Isf coolant leak.

[Tee643]

Hi I had my isf moted  yesterday and theirs coolant underneath.I haven't had the car that long.It has 70k miles .It's a facelift model.

Any help is appreciated. Thanks

[steve2006]

Hello Tee and welcome to the LOC.

I’ve only driven an ISF once so that’s about my expertise limit but I’ve heard “Valley plate” mentioned a few times by owners.

Apparently the sealing around it fails resulting in a coolant leak 

which emerges in the place your pictures were taken.

The ISF guys will help you further I’m sure.

[steve2006]

More recently discussed than I thought just a couple of posts down the list.

 

[4969_LXS]

Unfortunately that's most likely the valley plate leaking. Tell tale sign is the coolant leaking down onto the gearbox bell housing and undertrays

[Tee643]

Thanks guys.any specialists in the Leeds or Manchester area.

I did check the engine bay doesn't seem to be any leaks.

Thanks again

 

[Tee643]

10 hours ago, steve2006 said:

Hello Tee and welcome to the LOC.

I’ve only driven an ISF once so that’s about my expertise limit but I’ve heard “Valley plate” mentioned a few times by owners.

Apparently the sealing around it fails resulting in a coolant leak 

which emerges in the place your pictures were taken.

The ISF guys will help you further I’m sure.

Thanks Steve

[Tee643]

8 hours ago, 4969_LXS said:

Unfortunately that's most likely the valley plate leaking. Tell tale sign is the coolant leaking down onto the gearbox bell housing and undertrays

Thanks

[4969_LXS]

14 hours ago, Tee643 said:

Thanks guys.any specialists in the Leeds or Manchester area.

I did check the engine bay doesn't seem to be any leaks.

Thanks again

 

I couldn't say if there are specialists in that area, I don't have any knowledge of there. 

You'll never see it in the engine bay unless you have a boroscope to look underneath the intake manifold. You might see it at the back of the engine near the firewall.

If you follow the post @steve2006has tagged, that Lexus dealership might be a safe option as a member of the service team has experience doing it. Everything is very brittle from years of heat cycling, injector connectors/tabs can be broken as well as knock sensors, none of which are cheap. SRD down south are pretty good from reading around too.

From research this has the potential to occur on every 2UR block, which includes the LS. I'd ring around a few Lexus dealerships and see if they have any team members that have done the repair before as this will help a lot, make sure they use the updated sealant too where ever you get the work done. 

Have a good read around the web and on YouTube, it's doable on the drive if you're mechanically inclined and very careful. 

[steve2006]

I watched a YouTube video recently on this problem and the guy mentioned the problem was being caused by using the wrong type of coolant (Toyota pink instead of red) which reacts with the sealant resulting in the leak?

[Rob RCF]

6 hours ago, steve2006 said:

I watched a YouTube video recently on this problem and the guy mentioned the problem was being caused by using the wrong type of coolant (Toyota pink instead of red) which reacts with the sealant resulting in the leak?

If it's the same video I'm thinking of the information in it is extremely vague and he didn't provide anything even close to a reliable source for why the red should be used. It doesn't really make sense to use red, as pink is the modern type and what the manual calls for and what the dealership would use.

I preferred the Wrench Every Day video where they actually tore an ISF engine down and showed the valley plate leak in detail and discussed the cause of it and which sealant to use etc. Iirc the wrong sealant type was used during assembly, which got corrected at some point hence the later cars don't suffer from it as frequently.

[Tee643]

16 hours ago, Rob RCF said:

If it's the same video I'm thinking of the information in it is extremely vague and he didn't provide anything even close to a reliable source for why the red should be used. It doesn't really make sense to use red, as pink is the modern type and what the manual calls for and what the dealership would use.

I preferred the Wrench Every Day video where they actually tore an ISF engine down and showed the valley plate leak in detail and discussed the cause of it and which sealant to use etc. Iirc the wrong sealant type was used during assembly, which got corrected at some point hence the later cars don't suffer from it as frequently.

Rob,mine a 2011 car,I don't know when they changed the sealant.

[BillNick]

My first port of call would def be calling around Lexus dealers to find a tech that has done the repair.

I know it is 11 years old but sometimes you get cars with extended warranty in their 11th year - is yours?

Worth a try with the dealership as its a manufacturer fault known in the owners community though perhaps not official...

[Tee643]

32 minutes ago, BillNick said:

My first port of call would def be calling around Lexus dealers to find a tech that has done the repair.

I know it is 11 years old but sometimes you get cars with extended warranty in their 11th year - is yours?

Worth a try with the dealership as its a manufacturer fault known in the owners community though perhaps not official...

Mine doesn't have extended warranty.

I rang a dealer ,they wanted £105p/h.

[BillNick]

Right ok.

Though I can't help you find an independent specialist in your area (I am from Kent) the independent I would use down here if I had to charges £65ph + VAT to give you a ball park.

Provided nothing gets broken during the strip down, you only need the new sealant + fresh load of coolant for parts.

I'd be nervous doing any kinda cash deal as I would want a bill to prove the work.

Couldn't tell you how long it takes, pretty sure the youtube videos might give you a clue.

Sorry I am prob not helping your situation but do wish you luck matey

[Rob RCF]

3 hours ago, Tee643 said:

Rob,mine a 2011 car,I don't know when they changed the sealant.

I don't know when (or if) they changed the sealant either. Again the valley plate stuff seems to be based largely on speculation unless there was some official word from Lexus about it that I'm not aware of. It just seems that ISFs suffer from it the most.

It's possible that the change happened at some point for later ISFs, or it happened when the updated engine came along (RCF/GSF/LC500).

[4969_LXS]

I've read on American forums that 2014 ISF's have suffered the same leak as well as an RCF suffering the valley plate leak too. Rather than using a gasket or rubber seal setup, Toyota used sealant to secure the valley plate in the 2UR block, looks like this will be a common thing due to the design. The updated sealant has decreased the likelihood of this failure from occurring, hardly ever seen the later F cars report with this issue.

Time wise, I've read various quoted times to complete the job from 2.5hrs to 13hrs. Experience is a big bonus in lowering the time. Definitely worth a shot asking for a contribution from Lexus as it's a very well documented issue. Don't ask you don't get. But an independent with good techs shouldn't have a problem.

You have to unplug a lot of the wire harness clips on top of the engine to move it out of the way, remove the intake manifold with the port injectors in, remove a piece of foam, remove a piece of pipe that links both banks of direct injectors. Very very very carefully unclip the direct injector electrical connectors and pray they don't break. Remove the valley plate, clean the area and reseal, there's also 2 O-rings that connect a pipe to the valley plate that can get pinched. There's more to the process too.

In theory it's a low difficulty rating but a very tedious process. I'd of thought the RCF, GSF and LC500 would be slightly easier to do this on as they don't have the nest of wires on top of the intake manifold like we do.

[steve2006]

According to this video it took 30 minutes 😀

Pretty sure on the older FE  V8 engines there was a solid metal pipe which carried the coolant from front to rear mounted above the V which apart from possible O ring failures was pretty much problem free.

[Tee643]

2 hours ago, BillNick said:

Right ok.

Though I can't help you find an independent specialist in your area (I am from Kent) the independent I would use down here if I had to charges £65ph + VAT to give you a ball park.

Provided nothing gets broken during the strip down, you only need the new sealant + fresh load of coolant for parts.

I'd be nervous doing any kinda cash deal as I would want a bill to prove the work.

Couldn't tell you how long it takes, pretty sure the youtube videos might give you a clue.

Sorry I am prob not helping your situation but do wish you luck matey

Thanks

[Tee643]

22 minutes ago, 4969_LXS said:

I've read on American forums that 2014 ISF's have suffered the same leak as well as an RCF suffering the valley plate leak too. Rather than using a gasket or rubber seal setup, Toyota used sealant to secure the valley plate in the 2UR block, looks like this will be a common thing due to the design. The updated sealant has decreased the likelihood of this failure from occurring, hardly ever seen the later F cars report with this issue.

Time wise, I've read various quoted times to complete the job from 2.5hrs to 13hrs. Experience is a big bonus in lowering the time. Definitely worth a shot asking for a contribution from Lexus as it's a very well documented issue. Don't ask you don't get. But an independent with good techs shouldn't have a problem.

You have to unplug a lot of the wire harness clips on top of the engine to move it out of the way, remove the intake manifold with the port injectors in, remove a piece of foam, remove a piece of pipe that links both banks of direct injectors. Very very very carefully unclip the direct injector electrical connectors and pray they don't break. Remove the valley plate, clean the area and reseal, there's also 2 O-rings that connect a pipe to the valley plate that can get pinched. There's more to the process too.

In theory it's a low difficulty rating but a very tedious process. I'd of thought the RCF, GSF and LC500 would be slightly easier to do this on as they don't have the nest of wires on top of the intake manifold like we do.

Thanks

[Tee643]

1 minute ago, steve2006 said:

According to this video it took 30 minutes 😀

Pretty sure on the older FE  V8 engines there was a solid metal pipe which carried the coolant from front to rear mounted above the V which apart from possible O ring failures was pretty much problem free.

He takes beer for payment 😀

[steve2006]

2 hours ago, Tee643 said:

He takes beer for payment 😀

And apparently lives near Rochdale 😀

[steve2006]

Just looked up the earlier 1UZ-FE engine where a coolant pipe is fitted as circled between the block and intake.

Does this mean that using advanced technology it was replaced by a cover sealed with a tube of special sealant at $120.00 a pop?

[Tee643]

31 minutes ago, steve2006 said:

Just looked up the earlier 1UZ-FE engine where a coolant pipe is fitted as circled between the block and intake.

Does this mean that using advanced technology it was replaced by a cover sealed with a tube of special sealant at $120.00 a pop?

Must've  tried saving money.

[ubersonic]

On 8/21/2022 at 5:45 PM, Rob RCF said:

I preferred the Wrench Every Day video where they actually tore an ISF engine down and showed the valley plate leak in detail and discussed the cause of it and which sealant to use etc. Iirc the wrong sealant type was used during assembly, which got corrected at some point hence the later cars don't suffer from it as frequently.

It's worth noting that that was probably either just Tavarish's opinion or something he'd seen on Reddit, he didn't cite any evidence/source for it and he also mentioned the internet myth about the Toyota 7M head torque (despite this being debunked back in the 00s) as another example of one of their "factory mistakes".

 

  

6 hours ago, Tee643 said:

I rang a dealer ,they wanted £105p/h.

That's not terrible, I had my ISF in with Lexus for timing chains/tensioners replacement the other month and the labour ran me 1100 for about ten hours work, so similar per hour.

 

  

5 hours ago, Rob RCF said:

It just seems that ISFs suffer from it the most.

You hear about it more with the ISF than the GSF/RCF because those cars are much newer so less likely to have suffered from such an age/mileage related issue.  You also hear about it just as much if not more with the LS460, GS460, GX460, LX570, and Toyota Tundra it's just as only one of them was sold in this country you don't hear about it here.

Having said that I don't recall hearing about any LS460s suffering it this side of the pond? Which considering that this ISF would be the second or third? UK car to present the issue leads credence to the theory that the seal failure is so prevalent in the USA due to their climate (ours being closer to Japans, where it's not an issue).

[Rob RCF]

It might be worth keeping an eye on coolant condition. Engine coolant can become acidic over time and then eat away at things. Lexus says change coolant at 100k miles which means most ISFs might still be on the original coolant.

Maybe it's one to change every 60k miles or 6 years, along with the supposedly "lifetime" trans fluid.

I'm planning to grab some test strips to see what mine's like.