Problems With Plastic Intakes

[Daox]

Similar to the drive by wire thread you started, nearly all engines use plastic intake manifolds these days. Forced induction engines may be the only exception. So, you pretty much can't buy a car without a plastic intake manifold. I'm sure there are problems with parts, especially newer technology parts. Honestly, I've never heard of people having problems. As its been mentioned they've been around for over 15 years. They aren't going away.

Jim, I commend you on your thoroughness in evaluating a new vehicle, but nit picking at features that every single car on the road has today is kind of pointless.

[gone.a]

Every manufacturer uses plastic intake manifolds and they usually last the life of the car, sometimes they fail as any part can but they are a proven and reliable design with low failure rates. The most reliable cars on the market use them (Lexus, Toyota, Acura, etc) as do cars of the highest caliber. Saying they are a poor design is like saying you need to change oil every 3k. It's an outdated idea from a bygone era.

[daleWV]

I have a 15 year old Dodge Stratus with 175,00 miles. The rest of the car is pretty much junk but there is certainly nothing wrong with the plastic intake manifold.

[Cani Lupine]

Plastic intake? Common. But the plastic valve cover wasn't expected.

[Jimmyess333]

Thank you for all the replies and information.
I see the plastic intake and valve cover are not things I can change at this time.
However, if metal replacements should emerge in the future I would like to perform that swap.
Thanks again.

[Mistah JT]

Every manufacturer uses plastic intake manifolds and they usually last the life of the car, sometimes they fail as any part can but they are a proven and reliable design with low failure rates. The most reliable cars on the market use them (Lexus, Toyota, Acura, etc) as do cars of the highest caliber. Saying they are a poor design is like saying you need to change oil every 3k. It's an outdated idea from a bygone era.

Not sure what 3k in Australian Metric system is, but they suggest changing oil every 10-15 thousand KM. I can assure you oil does not look very good by 10,000 kms. I get my car serviced once a year, and I dump the oil and put fresh in at the 6th month. It is black by then. So i don't think it's an outdated way of thinking.

[inuvik]

Not sure what 3k in Australian Metric system is, but they suggest changing oil every 10-15 thousand KM. I can assure you oil does not look very good by 10,000 kms. I get my car serviced once a year, and I dump the oil and put fresh in at the 6th month. It is black by then. So i don't think it's an outdated way of thinking.

10k would be about 6200 miles. I've been changing mine every 5000 miles. It doesn't look bad but that doesn't really mean much. Just had it changed and zero consumption. I'm very impressed with the 3A92.

[Cobrajet]

Thank you for all the replies and information.
I see the plastic intake and valve cover are not things I can change at this time.
However, if metal replacements should emerge in the future I would like to perform that swap.
Thanks again.

Why not just change the stock plastic intake IF it fails rather than changing it for no reason other than it being plastic? The only reason I can see for having one of these fail is poor design. On the Mirage, the intake is on the front of the motor...kept well away from the worst heat of the engine and bathed in cool air when the car is moving.

All metal intakes are good for nowadays is adding WEIGHT.

[Angrybeaver]

Subaru has been using plastic intake manifolds on the WRX for years, and there are plenty of people making big power with them.

[MightyMirageMpg]

for the record here guys, the vortec trucks, grand marquieses (?), Chevy sonics, cruze etc and even the "almighty lsx" motors did have issues with plastic manifolds.

ford even issued a redesigned intake it got so bad, and anyone spraying (nos) an early ls pretty much swapped to aluminum

his idea has merit and opens up performance options as well. i just don't think it's viable financially. intake design is 10 fold harder than exhaust.