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Discussion Starter · #1 ·
I m thrilled by MultiAir because it's such an elegant and simple in concept solution to adjusting intake valve timing and amount of air allowed into each cylinder.

I am worried, because, while simple in concept, the required hardware pribably is complex and may be failure-prone. This concern is admittedly based on conjecture.

I would expect the inatke valve control solenoids to be to most fragile component in the MultiAir engine. This electromechanical/hydraulic component has to be highly stressed and I wonder about its projected average servie life and replacement cost. Multiply by 4.

On the positive side, I am pretty sure that a failed solenoid will not cause the kiss of death between pistons and intake valves as happens in an interference engine. I expect a failed solenoid to simply result in cylinder deactivation (no intake air, fuel will be shut off automatically). A solenoid that fails in the open position will simply allow the roller-tipped cam follower ("finger") follow the cam lobe profile, which means the cylinder can either keep working , although without the finely tuned adjustments to opening and intake air volume, but maybe in such a case the cylinder will also be simply deactivated.

Does anybody know more about MultiAir than speculation or does anybody have any thoughts?


https://www.youtube.com/watch?v=Td9Gz_h7Qpg
 

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Discussion Starter · #3 · (Edited)
And yet, here you are reading and replying to my obscure concern. Or are you implicitly telling me to get lost with my obscure concerns? It's hard to tell on a forum, so please clarify. If you think I am being overy sensitive to your remark, please realize I have seen forum trouble start exactly this way before, and I am not keen on it happening again. It's better to lay the cards on the table early on.
;)

I plan on buying a Trailhawk (Omaha Orange, with cold weather package and hood decal, maybe trailer hitch. I plan of adding a bull bar, auxilliary lighting and a roof basket). My worries are not obscure to me, since they concern problems I have run into before. I do like to be informed about possble pitfalls. I'm not fan of foul Easter eggs! I also like to learn from past experiences. I want to have adventures with my car, I don't want the car to be the adventure.

Are the discussion points below what you are referring to when you say "You seem to be worrying about some obscure stuff"?

Headlights: I have had unusable, outright dangerous DOT-spec headlights on several cars that made me install e-codes. I want to be able to see properly in the dark.
Tires: I have had terrible OEM tires that were slicker than an oiled pig on goose droppings.
Rust protection/undercoating: I have seen new cars with the unprotected chassis of a 1936 VW Beetle.
Engines: I have owned cars with interference engines and saw the same engines drop dead like flies around me.
Engine Oil: It's a hobby of mine.

If anybody has a problem with me addressing the above and similar apparently obscure discussion points, please let me know now, before I have settled into this forum. If my posts offend, bore, or are otherwise objectionable, I shall hang my coat elsewhere. Trust me, I won't be offended.
 

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And yet, here you are reading and replying to my obscure concern. Or are you implicitly telling me to get lost with my obscure concerns? It's hard to tell on a forum, so please clarify. If you think I am being overy sensitive to your remark, please realize I have seen forum trouble start exactly this way before, and I am not keen on it happening again. It's better to lay the cards on the table early on.
;)

I plan on buying Trailhawk. My worries are not obscure to me, since they concern problems I have run into before. I do like to be informed about possble pitfalls. I'm not fan of foul Easter eggs! I also like to learn from past experiences. I want to have adventures with my car, I don't want the car to be the adventure.

Are the discussion points below what you are referring to when you say "You seem to be worrying about some obscure stuff"?

Headlights: I have had unusable, outright dangerous DOT-spec headlights on several cars that made me install e-codes. I want to be able to see properly in the dark.
Tires: I have had terrible OEM tires that were slicker than an oiled pig on goose droppings.
Rust protection/undercoating: I have seen new cars with the unprotected chassis of a 1936 VW Beetle.
Engines: I have owned cars with interference engines and saw the same engines drop dead like flies around me.
Engine Oil: It's a hobby of mine.

If anybody has a problem with me addressing the above and similar apparently obscure discussion points, please let me know now, before I have settled into this forum. If my posts offend, bore, or are otherwise objectionable, I shall hang my coat elsewhere. Trust me, I won't be offended.
Not in any way telling you to get lost.
Just wondered as I said. do you have a renegade or are you considering buying one.
No need to get so touchy.
 

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Discussion Starter · #5 ·
I did answer your question up there. As for me responding to you calling my concerns obscure, I consider them basic concerns for a car guy. You are of course at liberty to call my concerns anything you like. And while I may seem touchy, I already explained my response in my initial response. I just don't want to find out after, say a few months, that the majority of members finds my posts obscure rather than relevant. I don't yet know these forums well enough to know if the majority here is hands-on car guys or just owners shooting the breeze. If the latter is the case, please someone tell me, because that's the wrong place for me. A PM will do, if responding in public is too embarrassing.
 

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The MultiAir module is only one in 1.4 engine and 2.4 engines, so if something goes wrong all the module will be changed.
There were some problems with earlier modules around 2010 (if I remember well).
Modules are (were?) manufactured by Schaeffler, that also made the industrialization of the product.

It must be used engine oil as manual specifications since MultiAir is an hydraulic system that uses engine oil to work.
 

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Variable valve timing has been around for a while. MultiAir is just one way to do it. I don't think there is much to worry about. I have a vanos selenoid go bad on a BMW and even then it was less than $100 to fix. Since this hydrolic system appears to be harder to get to I would imaging it costing a bit more to fix. Since the video does not talk about exhaust valves being controlled by the system there shouldn't be anything to worry about.
 

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The multiair valve train appears to be pretty solid. I have had three cars now with the multiair set up (2 Fiats and the Renegade) and have been spent much time in blogs about the three vehicles. Honestly, I had concerns as well when I purchased my first Fiat 500 Sport. By the time (one year later) I purchased the 500 Abarth, my concerns were gone. The multiair system really does work well and I have not seen any issues what so ever in the blogs about the multiair valve train.
 

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Ive had the multiair unit fail on my Alfa Romeo Giulietta, symptom is a very lumpy tickover. Above tick over it ran fine, so it won't leave you stranded. (Valves default to closed on failure)

If you look on the Alfa forum there have been a few failures on early cars (around 2010), there has been at least three variants of this unit so fingers crossed it is now 100% reliable.

My experience certainly did not put me off having a Renegade with the same engine as my Alfa.
 

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Not all readers of this forum are going to know enough about the "obscure" systems in the Renegade to appreciate or reply to your questions.... that doesn't mean they are any less legitimate. The Renegade will be the most technically advanced car I have ever purchased and I have many concerns about the long-term reliability of it's components. Unlike my 1952 Willys Jeep, there is very little I can do maintenance-wise on the Renegade - indeed, this will be the first car I've owned where I suspect I will often need to take it to the dealer for maintenance rather than my local mechanic.

While waiting for my Jeep to arrive I have scanned this forum, read the horror stories, been inspired by the positive reports and experiences and in general tried to educate myself as much as possible. I appreciate postings such as Lamont's because the replies are often quite enlightening.

BTW - Happy Thanksgiving to all who celebrate the day!
Tim
 
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