1zz-fe (1.8 Vvt-i 2003)

[igormus]

hi there

i have just read an article from enet that one guy in russia has been suffering from the subject problem.

he has not come to a dealers but tried to dismantle and investigate a real reazon of oil consumption.

he describes each step of the engine dismantling providing with relevant coloured photoes. i focused on description of cyl liner condition. it is wonderful that all cyl liners still have a honing (!!!) -- it means the liners are not worn down. the problem with another, as follows:

once removed all three piston rings from each piston he has disclosed that all drain holes (4 ps on each piston skirt) located inside thhe scrapper ring groove are clogged (!!!) with oil slag. and it is understood the oil could not be drained from liner into the sump resullting its burning in combustion chamber.

GUYs --- it is thhe main reason connected with piston cooling only. Should MrT predict an oil jet into the piston from skirt (for the cooling purposes) then this oil burning problem could not be available at all. the similar piston cooling is designed in scania truck engines. this guy has just cleaned all pistons with grooves, changed all rings on originall ones and assembled the engine.

the result is very good. i wait for the reply from this guy in order to hanng it in forum for guidance.

reverting/cheers/igor

PS: in case you are interrested to see the photoes then i am ready to provide you with.

[cmia]

yes please

picture :)

[IKR]

Very interesting. I did a quick search and found this on the MR2 owners club, also supporting the same diagnosis:

http://www.mr2roc.org/phpBB2/viewtopic.php?p=146762

Having used a fairly consistent 0.6L per 1000 miles since 45000 miles, my oil consumption suddenly doubled at 75000 miles. I guess that a second piston now has blocked drain holes. Given that the car was registered in March 01, I might just have been able to get myself a new engine block had I not gone independent for the last service.......

Ian

1.8vvti GS estate. Petrol / diesel hybrid, given how much oil it uses.

[dawesy]

as long as the independent used genuine parts and the service conformed to manufacturers standards you can still claim. contrary to popular belief servicing dosnt need to be done by a main dealer for warranty. as long as it is done to manufacturers standards and genuine parts are used thats all that matters

[Black Knight]

...........and you can prove it

[shroud]

So how much work do you think it is to actually clean out these areas and then just put the engine back together with fresh oil. This may be a good option for someone on a car out of warranty.

[cmia]

So how much work do you think it is to actually clean out these areas and then just put the engine back together with fresh oil. This may be a good option for someone on a car out of warranty.

alot of labour...

Once you starting taking things apart.. on engines..

some things would need to be replaced.

[igormus]

So how much work do you think it is to actually clean out these areas and then just put the engine back together with fresh oil. This may be a good option for someone on a car out of warranty.

hi mate

Actually it depends on how soon the driver wants to drive a car.

It can take at least 3-4 days in case all spares are available.

The main point is that cleaning precedure must be done again once the oil consumption will be increased.

There maybe another way (??????) and I can not state it definitely -- whether one can pour in some HD solvent into the combustion chamber to dissolve these oil slags. It is understood -- after it we need to flash an oil system + oil change (+ filter). That is a question. It can prevent dismantling of the engine .

What do you think? Any ideas? All photoes clearly confirm that each piston is normally overheated due to normal working, but it is not admissible and it is the direct result of initial design rough mistake. Normally this engine must be equipped with an oil cooler installed in front of water radiator cooler. It is understood the control system must govern the oil temp in sump by means some sensors and bypass flow valves.

ANy comments?

thanks

[igormus]

as long as the independent used genuine parts and the service conformed to manufacturers standards you can still claim. contrary to popular belief servicing dosnt need to be done by a main dealer for warranty. as long as it is done to manufacturers standards and genuine parts are used thats all that matters

hello

in case the independent has adopted decision to dismantle the engine -- it is a definite proof that the car is under no warranty.

that is the point.

cheers/igor

[IKR]

I was wondering that last night. I wonder if Redex, or even petrol, poured into a hot cylinder and left for a few hours might dissolve the crap?

This is really interesting stuff. I was under the impression that the problem was bore wear, and as such it probably wouldn't get worse with time. This new theory (which sounds a lot more credible, and is backed up by a couple of references) is a lot more plausible. It also supports my observation that fuel consumption isn't affected - I would have expectd bore wear to increase fuel consumption.

Any thoughts? Is it worth chasing my local dealers for a fix in the remaining 1 month before the car's 7th birthday? Any hints on the best way to do this?

The last service didn't use branded components, but I have oil consumption data going back 3 years, demonstrating an oil consumption of 0.6L/1000 miles. It's now doubled though - presumably the drain holes on a second cylinder have got blocked. The real worry is that this implies you could get as high as 2.4L/1000 miles if all four cylidners were affected!

Ian

[igormus]

I was wondering that last night. I wonder if Redex, or even petrol, poured into a hot cylinder and left for a few hours might dissolve the crap?

This is really interesting stuff. I was under the impression that the problem was bore wear, and as such it probably wouldn't get worse with time. This new theory (which sounds a lot more credible, and is backed up by a couple of references) is a lot more plausible. It also supports my observation that fuel consumption isn't affected - I would have expectd bore wear to increase fuel consumption.

Any thoughts? Is it worth chasing my local dealers for a fix in the remaining 1 month before the car's 7th birthday? Any hints on the best way to do this?

The last service didn't use branded components, but I have oil consumption data going back 3 years, demonstrating an oil consumption of 0.6L/1000 miles. It's now doubled though - presumably the drain holes on a second cylinder have got blocked. The real worry is that this implies you could get as high as 2.4L/1000 miles if all four cylidners were affected!

Ian

hello Ian

Ifi case you are still in doubts then I can send you a photoes as self explained.

thanks

[cmia]

I think the problem its self is with the "piston" design, as toyota has already clearly admited.

( i am sure i read that some where)

So the only real soloution would be to replace the piston with another type from the toyota family,

Does any one knw the bore of the piston

I dont think putting redex concentration will clean out any thing..

However... maybe using Diesel oil... instead of your normal engine oil.. could clean out the junk.

[igormus]

I think the problem its self is with the "piston" design, as toyota has already clearly admited.

( i am sure i read that some where)

So the only real soloution would be to replace the piston with another type from the toyota family,

Does any one knw the bore of the piston

I dont think putting redex concentration will clean out any thing..

However... maybe using Diesel oil... instead of your normal engine oil.. could clean out the junk.

hello

i disagree with you for the following reazon:

1) the crank shaft pins are normaly designed with calculation of their strength, and their OD is the result of the same calculations;

2) each piston has own weight that is also taken when calculated the pins. In case you will use another pistons with another respective weight this will affect on the crankshaft pins both main and connecting rod resulting its crak (!!!) at max loading of the engine;

3) The problem is only how to cool each piston and prevent oil sllag origination. This point can only be sorted be means of an oil cooling jet from four nozzles as tubes taken from an oil system. It is clear that one'd degrease an oil temp in sump -- the way is either install oil cooler or to make sump with ribbing to cool it by coming air.

what do you think?

cheers/igor