The timing belt advice thread
Discussion
Last week I was discussing my small coolant leak, which seemed to be coming from a bottom hose.
Well today, I had a good bonding session with my roadster. The plan was to
- Fit an extra ILM front brace
- Remove my A/C
- Fit new PAS and Alternator belts
All this went well. But I have now found that my water leak is not coming for a pipe. Its emanating from directly above, and behind, the main crank pulley. AKA - where the waterpump is.
So, nuts on the road. While the cars in bits, I'm gonna order a timing belt kit, and waterpump, and do it myself.
I've read the miata.net guide, and I have Rods book (very good buy btw!).
What do I need to order in, to make this a painless job.
So far I have thought of
Belt itself
Pulleys
Cam cover gasket
Waterpump
Waterpump gaskets
What else should I do at the same time?
As the Rads coming out anyway, I'm contemplating getting a full hose kit aswell....
Any tips on the general timing belt issue?
Well today, I had a good bonding session with my roadster. The plan was to
- Fit an extra ILM front brace
- Remove my A/C
- Fit new PAS and Alternator belts
All this went well. But I have now found that my water leak is not coming for a pipe. Its emanating from directly above, and behind, the main crank pulley. AKA - where the waterpump is.
So, nuts on the road. While the cars in bits, I'm gonna order a timing belt kit, and waterpump, and do it myself.
I've read the miata.net guide, and I have Rods book (very good buy btw!).
What do I need to order in, to make this a painless job.
So far I have thought of
Belt itself
Pulleys
Cam cover gasket
Waterpump
Waterpump gaskets
What else should I do at the same time?
As the Rads coming out anyway, I'm contemplating getting a full hose kit aswell....
Any tips on the general timing belt issue?
Glad to see you've included the pulleys!
I'd just add threadlock to that little lot, worth the extra security.
I have a 1.8 waterpump I ordered in error from MX5 parts, it's the genuine Mazda one too. (I've got a 1.6...)
Did you have antifreeze on the list of things to get? May also be worth ordering the small tensioner spring too, think its dirt cheap - it only initially tensions the belt then you just tighten the adjuste bolt.
I'd just add threadlock to that little lot, worth the extra security.
I have a 1.8 waterpump I ordered in error from MX5 parts, it's the genuine Mazda one too. (I've got a 1.6...)
Did you have antifreeze on the list of things to get? May also be worth ordering the small tensioner spring too, think its dirt cheap - it only initially tensions the belt then you just tighten the adjuste bolt.
Yup, I ordered the kit which comes with the pulleys, the tensioner spring, etc. Anti-freeze ill pickup tomorrow morning from my local.
Today I've removed the cam cover, crank pulley etc, radiator, a/c radiator, both fans etc. also removed the charcoal canister.
The weight saving from ditching the AC is unreal!
Might keep both fans for a bit of extra cooling power.
Parts *should* arrive tomorrow, quick bike ride to pick up some liguid gasket and threadlock, and ill be off.
I've painted up all the timing marks with white acrylic paint, looks quite neat
and got a timing light so ill set it up to 14' BTDC aswell.
Today I've removed the cam cover, crank pulley etc, radiator, a/c radiator, both fans etc. also removed the charcoal canister.
The weight saving from ditching the AC is unreal!
Might keep both fans for a bit of extra cooling power.
Parts *should* arrive tomorrow, quick bike ride to pick up some liguid gasket and threadlock, and ill be off.
I've painted up all the timing marks with white acrylic paint, looks quite neat
and got a timing light so ill set it up to 14' BTDC aswell. Right guys. It works 
Car is still on the stands, so I can check it for any slow leaks etc tomorrow, if its still fine, then stick the undertray back on and im done.
Its took about 10 hours. I worked slowly and carefully. I also did a lot of cleaning of parts, degreasing, touching up a few bits of paint etc, that you wouldnt get done with a garage job.
A few extra things needed over and above the standard toolkit. -
Threadlock
24mm box Wrench (I didnt have one this big, had to bike it to the shop)
Large adjustable wrench
Breaker bar
White acrylic paint and a tiny brush.
Lots of brake cleaner (for all the extra cleaning of parts)
Strobe timing gun
Silicone sealant
New parts -
Timing belt
tensioner pulley
idle pulley
Crank oil seal
Camshaft oil seals
Waterpump
Alternator belt
PAS belt
Plus associated gaskets/seals etc
I have to say - it was suprisingly straightforward. The little Mazda engine is bolted together very well. Considering mines 15yrs old, it was clean, everything came apart easily, nothings seized or rounded. No silly bolt sizes or shapes (previous peugeot owner!).
Of course, being a longitudinal engine, access is much nicer than a modern euro-box.
The white paint is for marking up the pulleys and timing belt. You can then use the old timing belt, once removed, to copy the marks across to the new one. Then its a doddle to get it fitted correctly on the right teeth.
The 24mm and adjustable are for holding the camshafts strady while you undo the Cam pulley retaining bolt, in order to replace the cam shaft oil seals.
Rods manual states that radiator removal is optional. Just do it. Gives much more room and its only about 4 bolts.
You may aswell do the whole lot as I have listed up there - parts cost is about £120. Your saving a HELLA lot of labour charges if you do this yourself! And preventative maintenance is a good thing.
Once started up, it ran a bit lumpy for a few minutes, till it sorted itself out and the fluids got round. Then I reset the idle, and used a timing strobe to set the ignition to 14deg BTDC. Idles rock solid now.
In answer to the question posed on m.net - "should you change your timing belt yourself" ?
Well - I'm no expert, Purely self taught. Done brakes, oil changes, services etc before. I didnt struggle. I have nothing more than a good, basic set of tools. Nothing specialist is needed really. If your confident, methodical, and careful, its well within the realms of the home mechanic.
Car is still on the stands, so I can check it for any slow leaks etc tomorrow, if its still fine, then stick the undertray back on and im done. Its took about 10 hours. I worked slowly and carefully. I also did a lot of cleaning of parts, degreasing, touching up a few bits of paint etc, that you wouldnt get done with a garage job.
A few extra things needed over and above the standard toolkit. -
Threadlock
24mm box Wrench (I didnt have one this big, had to bike it to the shop)
Large adjustable wrench
Breaker bar
White acrylic paint and a tiny brush.
Lots of brake cleaner (for all the extra cleaning of parts)
Strobe timing gun
Silicone sealant
New parts -
Timing belt
tensioner pulley
idle pulley
Crank oil seal
Camshaft oil seals
Waterpump
Alternator belt
PAS belt
Plus associated gaskets/seals etc
I have to say - it was suprisingly straightforward. The little Mazda engine is bolted together very well. Considering mines 15yrs old, it was clean, everything came apart easily, nothings seized or rounded. No silly bolt sizes or shapes (previous peugeot owner!).
Of course, being a longitudinal engine, access is much nicer than a modern euro-box.
The white paint is for marking up the pulleys and timing belt. You can then use the old timing belt, once removed, to copy the marks across to the new one. Then its a doddle to get it fitted correctly on the right teeth.
The 24mm and adjustable are for holding the camshafts strady while you undo the Cam pulley retaining bolt, in order to replace the cam shaft oil seals.
Rods manual states that radiator removal is optional. Just do it. Gives much more room and its only about 4 bolts.
You may aswell do the whole lot as I have listed up there - parts cost is about £120. Your saving a HELLA lot of labour charges if you do this yourself! And preventative maintenance is a good thing.
Once started up, it ran a bit lumpy for a few minutes, till it sorted itself out and the fluids got round. Then I reset the idle, and used a timing strobe to set the ignition to 14deg BTDC. Idles rock solid now.
In answer to the question posed on m.net - "should you change your timing belt yourself" ?
Well - I'm no expert, Purely self taught. Done brakes, oil changes, services etc before. I didnt struggle. I have nothing more than a good, basic set of tools. Nothing specialist is needed really. If your confident, methodical, and careful, its well within the realms of the home mechanic.
Edited by snotrag on Friday 24th April 22:47
Edited by snotrag on Friday 24th April 22:49
MX-5 Lazza said:
It does make a difference.
It makes more of a difference on a 1.6 but the gains are still there on the 1.8.
Some have gone to 16BTDC without issues - I've even heard of 18BTDC but that would need higher octane fuel which is a waste without FI. Personally I'd stick with 14BTDC.
Excuse my ignorance, but I've only just spotted this. Does this timing tweak result in more power? If so, are there any disadvantages? And finally, will it work on a 1.8 VVT engine?It makes more of a difference on a 1.6 but the gains are still there on the 1.8.
Some have gone to 16BTDC without issues - I've even heard of 18BTDC but that would need higher octane fuel which is a waste without FI. Personally I'd stick with 14BTDC.
On any engine having the timing advanced as far as you can go without getting knock (pre-ignition, pinking - all the same thing) will result in the best power.
Advancing the timing from the stock 10btdc to 14btdc will give more mid-range power and better throttle response. Some say that it results in a slightly lower top-end power but I haven't seen any dyno-graphs to prove this.
On a 1.8 VVT car the timing is fixed so you don't have this option.
Advancing the timing from the stock 10btdc to 14btdc will give more mid-range power and better throttle response. Some say that it results in a slightly lower top-end power but I haven't seen any dyno-graphs to prove this.
On a 1.8 VVT car the timing is fixed so you don't have this option.
good writeup,done my cambelt twice now ,first time did just the cambelt ,3 months later water leak !!so had to do it all again ,as above if cambelt is due to be changed do the water pump at the same time (even if its not leaking it may soon be )and the cambelt tensioners as they make a really annoying rumble when they are knackered .tension spring is a must as the old spring wont apply the right tension to a new belt .
top tip from mechanic friend if you can't undo the bottom crank pully bolt get a long tube over your socket bar ,reach to the ignition key and give the starter a quick touch (hold tight to bar !!) works a treat .
top tip from mechanic friend if you can't undo the bottom crank pully bolt get a long tube over your socket bar ,reach to the ignition key and give the starter a quick touch (hold tight to bar !!) works a treat .
I'd say no. As another tip, on a 1.6, don't remove the lower crank pulley bolt (the big one) - but take the 4 small bolts from around it, this will allow the accessory belt pulley to be removed without disturbing the crank bolt but still allow you to take the timing belt off.
Early 1.6's had a crank nose length that was marginal, disturbing this has the potential to cause the pulley to move enought to wreck the keyway and mess up the timing, the crankshaft and world peace.
For the four bolts, just put it in gear (ideally not jacked up so that the car can't be pushed off any stands at the front). 5th is best.
Early 1.6's had a crank nose length that was marginal, disturbing this has the potential to cause the pulley to move enought to wreck the keyway and mess up the timing, the crankshaft and world peace.
For the four bolts, just put it in gear (ideally not jacked up so that the car can't be pushed off any stands at the front). 5th is best.
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