concern is whether the engine is interference or not.  by this i mean, will the valves hit the piston, if the belt breaks and the timing gets out of whack.  if it is a non interference engine, you could run it, till the belt breaks, then reset the timing and put on a new belt.  if its the other way, the engine is going to be junk, when it starts to destroy itself.

Answer 3

It depends on the amount of oil/contamination, unless it is excessive dont worry to much about it, most cars have some contamination on the belts/pulleys.   Rich  ,30 years mechanic,

Answer 4

A study it to cambelt failure some years ago showed that most cambelt failed through under tension - it allows them to rattle around and shears the teeth off. Over tension was nexts followed by oil contamination, and finally "Others".

My 2.0 TD Toyota should be done at 100k Km, I changed it at 100k miles. There an no oil leaks.

You could take the belt cover of and have a look and see if it is covered in oil.

If it such a concern just get on and sort your oil leak and fit a new belt; problem gone away.

Answer 5

If the tensioner is working as it should - ie keeping the belt under tension - it should not slip as it is a toothed belt. Oil contamination will lead to reduced life though. The trouble with timing belts is that they are typical of a number of modern mechanical 'improvements' - one step forward and one and a half back!  The old timing chains would wear and hook the sprockets but long before they would get near breaking point they would be so noisey you could not ignore them. The Rubber and cord Timing belts are much quieter but can snap without ANY warning, with sometimes catastrophic consequences for your engine.

You might consider getting hold of a Haynes manual and reading up on how to change the timing belt - it is not actually that difficult if you take it slowly step by step and the belt ite-self is pretty cheap.

I live in the country and cannot get to work by public transport so for me, it is always a case of, if in doubt, replace it.