Engine sputters
01-17-19, 10:36 PM
#1
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Engine sputters
Please share your thoughts. The first time I noticed the engine sputters and had service on my 2015 IS250 F Sport was in May 2017. I noticed a few times early in the morning as I came to a stop, the engine sputters or “hiccuped”. The rpm needle bounced below 500 then bounced up to 800 for approximately 2-3 seconds. When I say ‘few times’, it was once every few weeks and always early in the morning before the car was driven more than 1 mile. Car had 15k miles then and always had Shell premium gas. Never pumped gas from random gas stations and always from the same Shell gas station. Service advisor suggested then that they normally don’t see carbon buildup especially with low mileage. The car had codes so they clean the engine.
Fast forward to today and now at 27k miles, the engine sputters again. This time the car was driven approximately 12 miles and in the afternoon. This time the engine sputters for approximately 10 seconds with the rpm needle bouncing between 400 - 800 multiple times.
Service advisor said again there was codes and they completed a ‘top engine clean’. He suggested that carbon buildup is normal in all Lexus models as well as all cars. He says that they actually provide different levels of engine cleaning - one using fuel additive and another type of engine cleaning at 30k intervals for all Lexus models.
When I pointed out that I never experienced engine sputters in my previous (Honda) cars which had over 150k, nor my friend’s 2013 RX350 which now has over 65k he suggested that he could not speak about Honda’s but my friend’s RX had received engine cleaning at 30k and 60k. I know my friend’s RX service history and no engine cleaning was done! I pointed out that although the recommended oil change was at 10k by Lexus, we actually complete oil changes at 5k intervals - both on my IS and my friend’s RX.
I just find it hard to believe the service advisor’s explaination that carbon buildups are normal in all Lexus models and that I need to “plan on” getting $800 top engine clean every 30k.
Thoughts?
Fast forward to today and now at 27k miles, the engine sputters again. This time the car was driven approximately 12 miles and in the afternoon. This time the engine sputters for approximately 10 seconds with the rpm needle bouncing between 400 - 800 multiple times.
Service advisor said again there was codes and they completed a ‘top engine clean’. He suggested that carbon buildup is normal in all Lexus models as well as all cars. He says that they actually provide different levels of engine cleaning - one using fuel additive and another type of engine cleaning at 30k intervals for all Lexus models.
When I pointed out that I never experienced engine sputters in my previous (Honda) cars which had over 150k, nor my friend’s 2013 RX350 which now has over 65k he suggested that he could not speak about Honda’s but my friend’s RX had received engine cleaning at 30k and 60k. I know my friend’s RX service history and no engine cleaning was done! I pointed out that although the recommended oil change was at 10k by Lexus, we actually complete oil changes at 5k intervals - both on my IS and my friend’s RX.
I just find it hard to believe the service advisor’s explaination that carbon buildups are normal in all Lexus models and that I need to “plan on” getting $800 top engine clean every 30k.
Thoughts?
Last edited by bmwlexus09; 01-19-19 at 05:54 AM.
01-18-19, 08:24 AM
#2
Lexus Champion
Hmmm...interesting.
Not all Lexus engines are susceptible to carbon build up. Carbon build up occurs with direct injected engines.
The IS350 engine, and other direct injected engines by Lexus don't have this issue because they also use port fuel injection. The PFI rinses the carbon off the valves, so there is no build up issue. On the IS250, there is no PFI, so the carbon builds up.
The 2013 RX350 does not have carbon build up because it doesn't have direct injection - it ONLY has PFI.
There have been design changes in the IS250 engine since I think 2010 to help mitigate the issue. I do not agree that the 2.5l should need a cleaning very 30k miles.
Not all Lexus engines are susceptible to carbon build up. Carbon build up occurs with direct injected engines.
The IS350 engine, and other direct injected engines by Lexus don't have this issue because they also use port fuel injection. The PFI rinses the carbon off the valves, so there is no build up issue. On the IS250, there is no PFI, so the carbon builds up.
The 2013 RX350 does not have carbon build up because it doesn't have direct injection - it ONLY has PFI.
There have been design changes in the IS250 engine since I think 2010 to help mitigate the issue. I do not agree that the 2.5l should need a cleaning very 30k miles.
01-18-19, 08:46 AM
#3
On a particularly sensitive engine such as yours, if you do a lot of short trips, that could speed up the time in which you need to have carbon cleaning done. Assuming that's the problem. If I were you I'd be driving the car hot hard and aggressively. And long if possible, at least weekly. This will help mitigate buildup. But if you're just putting along gently every morning for a few miles, stuff will build up fast.
01-18-19, 11:30 AM
#4
Could still be a bad batch of gas. I always used premium 76 when I had an FRS, which also has both PFI and DI. Every once in a while it sputtered in the am. Is this a once and done, or consistently every time you drive?
01-18-19, 12:14 PM
#5
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What were the codes? I'm assuming engine misfire codes, but if it's on your invoice, please share.
01-19-19, 06:02 AM
#6
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Thread Starter
Thanks all for your inputs. E46CT, my daily commute is 15 miles one way. But still to have that much carbon buildup that quickly? JDR76, thanks for educating me about direct injection and PFI.
I’ll ask the service advisor for the engine codes to post. Might not be able to get them for a few days.
I’ll ask the service advisor for the engine codes to post. Might not be able to get them for a few days.
01-21-19, 08:16 AM
#7
15 miles doesn't sound too bad. Is the sputtering something you can replicate easily and repeatedly?
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01-21-19, 04:50 PM
#8
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Here’s the response I received from the service advisor:
There were no codes in the system for the carbon build up. When he removed both upper and lower intakes, he noticed the build up on the engine valves. At that point, we were able to perform the top engine clean under warranty.
E46CT, no it’s not easily replicated. It’s always random. Back in 2017, it only sputtered in the morning and it wasn’t every morning either. Randomly it would sputter. At first it felt like a hiccup or almost like the muffler back-fired; quick once and done. This time when the engine sputtered, it was kind of like a how a lawn mower engine sputters - on and off, not sure whether it was going to stay on or it was going to shut off.
I’m still not convinced it’s carbon buildup. For those engine gurus, is there anything that might suggest cylinder, piston, spark plugs, etc? I’m open to suggestions.
There were no codes in the system for the carbon build up. When he removed both upper and lower intakes, he noticed the build up on the engine valves. At that point, we were able to perform the top engine clean under warranty.
E46CT, no it’s not easily replicated. It’s always random. Back in 2017, it only sputtered in the morning and it wasn’t every morning either. Randomly it would sputter. At first it felt like a hiccup or almost like the muffler back-fired; quick once and done. This time when the engine sputtered, it was kind of like a how a lawn mower engine sputters - on and off, not sure whether it was going to stay on or it was going to shut off.
I’m still not convinced it’s carbon buildup. For those engine gurus, is there anything that might suggest cylinder, piston, spark plugs, etc? I’m open to suggestions.
01-22-19, 05:02 AM
#9
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Here’s the response I received from the service advisor:
There were no codes in the system for the carbon build up....
I’m still not convinced it’s carbon buildup. For those engine gurus, is there anything that might suggest cylinder, piston, spark plugs, etc? I’m open to suggestions.
There were no codes in the system for the carbon build up....
I’m still not convinced it’s carbon buildup. For those engine gurus, is there anything that might suggest cylinder, piston, spark plugs, etc? I’m open to suggestions.
If the advisor is saying there's no codes in the system for the carbon buildup, does that mean there were other codes then?
In reality there are no codes for carbon buildup. What you get are misfire codes, P0300, P0301,..., P0306.
Granted that on a 2IS if you got those codes that likely meant that it was carbon buildup...like 99 out of 100 times...and the check light would flash when it happened.
Although, there is a handful of other things that can cause a misfire. And with the 3IS Toyota had fixed the carbon buildup issue.
However, carbon will still build up, as it would in any normal engine, over time.
Based on the mileage you drive and the fuel you use, I can't see this being a buildup issue. I use the same fuel and have the same mileage (roughly), and I'm puttering along just fine.
And I probably do way more short trips...which isn't a good thing.
If the light is coming on when this happens, then get yourself a code reader and see the codes for yourself.
That way it will give you a starting point to addressing the issue.
Right now the possibilities are broad...could be a spark plug, coil, or injector. These motors are pretty bulletproof mechanically, so I doubt it's a valve or piston.
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