My mk2.5’s cambelt was changed at 56,000 miles. I’ve just now crossed 110,000 miles so I guess the cambelt is due.
How long can I safely leave it before changing it? It seems like I’m throwing money at my car left right and centre at the moment and I don’t want to spend another £250 on a cambelt right now.
When would be safe to leave it?
Does it even matter if I leave it? I have read that because it’s an “non-interfering” design or something that if the cambelt fails, it doesn’t affect any other components. So theoretically could you just run the car until the cambelt dies, then tow it away to a garage and fix up a cambelt like normal replacement?
Anyway how long can I leave it? Until next year? later this year? thanks.
I could be wrong, but the vvti engines on the mk2.5 are interference engines, so the valves could hit the pistons, however I think that mk1 and mk2 are none interference engines.
So personally I would not risk destroying the engine and would change it sooner rather than later. Where as on a mx1 you could risk breaking down when it snaps without any real issues.
The cam belt is an easy change on a mk2.5, buy a kit and do it yourself. If you cut the old belt length ways, you can leave half of it in place when you put on the new belt so you don’t even have to worry about timing, once the new one is on half way cut the second half of the old belt off and push the new one fully on. Watch Car S.o.S as Fuzz does this all the time. Makes changing a belt really easy.
Ian do not watch a TV programme and then say the cam belt is an easy change. It is not in the least an easy job.
Unless that is you have done it many times and you are offering the original poster to do the job for him. I have one say 6 MX5 cam belt changes, therefore no great expert.
It is a pain of a job and at that age of car, nuts and bolts are rusted up on many occasions and unless you are a mechanic it takes a good day to do and many garages will charge you 6 hours rather than the 3 or 4 hours that people say they can do it in.
Some garages will charge less.
To the original poster it is your risk and some cosy words from someone on the forum saying it will be OK not to change it are just that cosy words.
You are aware of the manufacturer’s recommendation.
Your car, your risk do not say “I did not do it because someone on a forum said it would be OK”.
Thanks. I just don’t know how risky it is. I assume the vast majority of cambelts would last far longer than 54,000 miles so I’m not too worried… just a matter of at what point does it really matter.
I’ve got to spend £250 on rust in a few months time once I have the money, so it’s yet another thing I gotta do.
And yeah, to your first point - I have never done any mechanical work on a car. Would much rather leave it to professionals who know what they’re doing.
VVT is no n interference also so no need to change immediately.If it breaks it just means you will be stuck on roadside but no damage to engine .Fit new belt and pump and away you go.It is good advice to change it when you get chance though
And my daughter’s first car was a Corsa and we were assured it had had a cambelt change. It was a costly repair when it went long before it was due for replacement according to the info from the previous (rogue) seller!
Mk 2.5 is a non interference engine. All Mk2.5’s are now at least 12 years old. I was assured the cambelt is replaceable at mileage (in the book) either 50 or 60K miles - my cars on the road at the moment, so can’t consult or confirm it.
However, a long thread on here several years ago convinced me cambelts need replacing every six years, as the maker (Gates) only guarantees them for this period. Same period on any car, with a cambelt. Mileage is a figure, so it’s either one or the other, whichever comes first. My view is a cambelt is a ‘wear and tear’ item, and Mazda will not replace it under either figure regardless of makers guarantee. Same with other drive belts, they too may need replacing. A set from MX5 parts is a reasonable price, but you need a good mechanic to fit them.
Depending where the belt snaps, you WILL come to a sudden stop, not good on crowded roads, and possible suicide on motorways. If you declutch it fast enough, you may have enough momentum to get off the road, though if it’s the middle or fast lane on a motorway you won’t get time to do that. I wouldn’t risk it, regardless of cost. If we knew where you live (roughly) someone can suggest a good garage where it won’t cost you an arm and a leg to replace, If my memory is still good, I think I’ve seen £180 quoted. As the water pump needs a cambelt removal to replace, it’s common practice to get that done at the same time, especially at over 100K miles.
I cannot imagine cutting a cam belt in half, 360 degrees, so I take that with a pinch of salt. Cambelt changes need correct alignment of both cams and flywheel, which means you need a special tool to lock everything in place before starting the job.
So - another expense, but hey, it’s now an older car, and we all expect that. Your life is worth more.
From personal experience, I can say that there’s no great difficulty in cutting a cam belt lengthways in the way suggested. This type of belt consists of loops of a strong synthetic “twine” encased and joined together side by side by rubber. I’ve done it using a “Lino” knife, which has a blade like a Stanley knife with a small hook in it. Over the last two years I’ve designed and built my own supercharger conversion on one of my other cars and consequently had a little trial and error with belt circumference and pulley types and had a few spare belts which I’ve used for other purposes. It’s easier to cut between the loops than it is to cut the belt across them.
The “David Manners” cam belt kit in my garage will be fitted by myself on the driveway as soon as the weather is half decent. I’ll probably use the method exactly as described above. If I don’t find it is possible or safe to do it in situ on the NB, there’s another method of locking the cams, using two spanners on “flats” on the cam shafts themselves and locking them together.
i forgot to say that cam belts and the drive belts I use for my supercharger are of similar construction, although the cam belt has “teeth”.
I had a Gates belt snap at 46k miles/ 4 years old, outside lane of the M25. Once I was able to realise the engine had stopped (and it does confound the senses at that speed), I was luckily able to coast to the hard shoulder, stopping just short of a junction.
Gates sets the warranty as being the OE Recommended Replacement Intervals. In documentation they also recommend 72 months, or whatever comes first. But in their warranty terms, they do not mention duration. Interestingly, the the 2005MY Miata, with the same part numbers as the ROW, they have two different intervals, depending on geography; in California, it is 105k miles (I think there is a regulated 60k mile inspection, but not change) and 60k mile for the rest of the US, which covers an exceptionally wide range of driving conditions. For the 2004MY, just 60k miles is specified, no change in part number.
Not sure about the VVT 2.5s but if the top end is like the 1.6 its a pretty easy job to lock the cams using a pair of adjustable wrenches and a g-clamp. The cams have a hexagonal section specifically for that purpose.
I tried this once, at the regulated 70.0mph, and ended up with a mechanic sucking through his teeth, saying I needed a new negine. I told him it was a non-interferance engine, he said, book says otherwise, you need a new engine. I said just put on a new belt, mechanic said ok, but you need a new engine. Car started up, ran fine, I said, told you so, mechanic now said,. “ah, but your engine is an import engine” .
Had my belt done at the end of last year, the belt that came off it (At 111,000 miles) was a very, very haggard Mazda OEM belt, the rubber was cracked and crumbly. Was it the factory fitted one? Possibly…
