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Hello,
I am 19 years old and am looking to purchase a 2009 Lexus Is250 Manuel from a 3rd party and heave been reading online about a carbon buildup issue and just wanted to know how serious of an issue it is and if I should even avoid the car as i am not too mechanically inclined to do many repairs. Also if you have any other advice or anything i should look out for before buying it i would appreciate it.
Thanks Alot
It has 87k miles and they want $10,500 for what it’s worth.
The bad news is that every 4GR-FSE will have carbon issues unless the owner/operator does something to address it. As well as every 3GR-FSE that you'd get to swap in. It's just the nature of the design; we (the royal "we") didn't know this would happen with direct gas injection at the time.
The good news is that letting it build up for a quarter million miles doesn't seem to damage any hard parts, even in the extreme case of carbon fouling holding a valve open, which I assume is why the engine was junked and I got the heads for so cheap. My experience with both 4GR and 3GR engines is that a decarbonization treatment is needed every 3 oil changes to keep the factory air paths flowing the factory-designed amount of air, thus producing all the power those little drinking straw ports can allow...though now that I think about it, I don't think I've ever gone 4 changes without, so that might even be too often.
The decarb process is pretty easy. Get the engine warm on your way to get a can of SeaFoam, pop the hood, then pull the hose off of the brake booster drum and cap it with your thumb. Then, slowly open your thumb and pour some seafoam into the hose going to the plastic intake manifold. The engine will go up and down in RPMs, if it stalls, no big deal, just reconnect the hose and start it again. If you leave the brake booster hose open too long you'll get a dash light telling you about the new vacuum leak...pull the negative battery cable, hold the starter to drain any capacitors in the system, reconnect the cable, start the engine to clear any such codes. When you have fed your engine the whole can, let the engine cool and drive the snot out of it sometime and somewhere that nobody'll call the fire department on you for laying huge clouds of white smoke that'll put a tear in even the most jaded of Subaru Bros' eye.
Then change your oil and filter and forget about it for another year or two.
I'd write a book telling you about all the other things to do to the car, but you don't even have it yet...
Hello,
I am 19 years old and am looking to purchase a 2009 Lexus Is250 Manuel from a 3rd party and heave been reading online about a carbon buildup issue and just wanted to know how serious of an issue it is and if I should even avoid the car as i am not too mechanically inclined to do many repairs. Also if you have any other advice or anything i should look out for before buying it i would appreciate it.
Thanks Alot It has 87k miles and they want $10,500 for what it’s worth.
I just bought 2008 IS250 with 155K miles for $8,500 last week shown in video below. I didn't think it was a good price since I bought 2006 GS300 with 106K miles 3 years ago, which was in better condition than the IS250. But due to used car inflation, used Lexus cars are probably 50+% higher than pre-pandemic 3 years ago. If I had a choice to buy 2009 IS250 with 87K miles, I would definitely pick your's.
As for the carbon build-up of your 4GR-FSE engine, my 2006 GS300 has similar 3GR-FSE engine, and just 9 months ago, I opened up the intake valve covers to manually clean the carbons, it wasn't difficult but it took a lot of work. At the timing of the carbon cleaning, GS300 just had almost 115K miles. The carbon build up wasn't super bad to a point where I was risking major failure, but I think it was bad enough to effect the performance, so I went ahead and cleaned it.
The bad news is that every 4GR-FSE will have carbon issues unless the owner/operator does something to address it. As well as every 3GR-FSE that you'd get to swap in. It's just the nature of the design; we (the royal "we") didn't know this would happen with direct gas injection at the time.
The good news is that letting it build up for a quarter million miles doesn't seem to damage any hard parts, even in the extreme case of carbon fouling holding a valve open, which I assume is why the engine was junked and I got the heads for so cheap. My experience with both 4GR and 3GR engines is that a decarbonization treatment is needed every 3 oil changes to keep the factory air paths flowing the factory-designed amount of air, thus producing all the power those little drinking straw ports can allow...though now that I think about it, I don't think I've ever gone 4 changes without, so that might even be too often.
The decarb process is pretty easy. Get the engine warm on your way to get a can of SeaFoam, pop the hood, then pull the hose off of the brake booster drum and cap it with your thumb. Then, slowly open your thumb and pour some seafoam into the hose going to the plastic intake manifold. The engine will go up and down in RPMs, if it stalls, no big deal, just reconnect the hose and start it again. If you leave the brake booster hose open too long you'll get a dash light telling you about the new vacuum leak...pull the negative battery cable, hold the starter to drain any capacitors in the system, reconnect the cable, start the engine to clear any such codes. When you have fed your engine the whole can, let the engine cool and drive the snot out of it sometime and somewhere that nobody'll call the fire department on you for laying huge clouds of white smoke that'll put a tear in even the most jaded of Subaru Bros' eye. Then change your oil and filter and forget about it for another year or two.
I'd write a book telling you about all the other things to do to the car, but you don't even have it yet...
I did the Seafoam cleaning of GS300 around 108K miles, and then opened up the intake valves to manually clean the intake valve carbon build up around 115K miles.
When I was cleaning the intake valves manually, I tried soaking with SeaFoam and with Chem-Dip and kept on checking for carbon to become soft,
but even after several hours of soaking, carbon was not very soft. In the end, I literally had to scrape and brush off the carbon, which took many hours.
I think SeaFoam and other spray methods can help to prevent fast carbon build up, if you start early, and perhaps do it regularly every 10K miles before the carbon get hard baked onto the intake valves.
I did the Seafoam cleaning of GS300 around 108K miles, and then opened up the intake valves to manually clean the intake valve carbon build up around 115K miles.
When I was cleaning the intake valves manually, I tried soaking with SeaFoam and with Chem-Dip and kept on checking for carbon to become soft,
but even after several hours of soaking, carbon was not very soft. In the end, I literally had to scrape and brush off the carbon, which took many hours.
I think SeaFoam and other spray methods can help to prevent fast carbon build up, if you start early, and perhaps do it regularly every 10K miles before the carbon get hard baked onto the intake valves.
On my initial seafoam. I used 3 cans back to back. It got all cylinders well except cylinders 5,6. Once I disassembled the intake manifolds. With just a paint stick light tap. The soot fell off. Probably a good hard red line would of blew it off. Though I wanted to evaluate the outcome. This was at 80k miles now I'm sitting at around 120k miles. Here on out I will use a can of seafoam spray at every 10k oil change. Using the port above the evap purge valve. I'll have to find an vacuum line cap. Then make a small hole to allow the straw to fit in.
Also I strongly recommend a oil catch can.
The can I'm running. Just swap the lines for fuel rated lines 3/8 inch. Your local Oriley's has them. I typically go for the Gates brand.
2 months of use:
Last edited by MikeFig82; Sep 27, 2022 at 12:47 PM.
So 3 Seafoam cans you are referring to is spraying through TB or actually soaking with intake manifolds removed?
I do think Seafoam spraying will help only if used regularly, like every 5 to 10K miles. I plan to do the same after seeing the amount of carbon build up, and how hard they get baked on to the intake valves.
Interesting idea on making a permanent hole to fit the Seafoam spray nozzle, especially if you can cap it off when not in use, and open the cap to spray. Can you upload a picture of specific location?
As for the oil catch can, where did you mount that for ease of access to empty the can?
So 3 Seafoam cans you are referring to is spraying through TB or actually soaking with intake manifolds removed?
I do think Seafoam spraying will help only if used regularly, like every 5 to 10K miles. I plan to do the same after seeing the amount of carbon build up, and how hard they get baked on to the intake valves.
Interesting idea on making a permanent hole to fit the Seafoam spray nozzle, especially if you can cap it off when not in use, and open the cap to spray. Can you upload a picture of specific location?
As for the oil catch can, where did you mount that for ease of access to empty the can?
One can was sprayed through the throttle body, the other two was using an industrial spray bottle. I ran a 2ft 3/8" hose from the purge vavle intake manifold port. Running the car idle at 2000 rpms. Constantly spraying the fluid trying not to stall the car.
As for the vacuum cap. I was talking about getting a cap from the autoparts store. Not a permanent solution. They sell them in a box of assorted sizes. Once finished I'll put the OEM cap back on the RHD brake booster port.
For catch can location see link below. I just had a coworker machine me an L bracket. Then on a vise I bent it 90 degrees.
Here's a wild idea, perhaps a bad impractical one...
The 250's have that cold start injector. If one could find modulate that injector while on the road and feed it with a small pump under the right conditions, the engine could do some self cleaning.
Best conditions might be while decelerating and/or very light loads.
Yeah, I was playing with that for a while with the intent of hijacking the ~50psi fuel supply there for a small nitrous nozzle primarily for carbon reduction but also for some poops'n hoots on onramps. Wife vetoed that idea because she's scared of the giggle gas...the SCV plate is a better place to spray and the distribution of direct port is way better than fogging one bank more than the other, anyway.
But the theory is sound. Should just need a 12v apply signal to the cold start injector to make it work.
Here's a wild idea, perhaps a bad impractical one...
The 250's have that cold start injector. If one could find modulate that injector while on the road and feed it with a small pump under the right conditions, the engine could do some self cleaning.
Best conditions might be while decelerating and/or very light loads.
That's actually a cool idea, but I think adding carbon cleaners to the gas tank is supposed to have the same effect, but obviously that has to be done on a regular basis.
From what I saw when I opened up the intake manifold, the carbon build up was very hard baked on there, and even after soaking with popular carbon removers,
it still took a lot of scraping to remove them.
Last night I finally was able to spray two bottles of the Sea Foam Spray. With the straw it is difficult to spray. The instructions say hold for 7 minutes until empty. I can't remember if my initial use of one was that difficult. I ran one can at the RHD booster port, and the other at the purge valve port. I prefer this method since it injects straight into the manifold. The booster port is like an L pathway. After finishing the job I changed the oil, and reset ECU while I was doing it. Make sure you do this in a well ventilated area the smoke will be tremendous. The Sheriff's department was doing their nightly patrol when I had a smoke show going. Thank goodness he just rolled by.
Took it out for a test drive,and seems to run still smooth as before. The only thing I noticed on the short run my KCLV maxed out rather quickly. The outside temps are getting lower now so maybe that's it.
The spray foam is a different formulation than the original can. I recommend using gloves as the scent is hard to remove. A very pungent smell to be exact.
That's actually a cool idea, but I think adding carbon cleaners to the gas tank is supposed to have the same effect, but obviously that has to be done on a regular basis.
From what I saw when I opened up the intake manifold, the carbon build up was very hard baked on there, and even after soaking with popular carbon removers,
it still took a lot of scraping to remove them.
Remember this has direct injection to the cylinders and No fuel is present in the intake... so, no. It is different and that's why fogging the intake helps!
My theory is the location and design of the cold start injector typically allows a quick start no matter what cylinder fires first, therefore that location can't be too bad in regards to its dispersion pattern.
But ya, some dry run testing with an injector driver, a 12V pump, and mimic / measure the volume sprayed and dial it in to something tolerable so as not to stall the engine and there could be a solution. The complication being, starting the ingine initially. A 3-way valve at the injector could be the solution. An electronic one being best to switch being fueling and cleaning. *****, maybe we design a kit and we all retire??? lol Disregard how many times we get sued for cars burning down! Haha!
In short the system could be as simple as an on off switch and a vacuum sensor or adding a 3-way valve as mentioned above. When vacuum is at max from deceleration, fog it. Just don't fog it to a point of stalling it.
With small single cylinder 4 strokes being fuel injected, swiping an injector driver shouldn't be hard to source or build one from scratch from the internet. IMO we don't need to use much of any data from the ECM, a simple clock trigger at a fixed rate could be sufficient for testing... The clock sets the duty cycle of the driver for injection of fluids.
I don't even think you need to make it that complicated. Unplug the injector and wire some speaker wire to feed 12v from a momentary switch in the cabin. Use it like Hollywood portrays nitrous, by just holding down the button.
There's a word for people who spray actual nitrous like that: pedestrians. At the very least a WOT switch is needed, if not a window switch, fuel pressure cut, and bottle temp/pressure relays as well.
But to just spray more gasoline in there? You'll really just be making a trailerpark version of the 2GR-FSE's fueling system. Go hog wild. But don't try to feed voltage back into the harness, just zap the injector open with a momentary switch.
I don't even think you need to make it that complicated. Unplug the injector and wire some speaker wire to feed 12v from a momentary switch in the cabin. Use it like Hollywood portrays nitrous, by just holding down the button.
There's a word for people who spray actual nitrous like that: pedestrians. At the very least a WOT switch is needed, if not a window switch, fuel pressure cut, and bottle temp/pressure relays as well.
But to just spray more gasoline in there? You'll really just be making a trailerpark version of the 2GR-FSE's fueling system. Go hog wild. But don't try to feed voltage back into the harness, just zap the injector open with a momentary switch.
Read again or for the first time??? Haha! The objective is it managages itself for say a tank of fuel and removes a little build up at time using Sea Foam say right before an oil change is due.
Because it's uncharted territory, ya you could DC 12 the injector (although that might KILL it), and control volume with pressure but then you loose the atomized spray effect which should be the objective of using that sprayer in the first place.
That's why I say you need a 3 way valve. 1 to start the car and 2 to fog it when decelerating via the cold start injector that also starts the car!
Lexus Is250 Carbon Build Up
