Project Lexus IS 250 - This one'll be 'interesting'...

[Mike_Mac]

It's been a long, long while (over a year!) but I've finally motivated myself to get back into this and document the work done... More to follow (in much quicker timelines!)

Hope you enjoy it:

 

[Mr Vlad]

Hi Mike. Just seen the video where you've unfortunately found the engine is goosed. What surprised me was the amount of carbon build up on the inlet valves. Am glad you're going to strip that engine just for fun But in doing so you'll be showing us is250 owners that carbon does indeed build up in our cars here in blighty. The subject of carbon build up has been chatted about to near death here. General concensus is that carbon build up isn't that much an issue because of the fuel we have here and the frequency of oil changes. 

That car of yours must have been neglected. For oil to be blacker than that of a diesel kind of proves it.

If you could post that engine strip in the gen 2 IS section under something like 'look at all this carbon ' then that'll reach every is250 owner on here. 

Looking forward to the next episode of your build. Just like the GS it'll be a real guddun 👍

[Mike_Mac]

1 hour ago, Mr Vlad said:

Hi Mike. Just seen the video where you've unfortunately found the engine is goosed. What surprised me was the amount of carbon build up on the inlet valves. Am glad you're going to strip that engine just for fun But in doing so you'll be showing us is250 owners that carbon does indeed build up in our cars here in blighty. The subject of carbon build up has been chatted about to near death here. General concensus is that carbon build up isn't that much an issue because of the fuel we have here and the frequency of oil changes. 

That car of yours must have been neglected. For oil to be blacker than that of a diesel kind of proves it.

If you could post that engine strip in the gen 2 IS section under something like 'look at all this carbon ' then that'll reach every is250 owner on here. 

Looking forward to the next episode of your build. Just like the GS it'll be a real guddun 👍

Unfortunately the engines already gone - but I do have a few of the valves as a memento and a fair few pictures, so will post them up

ETA - Now that i'm back at home (was out walking) - to say the UK IS doesn't have a carbon build-up problem because of the UK's better fuel is like saying you won't get drunk if you only drink low alcohol lager - it just takes a bit longer...

I can categorically say that the valves on my 183K engine were carboned up badly. More interestingly, the replacement engine, at 29K and with a good history, also had quite a lot of buildup already - nowhere near as bad, but I still had to clean it out before I put the manifold back on (next video). I have photos of the before and after and it's clear as day!

Unfortunately, because a lot of this project was shot at night in poor weather I didn't capture as much as I'd have liked, bu hopefully quality will improve when I get back to the GS and another project I just picked up last week... 😄

 

[Mike_Mac]

As Vlad has already said, the latest installment has dropped...

 

[Mr Vlad]

WOW now that's really not good news that there was a build up of carbon on a 29k engine. Looking forward to the next installment video of the new engine. 

[Mike_Mac]

As an example - here is a valve I took out of the shagged engine:

Here is the intake port:

Here is the new engine (before) - much cleaner runners, but still carbon on the valve itself):

And here's the result of a bit of manual cleaning (not perfect, but still - a big improvement):

[Mr Vlad]

Blimey that's kinda scarey the amount of build up even after just 29k miles. Thanks for posting. This has got to be seen by all is250 owners here. Can you put a link to this thread in the gen 2 IS section? Not in any sub section. 

[Mr Vlad]

Great latest video Mike. What a b mmer with that crank pully. New engine sounds sweet and idling just right.

[Mike_Mac]

On 1/29/2023 at 12:48 PM, Mr Vlad said:

Great latest video Mike. What a b mmer with that crank pully. New engine sounds sweet and idling just right.

Yeah - it was a pain, but luckily everything swapped over pretty easily. 😄

[Linas.P]

On 1/22/2023 at 5:19 PM, Mr Vlad said:

Blimey that's kinda scarey the amount of build up even after just 29k miles. Thanks for posting. This has got to be seen by all is250 owners here. Can you put a link to this thread in the gen 2 IS section? Not in any sub section. 

It should be put in perspective - carbon accumulation is natural in any engine (worse in DI) and in the picture of 29k engine it is not excessive at all, the bigger problem is that in DI it never cleans-up but just continues accumulating, whereas in Port injected engine it would stay about the same (accumulate a little bit one day, then get washed-off a little bit the other day).

I think it is good time to consider oil catch-can now!

[Mr Vlad]

Today I watched a YouTube video on why Not to fit a catch can. It's to do with the loss of vacuum in the system that over a shortish time dilutes the oil and wrecks the engine.

Another video showed they're very good for cars driven hard all the time like race cars. 

[Linas.P]

2 hours ago, Mr Vlad said:

Today I watched a YouTube video on why Not to fit a catch can. It's to do with the loss of vacuum in the system that over a shortish time dilutes the oil and wrecks the engine.

Another video showed they're very good for cars driven hard all the time like race cars. 

If installed correctly the catch-can should not cause vacuum leak... in fact if it does then car wouldn't run very well at all, as the leak would be on intake side. Cannot understand how catch-can could cause oil dilution? 

Most modern cars has Positive Crankcase Ventilation (PCV), so the crank case is not under vacuum, but rather under pressure. Sure the PCV valve is vacuum controlled (could be solenoid controlled as well), but fitting catch-can does not require touching the PCV valve... rather just fitting catch-can on the "breather" tube going back into intake. As catch-can is sealed system and ventilation is caused not by vacuum, but rather by pressure from crankcase it should have no effect on the engine - apart of removing oil vapour from getting into intake and clogging valves.

[Mr Vlad]

I may have got something wrong Linas with regard vacuum loss. It was more to do with pressure loss because of the copper looking gauze. I'll have to find that video and post it. 

However fitted an oil catch can on the is250 does I deed require the pipe going to it needs taking off. The OCC connects to the two now loose openings. Helluva fidly job I found when I took the PCV valve off to replace it with a new one which typically had a slight different thread so couldn't be used. Mine rattled as it should and actually looked quite clean which surprised me so I re fitted it.

[Mr Vlad]

found it. Some comments are great some rubbish and some knock the fella for talking trash etc. 

 

[Mike_Mac]

Latest video now out, and it's finally done! (or as done as it will be, anyway...).

It's been an interesting journey and will pave the way for a far more interesting project that i'm busy cooking up now. Until then, the next video will be a Review drive of the IS250, then catch-ups on what I've done with the GS430...

 

 

[Spacewagon52]

I take my hat off to you sir! Your dogged determination and patience has been rewarded.

 

[Mike_Mac]

1 hour ago, Spacewagon52 said:

I take my hat off to you sir! Your dogged determination and patience has been rewarded.

 

Thank you! Quite a few times the thought ‘just effing scrap it’ did cross my mind… 😉

[Mr Vlad]

Hi Mike. Good to see the is250 is now on the road. Great to see what our cars look like with the carpets out. Have fun in it being your daily driver 👍

[Mincey]

Bravo Sir - I'm going to take my hat off to you too. You have done a fantastic job there.

[Mike_Mac]

Now the car's done, a final drive and review, and that'll probably be the last video on this car (although another, much more ambitious project is on the way...).

 

[Mr Vlad]

Excellent video Mike. A good honest accurate review 👍

[Linas.P]

Great review... agree with most of what you said... especially about it being great balance overall. I think this is best all-rounder car I ever had, which is very difficult to replace. It doesn't do anything perfectly, but it does everything well... going for any other car you always have sacrifice something significant, but not on these. I guess hence I am on my 4th IS250 now.

Gearbox can be modified to be fully "manualised", but there is no real benefit of doing it in IS250 (many people do it to IS350 with similar a760e gearbox in US). I found that myself I mostly use S and manual shifting for engine breaking and it does it rather well, as long as you use it as a "limit" rather than expecting full sequential it does what it meant to do well. 

If I would be really looking for something to improve on this car - then it would be slightly more powerful engine (sadly we didn't get neither 300, nor 350 here) and folding rear seats for practicality. I can't really thing of anything else. 

ML is indeed great system, but even "standard" 13 speaker system was very good on these cars. Overall, infotainment was kind of outdated compared to contemporaries, but nowadays can be replaced by android unit for ~£200-400. 

[Mike_Mac]

Thanks for the comments guys, and yes, the main lack is more power (why did Lexus leave the IS350 outside the UK market!?).

However, the next project (not on this car) should sort that out… 😉

[Linas.P]

Just now, Mike_Mac said:

Thanks for the comments guys, and yes, the main lack is more power (why did Lexus leave the IS350 outside the UK market!?).

However, the next project (not on this car) should sort that out… 😉

Don't say you planning to put 3GR into IS250... I if so you will beat me to it 😄 

[Mike_Mac]

Just now, Linas.P said:

Don't say you planning to put 3GR into IS250... I if so you will beat me to it 😄 

Nope - neither of those two things… 😇