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I picked up a 2009 IS250 AWD in Jacksonville 3 weeks ago and drove it 1300 miles home to Wisconsin.
i knew about the intake carbon issue and hoped this one would be okay for a while.
I brought our borescope home from work and wormed it through the brake booster vacuum line nipple to check a valve or two. YIKES!... (never have set the clock on the scope)
Well looks like some work to do.
Off to Harbor Freight for the cheap $29 siphon blaster and $20 box of walnut shells.
I do have a pressure bead blaster but the nozzle on that one is huge.
Added an aluminum tube extension to the pistol to reach into the ports:
I used a piece of plastic sheet with a 2X3 inch hole to duct tape to each port so the shells and dust wouldn’t get everywhere. Even though I had an industrial shop vac sucking next to the blaster wand in each hole, it was messy. Wear safety glasses.
There is a piece between the intake manifold and the ports in the head. It has a butterfly over one of the valves for each cylinder. My guess is it opens to the second valve when you go wide open or really need it.
here’s a shot of before and after of that piece:
Here are a couple shots of the actual ports and valves before and after plus the engine opened up:
Took about 30 minutes per port to move plastic and blast. A couple valves needed some carb cleaner and small stiff brush to get it clean. The fire order is 123456 and a wrench on the crank and the plugs out, you can find TDC easy enough to be sure they are closed.
I put new iridium plugs in also since the Intake was off.
Here is my YouTube of the before and after, much more dramatic on the difference. All in all not a bad week end project.
Home Depot compressor water separator as an oil catch can is next so I won’t be doing this again!
Lex
Thats awesome. i was actually thinking of paying someone to do this, but its hard to find mechanics that do it and the ones that do charge near $1000 to do it. but this seems doable for your average mechanic. Is there a write up u followed on how to do this?
Thats awesome. i was actually thinking of paying someone to do this, but its hard to find mechanics that do it and the ones that do charge near $1000 to do it. but this seems doable for your average mechanic. Is there a write up u followed on how to do this?
I did watch a couple YouTube’s on the general idea but I didn’t see anything specific for IS250.
There is an intake carbon thread here on CL with lots of pages.
Also saw some “port adapters” to hook the vacuum to with a small hole for the blasting nozzle. Didn’t think they were worth the $30 though.
The intake manifold has some connectors and hoses under the back side along with a hidden bolt through a bracket just past the PCV valve.
Put the low budget oil catch can on today.
used the Home Depot Air compressor water separator to start. https://www.homedepot.com/p/Husky-3-...03AV/100040942
Changed out the drain with aircraft fittings and cap.
I was able to use the original hose from the PCV valve to the inlet and used some stiff vinyl to the intake manifold so I can see if any oil is going past.
my location fits good with the sight shield too.
The separator has fins to sling the incoming air/water to the outside and then it has to pass a baffle and finally a sintered bronze filter before exiting.
I'm not sure how well it will work but if it catches 50% of what normally goes into the manifold, I can go 125K or more before the next cleaning.
Here are a couple pics, I’ll update how it works at the next oil change.
OP, would you be so kind as to share some details on how this vehicle is used? Like is it city car doing lots of short stops daily or maybe like mine 50+ mi per day a mix of 50% freeway 50% city creeping in traffic. Also how often is the oil changed?
Thanks...
2013Fsport, I just bought the red car in Florida. It was a 2 owner with the second getting it repossessed after a year. i got it from a buyer/seller who got it from the bank. The car had 107K on it when I got home to Wisconsin. I also have a white 2007 IS350 that I drive, this AWD 250 is for my daughter who will drive 35 miles of hwy after getting out of Milwaukee for work each day.
I knew about the carbon issue but hoped I could let her go a while but after scoping the valves I decided to do it so I would know where I’m at with it.
I'll update the oil trap at the first oil change. My only fear is that the moisture created from combustion and blow by will freeze on the sintered brass filter and block the PCV and vacuum to the intake manifold. Gets real cold here sometimes. I did leave the line from the right valve cover that goes to the intake snorkel prior to the Throttle Body so if the trap does plug up, it shouldn’t blow any seals or valve cover gaskets cuz it’s still vented on the low vacuum side.
Update on the catch can after 4000 miles:
i emptied at 1500 miles and got half a cup of crap out.
most was thin and watery but would not freeze. The rest was oily slime that looked more like what I expected.
Went another 2500 and it was over half full.
it has become obvious that I cannot go the full 5K miles between oil changes without emptying half way.
Unfortunately I’m going to remove the catch can because this is my daughters car and she lives far enough away that I will not be able to keep up with it. I put the PCV hose back the way it was after removing the can.
It really makes me mad because Lexus should have seen this coming. Now I have clean valves and a way to keep them that way but it’s too much of a hassle. What happens from here is the rings will probably get stuck in the piston lands and blow by will increase as compression goes down.
My advice to anyone is not to buy a car with a GDI engine until they figure out how to prevent the deposits on the intake valves.
I’m thinking I will look into a way to just vent it overboard with a draw pipe under the car and plug off the vacuum port in the intake manifold. Either that or some sort of solenoid valve auto draining catch can.
If this was my daily driver, I’d leave it on and drain when needed because it really does work and I believe my intake valves stayed as clean as they were after walnut shell blasting.
I'd guess it's 65% water though. The more humid the climate the more moisture gets collected. The engine itself combusts the moisture, the catch can simply collects it.
I think OPs on to the right idea with a solenoid dump valve but there are auto dumps for water traps but I'd guess they'd need cleaned on a regular basis to remain functional.
I thought it was mostly water too but after a week in the deep freeze it didn’t even get slushy.
I’m guessing it’s fuel and additives although it doesn’t readily ignite.
My pal at Lexus says these engines originally came with under sized pistons and rings that caused more than normal blow by which in turn created the intake valve coking and ring groove carbon problem.
For a while Lexus would change out the pistons and do a valve job and that seemed to help but eventually the misfire code shows up and you have to clean them.
I see Ford has a kit to inject fuel into the ports to keep the intake valve cooler and cleaner on their GDI engines.
What a joke!
Glad I have an ‘07 IS350 also that runs awesome with 210K on the clock.
Pleased with walnut shells results
