JHanLy

Quick Story, i purchased my 06 Lexus IS250 AWD last summer. Everything was running fine for the first month and then i got a check engine light. i checked the code and it said i had a cylinder misfire, i believe p0301. I read that the car could have the carbon buildup problem, so i i used Lucas upper cylinder lub, and i also seafoamed my car twice and then i decided to change my spark plugs, ignition coils, oil change to see if that would solve the problem. which is did not. The CEL would be on and off through the course 8-9 months, it did not affect the performance of the car so i did not try to pour more money into the vehicle trying to fix it. The start of summer rolls around and the CEL light vanished and never came back on again for 4 months. Until now when the temperature dipped for the start of fall and the CEL came back on again. Anyone know what the problem may be? seems like the CEL goes on and off based on how hot or cold it is outside.......

Gville350

iTrader: (10)

P0301 is a Cylinder 1 misfire, from what I read online. I'd start by moving the coil pack for that cylinder to another, and see if the CEL code follows over to that new cylinder.

Report back on your findings.

JHanLy

Yes is it a cylinder misfire. In the past week the CEL would go on and off and i would see what what code i would get and everytime it should shoot me a different code. Sometimes P0304, sometimes P0305, P0301, or sometimes all 2 or 3 of them. I lent my car to my buddy for the past 2 days and he told me all of a sudden there was a drastic loss of power to the car and the CEL would blink, which i read the car is in limp mode. Anyways he returned the car to me and i tried diagnosing the problem and it threw out a P0304 code. It was late in the day so i decided to park my car in my garage and try and fix it the next morning. This morning i went to start up the car and the car ran completely fine, it didnt run in Limp mode and it didnt have a CEL.....

Im very confused to whats going on, i do plan on getting my car walnut blasted just cause there probably is alot of carbon buildup that needs removal but i keep going back to the fact that my car start and runs fine with no issues when its summer or its parked in my garage. But runs badly in the cooler months or when its parked outside.......

Gville350

iTrader: (10)

Yeah, sounds like the dreaded IS250 carbon build-up issue. I've read threads of other member commenting on having the very same symptoms, and after parking it overnight, the CELs magically went away. But sadly, they will return.

Report back after your cleaning!

lexpilot

Just curious guys, what is an average cost for someone to walnut shell blast intake valves?
i spent $60 at harbor freight for the stuff to do it over a weekend.
I know Gville350 saw my thread about it. Maybe I should start doing it for others.
Lex

JHanLy

I actually plan on doing it myself aswell. Not many shops around my area do it, but the ones that do i was quoted. $990CND at one shop and $780CND at the other taxes in so ill gonna try and save the $700-$900 and do it myself.

edit* i just realised i posted in your other thread aswell

Gville350

iTrader: (10)

You should! You definitely have a handle on the engine mechanics and how to manage the process with what you've got. All owners of Direct Injection-only vehicles would be to whom I'd market the service.

JHanLy

So i finally got around to Walnut blasting my intake valves. The whole job took me alil over 6 1/2 hours to do. I would of gotten it done quicker but the blaster gun i was using kept on getting clogged. Anyways i used the combination of the walnut blasting and then spraying and letting the intake valves soak in carb cleaner.





unfournately i got tired of trying to find the perfect angle to get a good pic of the carbon buildup but it looked pretty bad. Anyways im very happy with the way it turned out. I put everything back together and took a couple tries to start it. Then it fired up, sounded good and everything then i went to take my car for a spin and as soon as i get over 40mph the CEL comes on and it started flashing. My heart just sinks, its the same problem again. I dont have time to troubleshoot the problem till a couple days later, and i find out that its the Cylinder 1 and 2 misfire. I changed my Ignition Coils last year and i decided to keep the old ones just in case. Anyways just in case happens and i take those 2 Ignition Coils out and put in the 2 old ones back in. Start it up and the car runs great, take it to redline, take it over 60mph and the car feels faster and smoother than ever. Couldnt be happier and hopefully i dont have any more problems. Gonna install an Oil Catch Can next weekend.

Gville350

iTrader: (10)

Curious if you had tried moving the coil packs around BEFORE finding the fix in order to help determine if it was indeed the coil pack that was bad.

Good work on that blasting! Looking good!

Bobaboy35

Curious about this as well. OP, if the coil pack is the issue, is there any warranty on them? Seems like bad quality for the coil pack to start having issues after only 1 year.

JHanLy

I actually did not move the coil packs around since the coils were less than a year old, i didnt think that was the problem. Especially since i was convinced i had a carbon buildup issue. Also over the time 1 of the codes that popped alot was P0304 which was alot harder to get to, so i got abit lazy there. Like i said before, the codes that popped up would constantly change so in my head, changing them around wouldnt have done much. Anyways bad news, i took my car to work for the first time since the repair (parked inside my garage) and it drove fine and smooth and at the end of the work day, when it was cold, i did get a flashing CEL again, idled abit sluggish. turned it off, erased the code and then car drove fine again. Going to see how tommorow goes to see if it does the same thing. I may switch out all the ignition coils that i bought for the old ones and see how that goes.

I am contacting the company where i bought theses coils off of, to see if there is a warranty or not.