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What is that all about? How do you clean an intake manifold, doesn't gas flow thru it all day long?

when taking my Jeep into the dealer for the air bag recall they wanted to clean the intake manifold or suggested that the intake be cleaned along with other items.

what does this entail?

thanks...
 

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What is that all about? How do you clean an intake manifold, doesn't gas flow thru it all day long?

when taking my Jeep into the dealer for the air bag recall they wanted to clean the intake manifold or suggested that the intake be cleaned along with other items.

what does this entail?

thanks...
Your PVC systems dumps all the waste gases in to the intake. It looks like oil but it is actually combustion byproducts. These are actually acids that won't hurt the plastic parts they do tend to pile up over time. One of the reason people use oil catch cans is to eliminate this.

I would not spend money doing these though unless you where also having spark plugs changed. I do all the work myself so it cost nothing but time.
 

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The only thing going thru the intake is air and oil vapors. The oil vapors get burned off through the combustion chamber. This is a feature on all engines.

Fuel is injected by the injectors. Years ago, The injection was at the bottom/ end of the intake. Now a days, the injectors are mounted in the heads.

So the old intake cleaning is not really needed any more. But some still try there best to sell it.
 

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use top tier gas and you will be fine. Intake cleaning is a pure profit service item. Think about it they don't have to do anything and no-one will ever know. If you are worried run a bottle of Techron thru once and while.
 

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The only thing going thru the intake is air and oil vapors. The oil vapors get burned off through the combustion chamber. This is a feature on all engines.

Fuel is injected by the injectors. Years ago, The injection was at the bottom/ end of the intake. Now a days, the injectors are mounted in the heads.

So the old intake cleaning is not really needed any more. But some still try there best to sell it.
Have you had your intake off? You can pour crap out of it with as little as 50K miles, I did. While the theory is sound that application is fubar'd. There a 2 breather ports, one pre throttle body and one post. When these gases hit the cooler intake stream they condense to a solid state and leave a block oily like substance behind.

Also none of these engines are DI, they are port injected. At least with port injection the intake valve stay clean where as DI the intake valves get coated with this crap and then it gets baked on.
 

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Have you had your intake off? You can pour crap out of it with as little as 50K miles, I did. While the theory is sound that application is fubar'd. There a 2 breather ports, one pre throttle body and one post. When these gases hit the cooler intake stream they condense to a solid state and leave a block oily like substance behind.



Also none of these engines are DI, they are port injected. At least with port injection the intake valve stay clean where as DI the intake valves get coated with this crap and then it gets baked on.
No, I have not had my intake off. Haven’t needed too.

Yes, the vapors can condense and get sticky to create the black oily film. It’s not really hurting at all.

As for pouring stuff out the intake.... never in all my years of engine build/rebuild, or repairs. Have I ever poured anything out during disassembly.
 

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Discussion Starter #7
thanks all for the comments...

I am not going to worry about this then, but next summer I will look at this while I am changing out my spark plugs when the intake needs to come off anyways.
 

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Yes, there will be oil residue from the PCV system in the intake manifold, but generally it's not a big issue on port injected engines like the pentastar, as the fuel injectors will keep the intake valves clean enough. If this were a Direct Injection engine, it would be a totally different story.

Also, there are some intake manifold designs that have pockets which absolutely do pool up oil, but not all of them do. I don't recall if the intake manifold design of the pentastar is prone to this or not.
 
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the pentastar uses differently designed intakes for different platform applications
in the wrangler, its the oddball design with the TB in the front
most platforms have a TB position that sits toward the rear of the block.

from a simple eye test ,it would look like the jeep intake layout would flow better.
being it has a shorter airbox run and a straighter shot into the plenum.
tho there are no statistical numbers to back that up, as performance is the same across different platforms.
now along the same lines oil catch cans are widely used on many non jeep pentastar applications .almost mandatory in some circles.
while some people in the jeep circle do use catch cans , excess oil doesn't seem to be as noticeable a problem.
that would be a possible result of a better flowing intake
 
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The only thing going thru the intake is air and oil vapors. The oil vapors get burned off through the combustion chamber. This is a feature on all engines.

Fuel is injected by the injectors. Years ago, The injection was at the bottom/ end of the intake. Now a days, the injectors are mounted in the heads.

So the old intake cleaning is not really needed any more. But some still try there best to sell it.
Two weeks ago, girlfriend took her 2018 Grand Cherokee in for oil change... she got an estimate for the recommended 30K mile service. She has the MaxCare Lifetime warranty. They quoted her $250 to clean the injectors... and another $150 to flush the brake fluid.

Obviously I told her to decline the additional service work. But I keep wondering, what they do under the hood to clean the injectors?

I still have the factory installed injectors in my '91 Cherokee.. never been "cleaned" or removed, 28 years later it passes strict Calif smog with zero problems.

.
 

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Two weeks ago, girlfriend took her 2018 Grand Cherokee in for oil change... she got an estimate for the recommended 30K mile service. She has the MaxCare Lifetime warranty. They quoted her $250 to clean the injectors... and another $150 to flush the brake fluid.

Obviously I told her to decline the additional service work. But I keep wondering, what they do under the hood to clean the injectors?

I still have the factory installed injectors in my '91 Cherokee.. never been "cleaned" or removed, 28 years later it passes strict Calif smog with zero problems.

.
I would probably never pay to have injectors cleaned but there are benefits to having it done. But at the price they ask for the service I would just as soon as buy a machine and do it myself. The on vehicle cleaner kits cost less than $200 and the larger testers/cleaners unit start at around $400 and can go way up from there.
 
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At 50k I ran a can of Mopar Combustion Chamber Cleaner through it, pulled off my throttle body, cleaned it all up and also removed the intake manifold and cleaned it all out.

This was completely unnecessary overly maintaining the Jeep. I just enjoy that kind of thing. Ill do it again at 100k
 

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the pentastar uses differently designed intakes for different platform applications
in the wrangler, its the oddball design with the TB in the front
most platforms have a TB position that sits toward the rear of the block.

from a simple eye test ,it would look like the jeep intake layout would flow better.
being it has a shorter airbox run and a straighter shot into the plenum.
tho there are no statistical numbers to back that up, as performance is the same across different platforms.
now along the same lines oil catch cans are widely used on many non jeep pentastar applications .almost mandatory in some circles.
while some people in the jeep circle do use catch cans , excess oil doesn't seem to be as noticeable a problem.
that would be a possible result of a better flowing intake
Performance (HP) is not the same across the platform. FCA engineers have confirmed that the HP gains in the Charger, Challenger, etc., are strictly due to increased airflow due to the different intake designs. :)

Despite the four variants of the 3.6 already being sold — rear drive (290 hp), AWD (292 hp), FWD (283 hp), and Challenger (305 hp), there are just two head designs, two intake manifolds, and one set of internal components, including cam and pistons (this probably changed when they added the Ram setup, 305 hp, though the rep said the main advantage in the Ram was the space available for the exhaust), according to an SAE article by Paul Weissler. The Challenger's 13 horsepower increase is due to "a more aggressively designed intake air system" which increased airflow from 214 to 220 g/s.
https://www.pentastars.com/engines/tech.php
 

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The Wrangler JK has an absolutely ridiculous exhaust layout.
 

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And oil soaked air filters don`t help.(K-N)
I've been running K&N filters across many different vehicles for 20+ years. Forced induction and naturally aspirated, turbo'd and supercharged. Open cone types, drop-in replacements in stock airboxes, etc. I would estimate close to 500,000 miles in total, without ever having an issue with dirty throttle bodies, issues with O2 sensors, MAF sensors, etc. If you know how to properly clean and dry them, and properly oil them, and let them dry before re-installing, you won't have any issues. I would assume that anyone who has ever had any type of issue related to them, has a hard time figuring out how to put gas in their vehicle, and has no clue of the proper way to maintain a K&N filter. :mooning:
 

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Performance (HP) is not the same across the platform. FCA engineers have confirmed that the HP gains in the Charger, Challenger, etc., are strictly due to increased airflow due to the different intake designs. :)
not the same exact , but close enough to be insignificant .
the charger /challenger also uses a different exhaust and that also leans toward different HP numbers.
but the jeep , the charger/challenger and the mini van all have basically the same numbers +/- 10 hp

the only intakes I've see that show any increased flow are the aftermarket ported intakes.
but even with a ported intake the gains are minimal without also changing the
air box intake runner, TB and exhaust
 

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not the same exact , but close enough to be insignificant .
the charger /challenger also uses a different exhaust and that also leans toward different HP numbers.
but the jeep , the charger/challenger and the mini van all have basically the same numbers +/- 10 hp

the only intakes I've see that show any increased flow are the aftermarket ported intakes.
but even with a ported intake the gains are minimal without also changing the
air box intake runner, TB and exhaust
The 3.6 in the Wrangler is 285 HP, the 3.6 in the Challenger is 305 HP. I'll take the extra 20 HP thank you. If you want to discount the SAE article quoted on Allpar, that's your prerogative. :)
 
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