ameer90

Hi,

I have lexus is250, it was running excellent without any problems, I stopped it for two days, when I start up the engine yesterday,I notice there is Engine hesitation, I used OBD II tool to scan the code and I found
p0300
p0301
p0306

which means issue in cylinder 1 & 6, the CEL was off but the code has come as pending in the scan tool.
I cleared the code and I drove the car for 2 Km.
today morning, I startup the engine, there is hesitation but less than yesterday. also there is no pending codes.


does anyone can help me
what the problem exactly is?
because it happens only when I stop the car.

MikeFig82

iTrader: (13)

How many miles on the car? Carbon build up?

ameer90

it's 151000 mile, I thought it's due to carbon build up, what is the best way to remove it?

also, yesterday I drove the car for 90KM and today morning when I start up the engine, it was perfectly without any hesitation. I thing this will help us detect the problem.

I'm sure the problem will come again

MikeFig82

iTrader: (13)

Read this thread. Then do the test mentioned.

https://www.clublexus.com/how-tos/a/...mize-it-367282

cfauvel

interesting stuff

Wouldn't the cold start injector 23260-31020 be washing the backs of the valves a bit, albeit not as well as the IS350's port injectors?

do you think the BG GDI service actually work? or NEEDS to be walnut shell blasted?
https://www.bgprod.com/services/gaso...air-induction/

MikeFig82

iTrader: (13)

The CS injector only mist a few seconds before start up. literally you would need the injectors to be squirting right behind the valves like the IS350 to be effective.

As for the BG not sure I have never used it. What I have done is use seafoam to clean the valves. Depending how gumed up the valves are it may take a few cans.

If using the port above the evap line on the intake manifold. By doing this I then removed the lower intake to verify the effectiveness. It seems to hit most of the valves good. It doesn't quite hit the valves on cylinder 6 well. It still had a soot build up on the valves compared to the other 5. The remaining soot stuck on valves I just vacuumed up. They were pretty much spotless after that. If you follow the instructions on the seafoam can to the T you shouldn't have problems. Though I think it's only for a 1/3 down the vac line. Using the whole can won't hurt. Be prepared for a smoke show. So don't do this in a residential area.

cfauvel

Surely when doing this , it throws several codes for: o2 too rich, engine misfire etc....right?

2013FSport

iTrader: (2)

Mike, did this clean up the valves behind the closed butterflies or did you open them somehow before doing this?

2013FSport

iTrader: (2)

I wouldn't be surprised. A good long run afterwards up through some hills should clear them..

That said, most errors take at least 3 full drive cycles to clear.

MikeFig82

iTrader: (13)

I can't say for sure as I already taken the lower out once. When I wanted to tighten the nut on the motor side of the flies. Since I had seen a thread on the matter for it coming loose. At that time I cleaned the lower intake with carb cleaner. The flies seem to stay open on shut down. Unless it's not right on my car. The times I've removed the lower they're slightly open. I only assume once on start up they are closed.

2013FSport

iTrader: (2)

Last little thing. Don't forget to change your oil after using chemicals or anything else to clean the top end.

firelikeiy

Walnut blasting is actually really easy to do. Be careful with those intake cleaners. I'm replacing my engine because I used a system made by Berryman. I have used 3m and ATP AT-100 several times in the past without issue. I gave the Berryman stuff a try because it looked like an awesome kit. The directions said to inject the chemical with the engine at idle, wait 30 minutes and then go for a 10 minute drive. When taking the car for the10 minute drive it hydrolocked the motor and broke a connecting rod. The 3m and ATP kits have in their directions to keep the engine at 2k rpm while injecting the chemical which is different from the Berryman that just says to let it idle. Anyway, it flooded the intake manifold. I ended up walnut blasting the intake valves on the replacement motor I picked up. I bought a 20lb media blaster from HF and made a makeshift media wand to get close to the valve. I used coarse walnut shells as the media. While blasting I also had a shop vac going with a crevice tool in the intake to vacuum up the media while blasting and covered the opening of the intake with an old rag so the media didn't get everywhere. It costs me around $120 for everything to do it. I wish I would have just media blasted the valves from the beginning every time I did a spark plug replacement. It's definitely the way to go.

https://www.harborfreight.com/20-lb-...ter-68994.html
https://www.harborfreight.com/25-lbs...dia-92150.html
I used the larger tubing from this air wand with the sprayer that comes with the media blaster: https://www.harborfreight.com/20-in-...gun-68261.html

cfauvel

I assume you had to remove the upper and lower plenum ...then did the intake ports where the valves were closed, the turned the crank until the next set valves were closed....right?

That royally sucks about the engine.That must have been pretty expensive.

my kid's car is new to us with 104K miles...when should we do this?
The BG service recommends every 15K miles....which is about yearly.

WHY OH WHY didn't Lexus use the same injection system as the 350??!!!

cfauvel

I found this tool, that seems to make the walnut blasting a little easier in that the dust and gunk is not thrown everywhere.

https://www.ebay.com/itm/202732775020


Saw a video where he used a similar tool on a Mini-cooper and the valves ended up like brand new.

Thoughts on a Oil Catch Can to educe the amount of sludge on the valves?

firelikeiy

Yes, both upper and lower intake plenums need to be removed. You'll need new gaskets for the lower plenum but the upper could possibly be reused. Tape off the other 5 ports and any open to atmosphere lines like the case vent to prevent rogue media from getting in them. If you pull any spark plugs then at a minimum put the coil pack back to prevent media from getting in the spark plug tube. turn the crankshaft clockwise when looking at it from the front until the valves are seated and blast away.

Yes, it is stupid expensive and a waste of a lot of time. I was quoted a minimum of $4,500 for a rebuild and the shop actually recommended I just buy a JDM motor and swap it out which is the direction I am going. The JDM motor was just over $1k but a lot of parts from the old engine need to be reused since the JDM motor doesn't have the starting fuel injector. I'm swapping the engine myself to save some $$ but I am also replacing a lot of parts like the water pump, starter, alternator, AC compressor, a bunch of gaskets etc etc while I am at it. One of my kids is about to get their license so this car will go to them. I ended up buying a GS350 to replace it with for myself with the better 2GR-FKE motor.

With your car being at 104k miles I would probably do it. All of the chemical cleaners I have used have helped somewhat but walnut blasting gets the valves absolutely clean. That adapter you found on ebay would also make the job a little easier and I think it is worth the $30. Spark plugs are suppose to be replaced every 65k miles so you might as well just go ahead an do that too and just walnut blast every time you change plugs.

I also have an oil catch can on my car but most of the oil seems to come from the case breather tube that is attached to the intake line. I get very little oil in the catch can.