replace drive belt and water pump + fuel filter

Started by Mollydog, January 9, 2023, 07:01

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Mollydog

Our MR2 has just come up to 89K miles, maybe it's time to have the drive belt changed?

I would normally be looking at doing this myself, seeing how the weather is and my garage isn't ready yet, I'm thinking of getting my local garage to do the work

We've owned the car since it was just over a year old (around 15 years ago) and in all that time we've not had the water pump or fuel filter changed, should I be getting Both of these done at the same time as the drive belt?

Call the midlife!

If by drive belt you mean the auxiliary belt then that's a 10 minute job on the drive.
Water pump swap with the engine in in doable but very fiddly due to the use of 3 or 5 different sized screws and a gasket seal that likes falling out just as you offer up the pump.
If it's not broken you could probably happily leave it for another 30 thousand miles without issue.
The fuel filter is in the tank and quite a labour intensive job unless you present it to the garage with all the internal trims removed and replace them yourself afterwards.
Again, if it's not giving you reasons to suspect it needs changing I'd leave it alone, it has a pre filter "sock" on the intake to strain any big contamination out.
60% of the time it works everytime...

Mollydog

Many thanks midlife, Yes the auxiliary belt, I thought it was called the driving belt, in this case I'll leave the water pump and fuel filter alone and wait a month or two till we get better weather and do the belt myself

Carolyn

Quote from: Mollydog on January  9, 2023, 08:31Many thanks midlife, Yes the auxiliary belt, I thought it was called the driving belt, in this case I'll leave the water pump and fuel filter alone and wait a month or two till we get better weather and do the belt myself

There's a 'how to' for changing the belt.
Perry Byrnes Memorial Award 2016, 2018.  Love this club. 
https://www.mr2roc.org/forum/index.php?topic=63866.0

Joesson

Quote from: Mollydog on January  9, 2023, 08:31Many thanks midlife, Yes the auxiliary belt, I thought it was called the driving belt, in this case I'll leave the water pump and fuel filter alone and wait a month or two till we get better weather and do the belt myself

As above, it's an auxiliary belt, (not a cam belt) , so when it does go there is not such an immediate consequence.

Dev

The water pumps that are integrated to the block of the car like the ones on our car are very reliable with no specific time frame for preemptive replacement. They have a weep hole that will leak fluid once the seals on the bearings give way to let you know its time for replacement which is a rare occurrence. 

 The fuel filter has a very large capacity. Some of the same ones used on other cars have gone hundreds of thousands of miles without a problem but there were a few that were reported to cause fuel cut at higher RPMs because they were clogged. I replaced mine at 130k even though I had no issues  but keep in mind if it's not done right you can experience leaking from the hoses as some experienced. There are plastic fittings that have to be carefully removed.
Probably best to leave it alone unless the car has a lot of miles.


shnazzle

Quote from: Joesson on January  9, 2023, 14:11As above, it's an auxiliary belt, (not a cam belt) , so when it does go there is not such an immediate consequence.
Except for slapping around your engine bay and breaking some plastics as it does :(
Been there
...neutiquam erro.

Dev

Quote from: shnazzle on January 10, 2023, 17:39Except for slapping around your engine bay and breaking some plastics as it does :(
Been there

 One of our local members had that happen to him at night. Instead of pulling over he kept driving since he was not that far from his home which was a big mistake. The car overheated.  He got the belt replaced the next morning and all seemed fine as he met me for lunch regaling his experience. I let him know that he could have warped the block which he dismissed since the car was fine. As we were leaving I get a call from him telling me to come back because coolant leaked profusely from the head gasket. 
 
  I also do not think it's an immediate consequence but if it happens you need to watch the temps and then find a place to safely pull over. 





Joesson

#8
Quote from: shnazzle on January 10, 2023, 17:39Except for slapping around your engine bay and breaking some plastics as it does :(
Been there

Can't argue with experience.
My experience with belts, from back when they were Vee shaped and drove a dynamo and water pump, that I can't recall a significant problem with.
Toothed cam belts, that work until they don't and then there is a symphonic "warning" noise that heralds varying degrees of costly repair.
I have replaced my 2's Vee grooved drive belt, because of age and I do like to be able to drive home on the ( too few) occasions I use the car, but I wasn't aware of the potential for collateral damage.
We all are know though thanks to Patrick and Dev.

Joesson

#9
@Dev said:
they (water pump) have a weep hole that will leak fluid once the seals on the bearings give way to let you know its time for replacement which is a rare occurrence. 

My car is twenty years young, perhaps half of the annual services were done by Mr T.
Once prior to my ownership and once in my ownership Mr T reported such a leak as being apparent and requiring a replacement pump.
The independent garage that also serviced it and myself for the last 8 years have been unable to find any evidence.
Perhaps it's part of pre emptive  maintenance by Mr T!

PS
My daily, a Ford that I bought new, has been serviced exclusively by the  Main Dealer., the  service is inclusive of Ford breakdown and recovery service. On 99K + now, a few years ago the cam belt was replaced as recommended by Ford.
I have read elsewhere that the water pump should be considered for replacement at such a time. The workshop Manager, the son of the MD of the garage considered the water pump to be very reliable and did not believe it warranted replacement. He also recommended an after market cam belt, at less cost than the Ford item. So far so good.
Perhaps just a different customer relationship.

PPS
The after market cam belt is a Gates belt.

Dev

Quote from: Joesson on January 10, 2023, 19:18@Dev said:
they (water pump) have a weep hole that will leak fluid once the seals on the bearings give way to let you know its time for replacement which is a rare occurrence. 

My car is twenty years young, perhaps half of the annual services were done by Mr T.
Once prior to my ownership and once in my ownership Mr T reported such a leak as being apparent and requiring a replacement pump.
The independent garage that also serviced it and myself for the last 8 years have been unable to find any evidence.
Perhaps it's part of pre emptive  maintenance by Mr T!

PS
My daily, a Ford that I bought new, has been serviced exclusively by the  Main Dealer., the  service is inclusive of Ford breakdown and recovery service. On 99K + now, a few years ago the cam belt was replaced as recommended by Ford.
I have read elsewhere that the water pump should be considered for replacement at such a time. The workshop Manager, the son of the MD of the garage considered the water pump to be very reliable and did not believe it warranted replacement. He also recommended an after market cam belt, at less cost than the Ford item. So far so good.
Perhaps just a different customer relationship.

I do not know the ethics of UK service and repair but over here it can be hard to find a trustworthy mechanic these days as the entire industry is spoiled.
Many believe their mechanic is trustworthy but how do they actually know. A lot of people that are not mechanically inclined or mechanically ignorant go through the life of their ownership over paying for parts and services and would never be the wiser recommending these people to their friends.
There is also incompetence of the mechanic where they will use a shotgun approach to everything and make the customer pay for his experimentation to solve a problem that a more experienced mechanic can solve at a reasonable cost. What is worse if they rummage though the car breaking plastic clips and other things that lead to future repairs.
 
This is why I do my own work but even if I can't I will at least try to confirm the diagnosis.
It's not always about saving money, there is a self reliance and preservation  factor if anything. Because of the internet we have that information at our disposal but that can be a hazard also.

Regarding belts the industry has done something very unique around 2006 to make them last longer and use less tension so they free up some energy savings. They added what is known as an overrunning alternator decoupler pulley that takes the deceleration shock out of the belt and drive system and in return increase MPG as well as service life of belt, tensioner and other components.   
 They made one for the 1ZZ application. I fitted the pulley to my 2ZZ engine and it makes a bit of a positive difference that can be felt.




Joesson

@Dev said:
Regarding belts the industry has done something very unique around 2006 to make them last longer and use less tension so they free up some energy savings. They added what is known as an overrunning alternator decoupler pulley that takes the deceleration shock out of the belt and drive system and in return increase MPG as well as service life of belt, tensioner and other components.   
 They made one for the 1ZZ application. I fitted the pulley to my 2ZZ engine and it makes a bit of a positive difference that can be felt.


Iirc that is something that @Carolyn and @Petrus fitted to their cars.

Petrus

Quote from: Joesson on January 10, 2023, 22:00Iirc that is something that @Carolyn and @Petrus fitted to their cars.

No, I have not fitted that freewheel pully. I understand what it does as well as what the theoretical benefits are.  The   problem with a dynamo is the weight of the rotor. It puts a reverse force on the belt when the engine decellerates revs.
By fitting a freewheel i  the pully, that becomes one way, thus eliminating the reverse force.
The snag is that the pully is heavier which increases the force when accellerating. It is also rotating mass ánd an extra complicatii¡on.
I opted for a larger diameter pully in aluminium because I don´t need hálf the output of the alternator. The result is a líghter pully and a lower revving rotor which in effect makes it lighter too in rotating mass ergo lighter on the belt in bóth directions. Ah and easier on rotor itself too.

Dev

It is not what Petrus fitted which is different which is an under drive lightened pulley.  The overrunning pulley works like a bicycle where the wheel is decoupled from the sprocket and can spin freely on bearings. This takes the shock out of the system and when getting back on the gas the pulley is up to speed. Along with the pulley Toyota revised the tensioner to be weaker so there is less strain on the belt for the advantage of less parasitic losses.
It did not feel like it added noticeable power however it spun down the engine faster when applying the clutch making the synchronizers match better giving the transmission positive upshifts at any speed.

Dev

It is true that the overrunning pulley is an extra complication. They need to be replaced every 80-100k miles because the bearings give out. It is a dumb idea that nets about 1 mpg. A belt replacement is a better and cheap option.
The only reason I still have it is not to extend the belt life or for better fuel savings. The shifting is improved with positive timed shifts that feels like a different transmission making driving more enjoyable.

Carolyn

I run the stock pulley which is also a harmonic damper. 
Perry Byrnes Memorial Award 2016, 2018.  Love this club. 
https://www.mr2roc.org/forum/index.php?topic=63866.0

Joesson

Well my misremembering brought forth much information that could be useful to someone seeking that little difference or satisfaction in knowing that there is some benefit in stock.

Carolyn

There's plenty of evidence that running with an undamped lightweight pulley can result in oil pump failure, especially on engines (like ours) that use a pump that sits on the front of the crankshaft.
Perry Byrnes Memorial Award 2016, 2018.  Love this club. 
https://www.mr2roc.org/forum/index.php?topic=63866.0

Dev

I agree with Carolyn on undamped lightweight crank pulley but this is for the alternator pulley.

 After further recollection I have to make an amendment. The overrun alternator pulley might not be a dumb idea, it is after all an OEM Toyota part that is now widely used across the industry.
 
Although it needs to be replaced every 80-100k miles it has the benefit of prolonging not only the belt but also the tensioner, idler pulleys and water pump from what causes them to fail which is torsional vibrations on the bearings. This could extend their life greatly reducing ownership costs with the only downside being the alternator pulley replacement.  Edit: According to the manufacture it can extend vehicle component life by 2X.
 It does this by using a torsional spring in its design which absorbs  torsional vibrations and stress effects that also help dampen harmonic vibrations at higher speeds. This could actually benefit the engine as a whole. 

 

 

Petrus

#19
Quote from: Dev on January 11, 2023, 15:03After further recollection I have to make an amendment. The overrun alternator pulley might not be a dumb idea, it is after all an OEM Toyota part that is now widely used across the industry.
 

As I wrote, I totally get it and with mordern vehicles ´needing´ ever more potent alternators thus heavier rotors, it becomes more sensible.

On the ZZW30 however it is perhaps a bit overkill with the downsides outweighng (literally) the pros.

Oh and anything driven by the belt is in effect a harmonic damper albeit out of any control and working on/with/against the OEM harmonic damper....

Petrus

btw though there is no doubt whatsover that the OEM harmonic damper crankshaft pully works, the ponderings about the freewheel alternator pully concerning the load on the belt put this in a spotlight. Any change in forces on the belt is a change in the forces on the outer rim of the crankshaft pully.
Now, the high frequency vibrations on the crankshaft are basically in their own universe but the damping is a result of the weighty outer rim doing a different thing with a rubber strip between the two. Changing the ´weight´ of the outer rim changed the dynamics of the danmping. I mean, if the freewheel in the alternator pully makes life of the belt easier the effect on the pully harmonics múst be more than negligeable no?!

Travelling a bit further on this road, fitting a lighter flywheel, lighter underdrive alternator pully, fitting/deletng the AC pump, will all change the dynamics of the harmonia  :))
The moral of it being that when leaving all stock the story is clear: OEM is best. Any modifications change the dynamics and I personally have no doubt whatsover that while the mod. may have a benificial effect one desires, on the whole it will be a compromise with the OEM balance. Basically pick your venom when you go off the OEM path.

Dev

Quote from: Petrus on January 12, 2023, 09:03btw though there is no doubt whatsover that the OEM harmonic damper crankshaft pully works, the ponderings about the freewheel alternator pully concerning the load on the belt put this in a spotlight. Any change in forces on the belt is a change in the forces on the outer rim of the crankshaft pully.
Now, the high frequency vibrations on the crankshaft are basically in their own universe but the damping is a result of the weighty outer rim doing a different thing with a rubber strip between the two. Changing the ´weight´ of the outer rim changed the dynamics of the danmping. I mean, if the freewheel in the alternator pully makes life of the belt easier the effect on the pully harmonics múst be more than negligeable no?!

Travelling a bit further on this road, fitting a lighter flywheel, lighter underdrive alternator pully, fitting/deletng the AC pump, will all change the dynamics of the harmonia  :))
The moral of it being that when leaving all stock the story is clear: OEM is best. Any modifications change the dynamics and I personally have no doubt whatsover that while the mod. may have a benificial effect one desires, on the whole it will be a compromise with the OEM balance. Basically pick your venom when you go off the OEM path.

Maybe but there are forces that can be further reduce like NVH extending adding to the benefit of the OEM compromise just as much as adding mods that exacerbate it as you mentioned. The torsional spring in the OAD pulley  reduces these forces where they can be the most damaging like during vehicle shutdown and can absorb forces even when during high speed operation.  This part has been listed as being backwards compatible for both the 1ZZ and 2ZZ by various manufactures of the OAD so I do not believe there are any negative effects.
 Like I mentioned before it does not have a positive or negative performance benefit in acceleration that I can appreciate over the OEM but what it does for positive shifting is obvious and worth it.