chris2888

Hey all have a 07 IS250 AWD getting high mileage. 269k miles. Bought the car about 3 years ago and with my job I put about 50k a year on the car.

Love it and not really had any issues except front and rear CV axle replacement.

I have a mechanic friend that says I should get a carbon clean on the engine by having him put some cleaner direct in the line and let it smoke and burn out all the carbon. He said especially on the IS which I have seen on here. All I do is run seafoam in the gas tank.

Is this a good idea on this car or any others? Never done this and afraid it could mess up some sensors. Will it hurt the car to not do it and let the carbon build.

I plan on keeping the car another 100k if it will hold up. Anything else I should look out for over the next couple years? Engine, Transmission?

This is my first Lexus and thus far been real impressed.

Thanks for the help.

jr4div2

Obviously, you must have read the myriad of threads about carbon build-up on the 2.5L engine. If that is not the case, I highly advise it and you'll understand in a second. I'll give you my brief analysis of your situation.

Adding sea foam to the tank is good. The issue with the carbon build-up has to do with the fact that our engines are direct injection right into the cylinder. That means the intake valves never see gas and the gas is what typically washes away the gunk that turns into carbon on the valves. This gunk comes from the PCV system recycing crank case gasses back into the intake along with fresh intake air. This is the nature of DI engines. The reason the sea foam is occasionally good is that it keeps these blow-by gasses and other gunk in the engine cleaner so the PCV gases stay cleaner and the gunk on the valves isn't quite as bad. I've been told adding a good engine cleaner like Techron to your gas occasionally is also good. The point is to keep those recycled gases as clean as possible.

Others believe a catch can helps inline with the PCV which acts as sort of a filter which filters out the hot gaseous oils and keeps them in the can which has to be emptied on occasion. I also believe this would help, but only time will tell.

I have also heard that short in-town trips contribute significantly to the problem because the engine temp does not reach its hottest level and therefore the valves do not get hot enough to burn off a lot of the gunk and therefore, carbon builds up quicker. In your case, putting 50k/year on your car, I would think this is hardly a case. In fact, in your case, I would be surprised if you had significant additional build-up based on your driving habits. However, it may have been there prior to your purchasing since your car had close to 120k on it when you bought it. Once the carbon has deposited, the only real way to get rid of it is some mechanical method. I've never hear of burning it off. However, I have heard of people rotating the engine and soaking the valves to soften the carbon and then allow it to be blown out of the engine.

Bottom line,ask your mechanic how successful his proposed method has been in the past and use your best judgement. You might also see if he can show you what he sees. Unless you're have misfires, rough/erratic idle and setting certain codes with a CEL,, you're probably fine and your driving habits should not contribute significantly

chris2888

Thank you for the great reply. I have read about the carbon and never once had any stall issues or the dredded VSC code come on and the engine die, so maybe the long driving trips do help burn out the carbon.

All my mechanic says he does is take the seafoam and suck some up directly from the engine into the intake. Not sure if it's the same way on a DI engine or not. Honestly, I don't know enough about how it's done but have heard of it before. Supposedly is smokes like crazy for a couple minutes but that is the carbon getting burned out at an accelerated rate.

Will find more about it. Good thing is no codes or idol issues ever.

Is there anything else I need to keep a look out for that are noted with being problematic with these cars at higher mileage? Engine and transmission seem strong. Rear end quiet etc.

Thanks for the reply and help.

MikeyK02

iTrader: (7)

Walnut blast that betty and keep her going. Seafoam will due some loose carbon...but not whats been caked on

chris2888

It's crazy but I have actually heard of people using walnuts in an engine I think. Or I have drunk too much lol

jr4div2

I don't think there's much more systemically problematic about these cars. The only other thing I can think of is the alternator and the CV joint boots cracking which you already know about. For the alternator, there really isn't much you can do. It will go eventually and probably take the battery with it or the fuse. I'm not sure it has been concluded if the battery starts going bad first which overloads the alternator or visa-versa. As for the boots on the CV joints (this is for others reading this thread) , keep and eye on them. I've heard they can be replaced if they crack, but if you catch them too late, they spit their grease all over the wheel well and by then, they're probably too far gone to replace and a new axle will be needed. If you need to replace one, I've heard your best bet is OEM re-manufactured which are considered good as new, but a quarter the price. There are others that have used aftermarket, but there's really no real evidence I've seen to say these are good as OEM.

Keep an eye on your oil. At your mileage, engine wear is inevitable and it'll eat some oil You should check it occasionally to see how yours is doing.

Door lock actuators seem to be more than just a random failure, but not rampant.

I know the 350 has a pretty much built in time bomb on the water pump. Not exactly sure on the 250. Best to pop the engine cover on occasion and look for pink liquid down around the water pump and in the under car cover. If you see pink (assuming it's Toyota coolant), the water pump is going to fail soon.

I assume your dash and door panels have been replaced for the sticky and cracking issue. If not, you should see if you can get that taken care of. You may have missed that window. But if you don't see any noticeable pits, cracks, scrapes or cracks, you're probably good.

Do you have NAV? If so, there are several problems that eventually happen to the screen. They can be remedied with aftermarket parts or parts off ebay if you're handy and patient.

Have you checked the VIN on lexusdrivers.com? That'll tell you any recalls that may be outstanding.

jr4div2

I wouldn't bother until I notice erratic idle or misfires or codes. It's expensive and invasive, but all I've read about getting it done are amazed at how the perfomance of the engine is completely recovered afterward.

MikeyK02

iTrader: (7)

Not sure if serious

MikeyK02

iTrader: (7)

It cost me 500 for that service. And another 350 to do the waterpump, belts, and spark plugs during tge same job

Sub $1000 to be set for another 50-60k is not too terrible

jr4div2

That's really not bad at all actually, but if he's not having any issues, he can wait and do it when he does have problems. That's all I'm saying. His driving habits will really limit additional build-up I believe so he could go another 50-60k before having the first problem with build-up.

cjatkinson

That is an impressive amount of driving you do! 50k a year. Hopefully not in traffic. I periodically use prolong engine oil additive and believe that too may extend the life of your engine.

IamLexus

Wow that's a lot of miles, makes me hope mine makes it that far! Currently at 140,000. The only thing I ever added in my car is RedLine Fuel System Cleaner.