Direct Injection-Why I'm Happy the 3.6 Doesn't Have It

[That One Guy]

You know that's exactly what you're doing when you say the old engine with older tech is more reliable than the newer engine with better tech; right?

I hate to burst your bubbles, but there have been plenty of moment in the auto industry where a great engine in a vehicle was replaced by an inferior one. Sometimes engineering goes wrong. Sometimes people make bad calls.

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[thenewrick]

Alright. Well I'm glad folks are buying up the old inventory! Looking forward to the reviews and performance gains from the eTorque system.

 

[BillyHW]

Yep, this is one reason I'm definitely going with the 3.6L instead of the 2.0L.

 

[thenewrick]

I reckon we'll start seeing reviews for the new 3.6L in the Fall. I have the eeking feeling that the manual transmission will be eliminated with the new 3.6L but who knows.

 

[DanW]

My Google search provided exactly opposite results. Many DI systems now use a partial port injection to clean the intake. Also, this is not hugely important. It's a loss of like 10 horsepower and 5% fuel economy after 50k miles without a cleaning. Huge over-reaction going on here. Non-issue. All new engines are DI/partial DI. They are only using the old Pentastar in the Wrangler to use up old inferior inventory on a profitable new model. You're just trying to convince yourself that buying the crappy old one is better than the new one because it's not as advanced.

The only time I've seen a company make a future engine worse than the existing one was my old BMW where they over engineered the 335i and gave it too much power and made it cheaper/weaker for the newer model years so it wouldn't compete as directly with the M3. But 99.99% of the time, the newer engine is better.

Also that's a good video, pretty much explains everything I said.

What a crock. First of all, the "old" Pentastar was updated significantly just two years ago, to the point that few parts interchange. It really is a redesign.

Fact is, it is a great engine. I've driven it back to back with GM's 3.6, and it feels just as strong. Btw, the gas mileage in the Chevy Colorado, with its DI, and its much more aerodynamic shape, is worse than the JL. Go figure.

Btw, GM redesigned that V6. Why? Bet they had some problems with the early DI setup.

 

[DanW]

I reckon we'll start seeing reviews for the new 3.6L in the Fall. I have the eeking feeling that the manual transmission will be eliminated with the new 3.6L but who knows.

Why would it be eliminated? I doubt they went to the trouble to develop it just to lose it after one year.

 

[thenewrick]

Manual transmissions don't sell well and get lower mpg numbers these days so there isn't a benefit to making them other than to appease a few enthusiasts and international crowds.

DI doesn't make as big of a difference for NA engines. With turbos it makes it a little easier to tune and make big power. Price, power, reliability, pick 2. I'd pick Power and reliability. But, I'm a performance enthusiast. I know most folks just want good mpg and a V8 or V6 badge and as little maintenance as possible. Nothing wrong with that.

 

[DanW]

Manual transmissions don't sell well and get lower mpg numbers these days so there isn't a benefit to making them other than to appease a few enthusiasts and international crowds.

DI doesn't make as big of a difference for NA engines. With turbos it makes it a little easier to tune and make big power. Price, power, reliability, pick 2. I'd pick Power and reliability. But, I'm a performance enthusiast. I know most folks just want good mpg and a V8 or V6 badge and as little maintenance as possible. Nothing wrong with that.

Ok, two parts.

1. Then why did they develop it for the JL? Bad business decision? No. They sell enough of them. They are NOT going to discontinue it after 1 year. That would be dumb. Jeep is not in business to appease anybody. They are in business to make money. The manual transmission sells enough to be profitable. There are manual JK's everywhere. They are much more common than what I see in sports cars. It isn't going anywhere, at least for the next few years. There is no reason, at all, that the BSG 3.6 can't be mated to a manual transmission. Also, if they were just appeasing a tiny minority, they would have just gone with the NSG 370 for one more year. They put LOTS of development into this transmission. Think not? Then explain the many photos of test mules over the last year. Just take a drive in one. I drive mine back to back with the JK and there really is no comparison. The Aisin is a century ahead of the NSG370 in refinement.

2. If it doesn't make that big a difference in NA engines, then why bother? You are making my point for me here. It doesn't make that big of a difference AND it has issues that I don't want or need. That is EXACTLY why I like the Pentastar version they chose for the JL, with no DI.

Sorry, man, I ain't buyin what you are selling, whether with transmissions, or engines.:cwl:

 

[thenewrick]

DI engines don't really have significant issues but they do improve performance and fuel economy and emissions. Yea they're a little more expensive and sometimes need more maintenance to keep maximum performance; sometimes they don't. The main reason they didn't go DI on the 3.6L is because of cost. Customer doesn't want it and will pay top dollar without the feature so it makes sense. There are people who prefer not to buy the eTorque version of the Hemi just for that reason with the new Ram.

I hope they continue with the manual and spread it to more engine options.

 

[BillyHW]

So why don't diesels have these problems with direct injection?

 

[thenewrick]

My guess is they do have the problems and that they might be lessened by the type of fuel/oil vapor getting on the intake valves.

It's really not a problem. It's like worrying about modern gas eating up your fuel lines. Just old grumpy guy hocus pocus.

My BMW injectors were enormous and super loud. My convertible sounded just like a big-rig diesel. I didn't like that aspect of it personally.

 

[56nomad56]

I almost bought a pre-owned 2008 Audi RS4, it only had 35K miles on it at the time. Came home and did research and found out how much trouble carbon deposit build-up could cause the DI V8. And the 13/20 MPGs. Took a pass.

I think VW also had issues with this on their early 1.8T. Haven't heard as much about carbon build up lately, so I'm wondering if manufacturers have sorted out a lot of the problems?

 

[thenewrick]

My BMW was a 2007. I cleaned it with brake cleaner and a brush. Lil messy but not too bad. Alternative was to have a shop walnut blast it for like $400. Throttle felt more responsive afterwards by a tiny amount but didn't notice anything else. Didn't get any more mpg that the computer could tell. No noticeable power change. This was at around 65k miles. Probably about as much good as putting some Lucas fuel treatment in the tank and throttle body cleaning on older cars. Maybe helps a bit, not really noticeable; certainly nothing to worry about.

 

[K9Jeeper]

There’s some seriously rediculous things being said in this thread. DanW, you seem to be on point though.

 

[brandonh]

I was very happy when the news came awhile back that the 3.6 that would be in the Wrangler would be the updated version, but would NOT have direct injection. This video gives a good explanation as to why.

Disclaimer: Some DI engines are doing just fine, long term. I've seen MANY Ford Ecoboosts, for example, that have hundreds of thousands of miles on them and have not had the valve deposit issue cause trouble. My own Ecoboost, which was destroyed when a quick oil change shop improperly installed the oil filter, was torn down by the Ford dealer with 85k miles on it, and they said the valves looked good. For reference, from the first oil change onward, I ran Mobil 1 EP 5w30. A number of oil change intervals went to 10,000 miles, or a little further, so I feel a bit of relief knowing it was in good shape. However, I still am VERY glad not to have DI on my Pentastar.

Enjoy!

Yea, i agree, check this video out about the 2.0 DI

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