Turned 100,000 miles today & still with pre-cats!

[1000 PR]

Car is just over 9 years old

Decided against replacing pre-cats 2 years ago on recommendation of Toyota specialist as car had done 80,000miles already and all the bolts looked as if they would disintegrate if I tried!
 
Using oil on an increasing basis but probably less than an Mazda RX-8 and I just check regularly and top-up every other weekend but cheaper than replacing engine!

Recent oil change wuth Mobil S and added 'Restore' as recommended by Quention Wilson but car still pinks when hot.

Cooling system has just started losing coolant somewhere so something else to top uo at the weekend!

A few other minor ailments (like myself) but a great car otherwise!

[WillsSayers]

Oh this has to be a wind up? One of the symptoms of engine death is an cumalitive use of oil, and now you're saying your 100k engine is fine - asides from the increase of oil usuage......?

[1000 PR]

Why a wind-up? Most of my cars use oil, some more than others and oil costs a lot less than an engine replacement!

Some of us run cars on a budget and that's possibly why we bought a relaible Toyota in the first place!

[1000 PR]

My post was to paint a more positive picture about pre-cat's rather than the usual doom and gloom!

When I said about increasing oil consumption I'm not talking about litres per day!

Yet!!!!!

[Anonymous]

Using oil on an increasing basis but probably less than an Mazda RX-8 and I just check regularly and top-up every other weekend but cheaper than replacing engine!

That is your problem right there, consumption has increased, obviously something has changed.

[1000 PR]

Not exactly - it's been using oil for the last 5 years at least!

Surely just the oval engine bores becoming more oval?

[Anonymous]

Not exactly

Surely just the oval engine bores becoming more oval?

Which is a change then, meaning that soon your main cat will be clogged with oil and probably pre cat debris and your engine will die.

The advice you were given was flawed im afraid.

[Anonymous]

Which lets oil past which melts the precats...


Congrats on your blinkers, they fit really well!  s:D s:D

[1000 PR]

It was probably too late to save the engine at 80,000 miles when I found out about the pre-cat issue!

Thanks for the doom and gloom to add to my day!

[Anonymous]

It was probably too late to save the engine at 80,000 miles when I found out about the pre-cat issue!

How can you be sure?

Thanks for the doom and gloom to add to my day!

Well your thread seemed to smugly say that you had 100,000 miles with no pre cat problems, when in reality..........

[roger]

Thanks for the doom and gloom to add to my day!

Yes, Nelix and Dan_M are quite good at that   s:wink: :wink: s:wink:

[mrzwei]

On the positive side, good to know that you can get to that milage on a 1ZZ. People forget that if an engine is using oil then what you need to do is top it up regularly, in the same way that you need to fill up with petrol   s:D s:D  . I had a Volvo 240 estate with 165k on the clock, did start to sound like a diesel though but hey.

[Anonymous]

Sorry Roger, im sure that engine is good for another 100,000 miles, Dan and i are just being silly.

[Anonymous]

Thanks for the doom and gloom to add to my day!

Yes, Nelix and Dan_M are quite good at that   s:wink: :wink: s:wink:

Because clearly Will didn't post in this thread either? Roger, if you're going to criticise people for stating the truth, you might want to at least keep some level of consistency. Or perhaps you would prefer a forum where we completely ignore the obvious?

I expected better from you.

[roger]

Thanks for the doom and gloom to add to my day!

Yes, Nelix and Dan_M are quite good at that   s:wink: :wink: s:wink:

Because clearly Will didn't post in this thread either? Roger, if you're going to criticise people for stating the truth, you might want to at least keep some level of consistency. Or perhaps you would prefer a forum where we completely ignore the obvious?

I expected better from you.

In my best Irish accent "Its the way you tell them"

[mrzwei]

For fucks sake you lot, there aren't many 100k cars that don't use oil. The solution is to check it regularly and top up  regularly. Eventually as with everything, it will expire. This ongoing battle is getting boring - grow up.

[Anonymous]

100,000 is a good result you should be pleased,any mileage now is a bonus.  s:bounce: :bounce: s:bounce:

[jonfy]

My post was to paint a more positive picture about pre-cat's rather than the usual doom and gloom!

When I said about increasing oil consumption I'm not talking about litres per day!

Yet!!!!!

I agree with the "elder" members of the club in that the pre-cats should have come out as it is well documented what happens to your engine/cat etc if they fail, HOWEVER i can understand with the Op's point of view.
Granted he was misinformed about the pre cats by Toyota but what's his car worth in real terms ? 100k mileage, 9 years old, best part of not a lot really !£2000 ish maybe.What's a replacement engine and cat going to cost, £1500 fitted,  therefore just keep topping up until it dies and sell it as a non runner for £800- £1000 and move on.
Hindsight is great, he choose to rely on someone else's "expertise" and took his chances,rightly or wrongly( maybe his engine would be in fine fettle now if he removed the pre cats,or at 100k past its best anyway) I don't think he was being smug or gloating, just stating his personal experiences.

Is it me or is it gettinga bit  caustic on here if you are not a regular poster  s:oops: :oops: s:oops:

[custardavenger]

I don't believe there is a precat problem, I believe its an oil control ring problem, after all that is the problem Toyota fixed, they haven't ever changed the design of the precats. If you get a pre 2003 engine to 100K you're doing well.

[FGrob]

I don't believe there is a precat problem, I believe its an oil control ring problem, after all that is the problem Toyota fixed, they haven't ever changed the design of the precats. If you get a pre 2003 engine to 100K you're doing well.

I agree with you 100% on that Rob, why else would Toyota change the piston design in 2003.

Precats as a individual component do very little except to reduce your emission during cold start - good old yanks hey, so when they fail, it's either as a result of someone hitting them or taking a heavy knock or another component failing which in turn causes the precats to fall to pieces. Those people who decide to run and ignore this, run the risk of either total oil loss or bearing failure due to precat dust - you take your chance I say and good luck with your decision and if you do achieve over 100K good for you.

Another problem that people are facing is the previous owner history, cars are becoming more affordable but if the car as not been treated right - buyer beware.

Rob.

[mrzwei]

Is it me or is it gettinga bit  caustic on here if you are not a regular poster  s:oops: :oops: s:oops:

  s:lol: :lol: s:lol:   On this forum? Nah!

[ChrisGB]

Car is just over 9 years old

Decided against replacing pre-cats 2 years ago on recommendation of Toyota specialist as car had done 80,000miles already and all the bolts looked as if they would disintegrate if I tried!

That puts your car in the high risk bracket for engine failure.
 

Using oil on an increasing basis but probably less than an Mazda RX-8 and I just check regularly and top-up every other weekend but cheaper than replacing engine!

From what I can work out, the pre cats are a symptom of the oval bore problem. Oil consumption goes up and gets into the combustion process and into the exhaust system where it causes the pre cats to run very hot leading to them crumbling. The valve timing controlled EGR function then draws sharp bits of ceramic, coated in rock hard metal, into the cylinder bores which then results in very accelerated bore wear, and before you know it the engine is using enough oil to cause either oil starvation or problems running. If you take the pre cats out before they crumble, the oil loss will get worse over time, but your engine is significantly less likely to suffer catastrophic failure. Topping up the oil is cheaper than replacing the engine, so is removing the precats early.

Recent oil change wuth Mobil S and added 'Restore' as recommended by Quention Wilson but car still pinks when hot.

Cooling system has just started losing coolant somewhere so something else to top uo at the weekend!

The car is pinking when hot. This could be a result of low coolant level leading to the head overheating, or more likely given the oil consumption, the presence of oil in the combustion chambers causing detonation. What happens is that as the piston rings start to fail, or the bores get scored, the combustion pressure gets past the rings and pressurises the crank case. This leads to excessive oil mist being breathed into the inlet side of the engine. Once this gets to the cylinders, it compression ignites and you get pinking. Alternatively, the oil causes carbon deposits to build up in the head and on the piston crowns, this glows and ignites the fuel before the spark fires. So it could be you have really bad oval bores (oil consumption in the 1L/ 1000 miles area) or scored bores, or at best, a bit of oil consumption and low coolant. I am hoping it is just low coolant level. Either way, pinking needs to be sorted as it puts huge mechanical and thermal stress on the engine. IMO this is a safety issue as pinking can lead to an engine going pop.

For anyone else considering leaving precats in on a pre facelift car, consider that bores going oval seems to be quite sustainable if the precats are removed. If the car suffers oval bores and the precats are in, then you run a high risk of rapid and catastrophic engine failure.

Keeping me fingers crossed for you.

Chris

[mrzwei]

That's a really well structured analysis.
The other perspective is that the engine has done well to get to 100k so all you need to do now is to watch the oil. Obviously eventually it will die, but excessive oil consumption alone won't write off the engine. Depends upon what you want from the car. If it's the daily commute then just watch the oil, if you want to race it or track it then  new engine now I guess. Check the plugs are right for the pinking issue and / or try upgrading the octane (won't get rid of the cause but may solve the problem).

[ChrisGB]

Trouble with pinking caused by oil is that the oil droplets ignite before the spark fires, so no amount of octane increase (or the cars built in knock compensation) will prevent it. On the other hand, if it is carboned up, running a good premium fuel like Shell V power, with its high grade detergents, may clean the head and crowns up a bit. For the sake a  few quid over two or three tankfuls it is worth a punt.

Chris

[uktotty]

I have 109k and never used any oil