Carbon Build Up Problem On Is250

[13IS250C]

I'm sorry. I'm sure this question has been posted a million times, but I have Googled and everything I find is on older models than mine. I was hoping that maybe Lexus had corrected the problem. If not, I have some questions.

If I use a good fuel additive, will that help. I prefer Lucas Fuel Treatment.

My service advisor said that they might clean my injectors at 15k miles. If it is an inherent issue with that engine, shouldn't it be at no cost to me?

At what mileage should I expect to start seeing signs of lost power or rough idling?

Any information you can give me would be a help. Thanks!

[tex2670]

Carbon buildup issue does not impact '13 MY.

[13IS250C]

Awesome! Thanks.

[LEX-SV]

What changes were made to the later versions of 2.5L V6 engine to minimize the carbon build up problem?

[13IS250C]

I would be interested in knowing that too Lex. I'm going to see if I can find anything on Google.

[reyoasian]

Nothing was done, it is the same engine and everything remains unchanged (including the carbon buildup).

There is nothing Lexus can do to fix it, it's the design of the engine. The 4GR-FSE isn't the only engine affect by this issue, it's a widely known problem for a lot of DI cars.

Nothing you can really do except, use high octane gas, use full synthetic engine oil (not the mobil 1 crap), get intake manifold cleaned every 50K miles, etc. and pray that you didn't get a lemon.

[tex2670]

Nothing was done, it is the same engine and everything remains unchanged (including the carbon buildup).

There is nothing Lexus can do to fix it, it's the design of the engine. The 4GR-FSE isn't the only engine affect by this issue, it's a widely known problem for a lot of DI cars.

Nothing you can really do except, use high octane gas, use full synthetic engine oil (not the mobil 1 crap), get intake manifold cleaned every 50K miles, etc. and pray that you didn't get a lemon.

Then why does the service program only apply to certain model years, instead of all model years? And why would companies keep putting out DI engines if they will end up having to take the engines apart later on?

[LEX-SV]

Yes, I'd like to see the evidence that nothing was done to later IS250's

And before somebody states something like "service program only applies to early years since they are the ones with higher accumulated mileage", that is not evidence that nothing was done.

And the major automakers (such as with Mazda Skyactiv DI gasoline engines) have made design changes to minimize this problem. So with latest version of DI engines being sold today the carbon issue is greatly reduced by design.

[rooket]

Can you cure the carbon buildup using Sea Foam? It looks like that is what is done on my current car. My dealer was going to charge me $480 and they sent me out with a rental, stating it would take 2 weeks (needing to purchase fuel rails which were out of stock locally). The car was done the next day. I imagine that means they just fed a bottle of Sea Foam into it and spent half an hour and turned off the check engine code and let me have the car back. Why would they need to replace fuel rails is beyond me, it doesn't seem like that is a fuel rail problem. I don't plan on going to use their service department any more :) But it is ok, my dad used to work at a different dealer for the same brand of car so i can easily go there instead.

[13IS250C]

Ok, I guess my car has the virus now. Not even 14k miles. Rough idling, gas mileage dropping drastically and black soot on my bumper around my passenger side tailpipe. Needless to say, I'M !Removed!!!!!!!!!!!

How can Lexus keep putting an engine in a car that they know has a defect like this? I'm going to have a good ole southern hissy fit if they try to charge me anything to fix it. When I mentioned it to my service writer before, he just said "don't believe everything you read on the internet". I guess he thinks I'm an idiot.

[LEX-SV]

Let's see if the smart SA knows if any changes were made to later model IS250 D.I. engines....

[reyoasian]

When I said nothing was done, I meant nothing was done to fix the problem. There were small changes to some piston rings for later-2010 (not the early 2010's built in 2009) and so on models, however that's not a fix, and it only delays the problem, not eliminating it (motor remains unchanged). There are less reported carbon buildup issues for later-2010 and so on models, however it's still early considering the low mileage they have compared to 2006-2009 models. As well, it's sometimes a hit or miss thing (like BMW with the N54 HPFP issue, which claimed to be fixed with N55 but was not), and even the 3rd gen IS250 are being affected. As well for later years (forgot when it began), Toyota began using different specification engine oil, which does affect it to some degree as oil volatility is a factor in sludge contribution.

DI engines are more gas efficient, and cheaper to produce. I'm not saying the problem is consistent amongst all DI engines on the market, but this is a typical problem for DI engines in general.The Mazda SkyActiv is much, much newer vs. IS250's 4GR-FSE, I'm sure there are other manufacturers have been able to "fix" the problem with new technology. The 2GR-FSE on the IS350 is also a DI engine however not affected as Toyota designed it with twin port DI (since the beginning of the 2IS), which was not done on the 4GR-FSE, hence no fix for the IS250. Even on the 3rd gen IS250, the two-stage injection system is not used. It's definitely cheaper for Lexus to disassemble/change engine components to the small percentage of whiney customers (by TSIB) than making changes to its complete engine design and production process (which is due to be changed soon anyways).

For the meantime things you can do to prevent:

* high octane gas

* full synthetic oil

* synthetic oil stabilizer

* intake manifold cleaning

* seafoam

* WOT

* TSIB to get piston rings and engine top blocks replaced

WOT/seafoam only helps to a small degree as deposits are on the outside surfaces of the valve, where gas never touches in a DI engine. VW release statistics that you have to put heavy load on the engine for a long time in order for the engine to be hot enough to burn off the sludge.

So I will say it again, nothing was done to fix the issue.

[reyoasian]

Can you cure the carbon buildup using Sea Foam? It looks like that is what is done on my current car. My dealer was going to charge me $480 and they sent me out with a rental, stating it would take 2 weeks (needing to purchase fuel rails which were out of stock locally). The car was done the next day. I imagine that means they just fed a bottle of Sea Foam into it and spent half an hour and turned off the check engine code and let me have the car back. Why would they need to replace fuel rails is beyond me, it doesn't seem like that is a fuel rail problem. I don't plan on going to use their service department any more :) But it is ok, my dad used to work at a different dealer for the same brand of car so i can easily go there instead.

For IS250 MY 2006 to early 2010, the warranty has been extended to 9 years for the carbon buildup problem...why are you paying.

[LEX-SV]

Ok some minor changes like revised piston rings.

Yes probably 2.5 V6 engine is nearing EOL for Lexus, (likely tb replaced by turbo DI 4), so redesign not justified.

[rooket]

I need to unsubscribe from this forum. This was enough for me, sheesh..so many problems with this car and I don't even own one. time for me to back away from this whole thing.

[tex2670]

I need to unsubscribe from this forum. This was enough for me, sheesh..so many problems with this car and I don't even own one. time for me to back away from this whole thing.

Well--enjoy whatever car you end up with.

[LEX-SV]

So many problems with this car?

I only see one topic and/or problem here w/C250, carbon build up problem.

[dcfish]

I need to unsubscribe from this forum. This was enough for me, sheesh..so many problems with this car and I don't even own one. time for me to back away from this whole thing.

Goodbye...

[13IS250C]

I still love my car and every girl at every Sonic has a fit over it. I don't know if there are any perfect cars out there. I had a whole lot of issues with my G37.

[LEX-SV]

So we are now saying minor changes (like different piston rings) were made.

Probably driving technique, oil type/quality, oil change frequency, and high detergent gasoline use makes some difference.

Note: Its not hard to find IS250's with over 200K miles that run fine.

[13IS250C]

I'll let y'all know what my service advisor says when I take it in. I have about 500 more miles till my 15k checkup. I'm sure he will give me that same "dumb ole girl" routine that I usually get. Arrrrrg.

[LEX-SV]

I read the new Lexus turbo 4 banger in the NX crossover will have both direct injection and port injection (like the IS350 V6), kind of interesting...

[reyoasian]

I'll

let y'all know what my service advisor says when I take it in. I have

about 500 more miles till my 15k checkup. I'm sure he will give me that

same "dumb ole girl" routine that I usually get. Arrrrrg.

you still taking your car to be serviced at the stealership? i stopped doing that after i got my first one free, haha.

I

need to unsubscribe from this forum. This was enough for me,

sheesh..so many problems with this car and I don't even own one. time

for me to back away from this whole thing.

Well--enjoy whatever car you end up with.

he can have fun with the german/american counterparts ;)

----------------

excited for the NX as well, Lexus finally going forced induction for efficiency, although I personally always prefer a good ol' N/A over any boosted engine....

on clublexus there's a few people who hit 250K miles already

I just hit 80K KM recently, and once I hit 100K KM (60K miles), I will do a big maintenance and get my throttle and intake manifold cleaned up

[13IS250C]

I'll take it there as long as it is under warrantee. I have a back window that is rattling like Hell. I realize a convertible will have noises, but this is so bad I have to ride with the window down some or it drives me crazy. I hope it just need some adjustment.

[LEX-SV]

I'm still having Lexus dealership (only one in particular) do the service on my Lexus IS, even though it's out of warranty.

Since I only put about 5K miles/year on the car, my annual maintenance costs are still very low for a premium car. I get excellent service at my dealership via one service writer (somebody that I have been using for over 5 years straight). No complaints.