Lexus IS250 4GR-FSE Engine Carbon Build-up (merged threads)
06-21-10, 04:13 AM
#196
Since the port injection system in the 350 allows fuel to shower the intake valves, a good injection cleaner can help with carbon build-up. Attached is a fairly new product that has shown to be very effective. This could also help clean the combustion chamber in the 250. I plan on a 20K mile schedule for my 350. I would think 10K for the 250 could help.
http://www.amsoil.com/storefront/api.aspx
Koz
http://www.amsoil.com/storefront/api.aspx
Koz
06-22-10, 06:28 AM
#197
i had mine cleaned for carbon build-up in mid may and it helped for a week or so and then the rough idle came back along with the engine feeling like it's going to stall at stops again occasionally. this is freaking ridiculous!
06-24-10, 08:12 AM
#200
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I also had the vibration return shortly after the top engine cleaning. Spoke with Lexus Customer Service Rep who apologized and said it is a "normal" characteristic and it is "within factory specifications" and they would not authorize anything further. I also asked to speak with a Supv who gave me the same line. The apology means nothing- a Lexus with 20K miles should not have these problems- too bad they don't know how to really fix it and can't admit it and take some action, i.e. extent the power train warranty at least for this issue. Acura did this on a problem they had with CL and TL transmissions and replaced mine on an 8 year old car.
06-24-10, 08:18 AM
#201
that's just crappy! i had the induction service done and the vibration came back after a few days along with the car almost stalling twice again so far. i'm still waiting to hear back from my dealer on whether or not they will also do the tsib on this. no word yet and it's been 2 weeks!
06-24-10, 08:20 AM
#202
That was the same response Lexus has been feeding us 98-00 GS400 owners. We have low idle issues and the they refuse to do anything about it. Of course this was "normal" according to them. Seems like whenever they can't fix anything, calling it 'normal' all of the sudden allows them to stop working on our cars.
06-24-10, 08:49 AM
#203
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Perhaps if anyone has the repeat issues and the dealer DOES take additional action to fix it they could post the info here. Apparently, Lexus no longer cares about maintaining high scores for Customer Service and reliability- never thought I would see that happen. My last Lexus, a 97 ES 300 was never in the shop overnight.
06-24-10, 11:15 AM
#204
i just heard back from corporate about my situation and they said that the dealerships claims the induction service that they performed is more thorough than the rough idle tsib's procedure. can anyone mechanical out there verify this?
06-25-10, 06:22 AM
#206
it's more likely the fact that 95% of all 250s are automatics, so with only 1 in 20 being manuals it's not unusual most complaints would be from automatics.
06-25-10, 06:35 AM
#207
The reason why 6MT owners never notice any issues is because the idle speed is probably regulated to be a little higher.
It's a V6... It's not a naturally balanced engine and the lower the RPMs the closer you get to a resonant frequency. I think the software needs to be tweaked for a higher idle RPM in drive (when lights and A/C are off). Even at idle, there is some drag on the engine from the transmission / torque converter. On 6MT cars, depressing the clutch or shifting into Netural is the same as neutral in the 6AT cars.... and the idle is perfectly smooth.
It's a V6... It's not a naturally balanced engine and the lower the RPMs the closer you get to a resonant frequency. I think the software needs to be tweaked for a higher idle RPM in drive (when lights and A/C are off). Even at idle, there is some drag on the engine from the transmission / torque converter. On 6MT cars, depressing the clutch or shifting into Netural is the same as neutral in the 6AT cars.... and the idle is perfectly smooth.
06-25-10, 06:53 AM
#208
06-25-10, 08:42 AM
#209
There's a diagram and short explanation at this top engine cleaner site:
http://www.barsleaks.net/Refs/TEC_ap...app_notes.html
I don't know if it helps clarify anything, though.
http://www.barsleaks.net/Refs/TEC_ap...app_notes.html
I don't know if it helps clarify anything, though.
Who has used this TEC product?
06-25-10, 09:43 AM
#210
Looking at post #86, assuming my car's VIN is after these production numbers (I think it is but I don't have the VIN here at work with me, its in my paperwork at home), does this mean it is unlikely to have the carbon build up issue?