Cam Drive Timing Belt Replacement

Technical Area Routine Servicing
2

I don’t know anything about the MK3 MX5 I bought recently.

On a Vauxhall Vectra I had the cam drive belt broke and the pistons bent all of the 16 valves - a very expensive repair.

Does my MK3 have a similar belt that needs to be replaced at particular mileages? I believe some car have timing chains which don’t need replacing.

When I look under the bonnet I can see a belt. Is this simply a less critical belt which won’t cause any engine damage if it breaks?

 

I would like to fit a tow bar onto my car to fit a cycle carrier. Is there a tow bar available for my MK3 MX5?

 

3

The Mk3 is chain driven cam. I do not think there are tow bars for any other than mk1.

4

The MK3 has a ford(Duratec) engine I think. As well as cam chain, rather than belt this engine is interference, so a broken chain will impact valves and pistons.

MK3 towbar may be available from the states or get one fabricated.

Here you go…

http://www.ebay.com/itm/Curt-Class-1-Trailer-Hitch-11028-for-Mazda-MX-5-Miata-Convertible-/140902591607?hash=item20ce72ec77:m:mFTDeb4ZpGk6QMdMpyNUc-A&vxp=mtr

So in the states its known as a trailer hitch:-)   

5

Thanks for your replies.

Do I need to get the timing chain replaced at a particular mileage before it breaks?

6

The timing chain has an automatic tensioner and should last for the full life of the engine.  There’s nothing in the service schedule about replacing it.

 

PS   The engine is actually a Mazda MZR engine, not a Ford design, though Ford have the rights to manufacture it as a ‘Duratec’.

7

Here’s a bit more info for interest only

https://en.m.wikipedia.org/wiki/Mazda_MZR_engine

Barrie

8

Well I can see the irony in that.

 

 

9

Should I have said “…and will comfortably outlast the engine”?

10

LOL

Timing chains usual reason for failing is oil related - poor quality, low level or not changed frequently enough!  

 

 

11

Its Interesting that if you use the USA link for the Towbar and in the Car make and model box, for model it gives a choice of MX5 Miata or MX5 if you choose MX5 it states the Towbar is NOT suitable for this model

12

Without searching I can’t be sure, but I recollect reading something about MK1’s being fine with a towing bracket but “illegal” on later models? It was on MX5Nutz that’s for sure, some while ago. Makes some sense where the USA will have different legislation I suppose? Don’t ask me why it would be illegal, I’ve no idea.

Barrie

 

EDIT: Couldn’t resist to do with type approval

http://www.mx5nutz.com/forum/index.php?showtopic=105313&hl=+towbar%20+on%20+mx5

13

Your edit beat me to it - Type approval as in Catalytic converters.

ironic that the kings of safety(Nader et al) allow towbars on their miatas   

14

 

You don’t need a tow bar to carry cycles, take a look at this http://www.mx5parts.co.uk/boot-mounted-cycle-rack-models-p-3196.html

It will hold up to two bikes and no need for a tow bar.

15

Over the main drive belt it is a chain. The belt you see is the Aux belt, it is not due for replacement in any service schedule at all.

But…(there always was going to be)…

Whilst I have never heard personally of the aux belt snapping it does drive the water pump for the engine, so if it snaps there is going to be lots of crying. Also it is worth considering replacing the idlers & tensioner whilst it is off. 

There has been some issues (common among the MZR engine range) of the automatic tensioner…