JL Manual Transmission Values Down the Road

zrickety

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Carbon buildup affects every DI only motor. That said, there are a bajiliion F-150s with 3.5 DI ecoboosts running around with 150k+ miles and they are just fine. No they don't make as much power as when new, but you would be hard pressed to tell.

While a few people have experienced poor running engines from a variety of manufacturers due to carbon buildup, it's mostly forum hype. Enjoy your vehicle and don't stress over what "could" but probably won't cause issues in the future
I agree with you, however it seems that driving style affects the build up. If they are under load, as many trucks usually are it is not so bad. If you drive easy, lots of idle or trying to get good gas mileage, these are the engines that get the bad buildup. Not saying this will happen to every 2.0 Jeep but it will depend on the driver. The gas detergents never touch the valves or intake ports unless there is a secondary injector.
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emptyminded42

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I will start off that I don't know much about the FCA 2.0L Direct Injection Turbo and carbon build up. The internet has jumped on the BMW getting clogged up with carbon deposits on the intake valves and has applied it to every direction motor.

I have own a few Subarus, the 2.0 DI Turbo used in the Forester and WRX are not seeming having major issues with carbon build up. To the average driver with 100k miles, they don't seem to have drivability issues or setting engine. The carbon build up will show up on a dyno.
My wife's Forester 2.0XT has 65k miles and no symptoms of carbon buildup negatively impacting fuel economy, power, or driveability. It's fine. I think carbon buildup on DI is overblown or Subaru has done enough engineering to avoid it. Mazda put in a lot of effort to prevent it on their motors but my Mazda3 only has 35k on it so too early to tell.
 
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Goosed

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My wife's Forester 2.0XT has 65k miles and no symptoms of carbon buildup negatively impacting fuel economy, power, or driveability. It's fine. I think carbon buildup on DI is overblown or Subaru has done enough engineering to avoid it. Mazda put in a lot of effort to prevent it on their motors but my Mazda3 only has 35k on it so too early to tell.
I saw a scope camera down a cylinder on a 2.0 WRX with 29k miles and the carbon buildup on the cylinder wall was nasty.

It’s like cholesterol. It’s there, it’s hanging out, and without notice it will slow you down and eventually get you.

Also had a buddy get his 7 series walnut blasted. Night and day difference. Was pricy but he said he didn’t realize how much performance he lost until after it was done. And his tailpipe stopped farting blue smoke every time he stomped on it.
 

emptyminded42

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I saw a scope camera down a cylinder on a 2.0 WRX with 29k miles and the carbon buildup on the cylinder wall was nasty.

It’s like cholesterol. It’s there, it’s hanging out, and without notice it will slow you down and eventually get you.

Also had a buddy get his 7 series walnut blasted. Night and day difference. Was pricy but he said he didn’t realize how much performance he lost until after it was done. And his tailpipe stopped farting blue smoke every time he stomped on it.
I hear this stuff all the time yet if it's not causing driveability, fuel economy, or performance issues why worry about it? It will probably not be a problem during our ownership and I'm definitely not paying the dealer to walnut blast it (our experienced service adviser never heard about it) and I'm not taking it to another shop based on rumors.

My Mazdaspeed6 had heavy carbon buildup around 60k
Completely, totally, entirely different engine. Not even the same generation.
 

zrickety

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A service advisor that never heard of walnut blasting is not that experienced, IMO. Some engines are better than others, for sure. But the fact is the top end of DI engines never get the gas additives, so they get build up. Will you notice a gradual drop in performance? Probably not. Is there a gradual drop in performance, absolutely.
 

JL Fan

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I think in the very long term - 8-10+ years down the road - they could hold a premium over the autos, but with fewer manual enthusiasts they may take more effort to sell.
BINGO. I think there will be manual enthusiasts…but that may be b/c I am one.
 
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