My ISF broke down today, Major transmission fluid leak!!!

[Twellsie]

3 hours ago, Toothy said:

Also - If you're looking for any auto box repairs and don't want to use Lexus, I can recommend Transmission Technology not too far from us in Knowle.
https://goo.gl/maps/kk8ahkULbR81DJA27

Not had any Lexus repaired by him, but Ken really knows his stuff.

I have lost all confidence in Lexus to be honest, the car will be going to Competition Transmission Services

[MNMJ]

This all sounds very grim and a far too frequent problem.

Does anyone know if the RC-F is at risk too? I imagine it will be a few years before any of ours start to reach 100k miles, but it would be good to know in advance

[NothernDan]

What a nightmare.

My car is a 2009 approaching 90k miles so have contacted Lexus today to inquire about doing the preventative work and having the rad/transmission cooler replaced plus any likely ancillary parts. Had my ATF replaced earlier this year and all was clean and uncontaminated so I'm hopeful the problem had not yet started on mine. 

Awaiting the quote but I'll be sure to share it on here once I get it so those of us awaiting this time bomb have an idea of what it might cost to prevent it before it happens. 

Dan. 

[C.B]

Depending on the cost, the RR Racing alternative might be worth considering also, which has other benefits and is also a permanent fix.

[NothernDan]

21 minutes ago, C.B said:

Depending on the cost, the RR Racing alternative might be worth considering also, which has other benefits and is also a permanent fix.

Ask the man Twellsie, it also comes with downsides for those of us who are not "track only".... ie. all of us. 

[Jim Gan]

On 8/10/2020 at 11:54 PM, Irish ISF said:

I've noticed a strange sound from my transmission when I changed manually from second to third under hard acceleration. It's kind of a squishy/squelchy sound if that makes sense. Kind of like when you step on a wet sponge. Anyone else notice this or know if it's something to worry about?

Youre hearing the belt slip, new drive belt will fix this.

[Jim Gan]

On 8/10/2020 at 11:54 PM, Irish ISF said:

I've noticed a strange sound from my transmission when I changed manually from second to third under hard acceleration. It's kind of a squishy/squelchy sound if that makes sense. Kind of like when you step on a wet sponge. Anyone else notice this or know if it's something to worry about?

Youre hearing the belt slip, new drive belt will fix this.

[AnCarraig]

Twellsie very sorry to hear about ur car. Do u mind me asking how many miles are on it??? 

[Twellsie]

3 hours ago, AnCarraig said:

Twellsie very sorry to hear about ur car. Do u mind me asking how many miles are on it??? 

120k

[C.B]

14 hours ago, NothernDan said:

Ask the man Twellsie, it also comes with downsides for those of us who are not "track only".... ie. all of us. 

Any more info on this? This was likely to be my preffered option when our of warranty next year

[Twellsie]

46 minutes ago, C.B said:

Any more info on this? This was likely to be my preffered option when our of warranty next year

The standard set uses the engine temp to warm the ATF fluid up from cold and vice versa when hot.

By having a seperate cooler for the trans you will need to take particular care that you warm the box up, i dont know if you have ever noticed that it doesnt like shifting in manual mode from cold? this period will take even longer

[Texas]

It also won’t use ‘Top’ gear until it’s sufficiently warm also. By not using top gear this keeps the revs higher In an attempt to heat up the Fluids.

[65mike]

Hi all.

Sorry to hear of the problem with the F Rich have you had anymore info as regarding why it has happened or what has caused this is it age related or something else.

Is this going to affect all is owners even the 250 owners or is it only going to affect the F cars only.

If you can keep us updated it might be helpful to fellow owners best off luck with the car.😶

65mike

[ColinBarber]

On 8/13/2020 at 9:19 PM, MNMJ said:

This all sounds very grim and a far too frequent problem.

Does anyone know if the RC-F is at risk too? I imagine it will be a few years before any of ours start to reach 100k miles, but it would be good to know in advance

Yes, technically it could happen as it has a water cooled ATF cooler, the same as every Lexus that has been sold in the UK with an auto transmission. Whether the RC F is prone to this type of failure, as with the LS430 and now IS-F, remains to be be seen.

[ubersonic]

On 8/13/2020 at 3:18 PM, Toothy said:

Rich - Can you get Dan at lexus to drain the gearbox oil and tell you if it's been contaminated with coolant or not.
If it hasn't, there's more confidence that the gearbox will be OK. Perhaps will make your decisions easier.

Would it not be easier to look if the engine coolant has oil in it? The leak would be a two way street.

[steve2006]

15 hours ago, ColinBarber said:

Yes, technically it could happen as it has a water cooled ATF cooler, the same as every Lexus that has been sold in the UK with an auto transmission. Whether the RC F is prone to this type of failure, as with the LS430 and now IS-F, remains to be be seen.

As you mention Colin this method has been standard practice. This also includes the LS400 models from the beginning of production but I have heard no reports of the same failure on these even given some are now 30 odd years old with hundreds of thousands clocked up. Once again I suspect the investment and qualities that went into the LS400 failed to continue after 2000.

[Arqum]

So what would be the concensious in getting the rad replaced to stop this happening? My ISF is. 2009 with under 30k on the clock. 

[Texas]

I would at the 10 Year or 100,000 mile mark just so I could sleep at night knowing this emerging problem was ‘fixed’
Doesn’t bear thinking about if this problem happened in the near future ( there were no precursors before catastrophe failure) especially as you are now aware of its potential.

You may not have the ‘Miles’ to warrant it but at 11+ years old the components that fail are gonna be aged.

 

[ColinBarber]

7 hours ago, ubersonic said:

Would it not be easier to look if the engine coolant has oil in it? The leak would be a two way street.

If it fails like the LS430 then it happens quickly, if not immediately. Which way it goes would somewhat depend on which runs at a higher pressure.

[NothernDan]

4 hours ago, Arqum said:

So what would be the concensious in getting the rad replaced to stop this happening? My ISF is. 2009 with under 30k on the clock. 

Getting mine done ASAP as a precaution mate. Mine is 2009 and just over 85k on it. 

Had my ATF changed earlier this year and no signs of contamination but I'd rather be safe than sorry and for £500 - £600 it's a better priced option than the alternative. 

[Toothy]

So those who are getting this changed as a precaution, can you share more details. Is this something your local Lexus is doing?
Mine's an '11 plate with 45k, I think I'm OK for another year or so. But would rather get it changed than it fail.

[ubersonic]

This is an interesting issue if it's as apparently as common as it appears (obviously it's a very small sample size but then so was ISF sales lol).  The strange thing is this isn't an abnormal design Lexus are using, having the ATF cooler inside the engine radiator is basically the standard layout on every auto car made in the past 40 years, the only differences being some also have an external cooler too.

You would have to assume it's an age issue not a mileage issue or this would have exploded on US forums years ago, and the only way this contamination can occur is if the cooler inside the rad has corroded, that obviously shouldn't happen especially when using OEM coolant.  If I remember right the ISF uses a unique radiator (nothing else in the Toyota database appears to use that part number) which would go some to explain why other second gen IS owners don't seem to be reporting the same issue.

TBH this sounds a lot like a design/production problem with the OEM ISF radiator itself, but strange that you don't hear much about it on US/Aus forums, maybe the early UK cars got a bad batch of rads /shrug.

[Toothy]

Would definitely be interesting to see if it's only '08 cars. Are there any known to have failed on younger cars. Could put that "early batch" theory to test.

[Arqum]

3 hours ago, NothernDan said:

Getting mine done ASAP as a precaution mate. Mine is 2009 and just over 85k on it. 

Had my ATF changed earlier this year and no signs of contamination but I'd rather be safe than sorry and for £500 - £600 it's a better priced option than the alternative. 

Agreed! I ain't risking it! Just had the belt tensioner and belt changed under warranty as it was making an inconsistent rattle. 

[NothernDan]

For those who are interested, this is my quote for the preventative work. Assume your 15% gold member discount off the parts so about £50 off the total.