Typical Cost: Medium
Mobile Repair? Yes
Typical Lead Time: 24 - 48 hours due to length of repair time
The timing belt (or cambelt) is a toothed, strengthened rubber belt used to rotate the camshafts at the correct time with the pistons, hence “timing belt”.
The timing belt has a specific number of teeth that are matched in perfect harmony with the cog on the crankshaft and the cogs on the camshaft(s). This is set to rotate the camshaft so the valves open at the precise time they are meant to in correlation with the rise and fall of the engine's pistons.
The timing belt is usually held in place by a tensioner and a guide roller.
On many engines, the water pump is driven by the belt as well. If this is the case, it is imperative to have it replaced at the same time. There are two reasons for this, firstly, the water pump is a pulley and bearing that forms part of the circuit the belt travels around and should it fail, then the belt will come off and that is the same as it breaking. Also, water pumps are prone to seizing, which again will break the belt.
The second reason is that should the water pump fail (and not damage the belt etc) and require replacing, then the timing belt would have to be renewed at the same time, so its best to have a new one fitted as a preventative course of maintenance.
Most mechanics will not carry out the work unless the pump is replaced in the situation as they know the consequences!
Under no circumstance should a timing belt be put back on once it has been removed, no matter how recently it was done. Any small nicks or damage to the belt during the process could be catastrophic - so no, for the cost of the belt itself its not a risk that any mechanic would take
The timing belt is hidden from view and protected by a cover in the vast majority of cases.
Sadly in 99% of cases you will only know if there is an issue with the cambelt when it breaks! This can occur at any time, at any speed and usually at the most inconvenient time and place. This is why manufacturers give recommended replacement intervals, both in terms of age and mileage. It is preventative maintenance that should never be overlooked.
There is very little pre warning that a timing belt is about to break, it will simply snap. This can occur at any time, from initial startup to cruising on the motorway. Whatever the circumstances, the chances are that your engine's pistons will collide with valves that are operated by the camshaft. The result of this collision depends on a number of factors, but the valves, rocker arms, camshaft, pistons, even the cylinder head itself etc all could suffer damage.
The only way to fully understand what damage has been caused is to remove the cylinder head from the engine and physically see what the resultant collision has caused.
Therefore, if your timing belt has snapped, we cannot quote for how much it will be to repair the damage, as we simply will not know at that stage. What we can quote for though, is the work required to strip off the cylinder head in order to provide a quote on the damage caused. If this is the case, you will need to contact our Mechanics in Residence team for a custom quote.
Each manufacturer will give a recommended replacement interval for the timing belt on its vehicles. This information is usually available in the Owner Handbook, however if you do not have this in your possession, we are happy to advise accordingly.
If you have purchased a second hand vehicle and it has no timing belt change history, such as a garage invoice, then it is important to err on the side of caution and have it replaced as soon as possible,
Replacing a timing belt is a routine repair for all mechanics and can be done both kerbside as well as in the workshop, providing it is safe to do so.
Whilst there are variations between manufacturers, the basics are pretty similar.
The mechanic will;
Unless otherwise stated, the quote for your timing belt replacement will cover;
Timing belt replacement
The cost of a timing belt replacement depends on your car and what parts your car's manufacturer recommends.
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Timing belts come as a kit with the guide(s) and tensioners, and these will be fitted at the same time.
In the unlikely event of a timing belt failure, or indeed if the guides or tensioner should fail, then the resultant damage will be covered by the warranty.
Under no circumstances can a belt be refitted. Any nicks or damages done to the belt during its removal can manifest themselves into a snap at any given point.
If the water pump is driven by the timing belt, then it is also an important bearing and cog on the circuit. Therefore it is considered as vital as the guide(s) and tensioner and msu be replaced. Mechanics will not consider replacing a timing belt that has a water pump on it, without changing it.
The other reason is that should the water pump fail, then the whole timing belt job has to be done again with a new belt.
If this is the case, there is no need to do so, however if you wish, we can of course do it, but there is little cost saving in doing so.
The auxiliary belt will need to be removed to carry out the work, so it is an ideal time to change it for the just the cost of the belt as there is no additional labour. It isn’t imperative though, so you do not have to.
No, we will not fit customer supplied parts unless they are a brand new item, purchased from a dealership with the receipt as proof of purchase. There is no flexibility over this due to insurance and warranty issues.
Timing belts do not give any signs of wear, well not often anyway! Therefore as the work is preventative, it is highly unlikely that a mechanic will say it doesn’t need changing.
Timing chain replacement
Auxiliary belt replacement
Water pump replacement