Plastic / Composite Intake Manifolds

[ViPER1313]

Wanted to make this so that I didn't hijack Jeff's thread. Am I the only person who thinks that these (along with plastic thermostat housings, plastic water pump blades, plastic valve covers, etc) are a bad idea / a shortcut that car manufacturers are taking that will cost people down the road? I understand that they don't heat-soak, weigh less and are cheaper to make, but won't they warp after 5 to 10 years of use?

[Apoc]

Cars are disposable items, so manufacturers don't have to worry about much more than a 3 year warranty. Once they are old enough to become a problem, they will either be out warranty or so far removed from the original purchaser that the manufacturers won't really be impacted by it.

[xvxax]

I have a plastic intake manifold on my 18 year old car that has never been a problem. It's pretty thick.

I had a plastic tanked radiator, plastic water impeller water pump, and plastic thermostat housing, those were all big problems and pretty substantial design flaws.

[BLINGMW]

When it comes to BMW, clearly there were some problems when they started using a lot more plastic in the engine bay. The infamous E36 cooling system comes to mind. Thermostat housing warped, plastic water pump blades cracked and separated from the shaft, and radiator was damn near a regular maintenance item because of the plastic tanks. All those parts were only good for a few years. However, intake and valve cover turned out ok, cracks were rare. But I think they, like most other manufacturers, have figured it out by now. Plastic's been used for these parts for 15+ years now and it's gotten better. The E46 cooling system, for example, is 100% better and components are proving themselves beyond 8 years and 100k miles.

So I don't consider it a sinister move by the manufacturers. Used properly, and they should be doing it right by now, plastic's the way to go.

[D_Eclipse9916]

Big deal years later, not for manufacturers.

My E36 stuff going from plastic to metal that im immediately replacing....

Radiator
Thermostat Housing
Water Pump

All 3 are CRITICAL in an engine, so why the fuck plastic?

At least they fixed both the thermostat and water pump issue, never fixed the radiator issue.

[Sijray21]

definitely not a huge deal for the manufacturers. this would just be a problem for the late model owners unless you do the intensive research on a car's maintainability to see if there are any serious design flaws or something else irrepairable unless doing serious custom work, you're likely going to get rid of the car or spend a lot of money.

i went through 3 radiators on my old integra due to the plastic end-tanks. i even switched to metal end-tanks one-time and that didn't resolve the issue of the slow coolant leaks from the tanks...

[NTIman]

On Toyotas, I have seen no problem with a composite part that hasn't been involved in an accident.

Radiators maybe, but I've seen very little conclusive proof that many problems are caused by the use of plastic tanks themselves, and not something that would have happened with a metal tank as well.

But we all know that manufacturers have to cut corners to make cars affordable anymore, considering you have to have thousands of dollars worth of safety features to drive the car for you.

[ScottyB]

are there any boosted cars using composite intake manifolds? i can't recall off the top of my head.

[ViPER1313]

I think the new SHO uses a composite intake manifold, and it is boosted.

Plastic radiator end-tanks expand and contract at a different rate than metal - usually you can repair the slow leaks that develop by taking a pair of pliers and re-crimping the tanks to the core. My 20 y/o DSM still is rocking the original radiator (metal end tanks) - no leaks so far.

[Dave]

I don't think there is anything wrong with a plastic manifold, but I'm not a fan of plastic cooling parts.

I also hate big goofy plastic things covering my engine. When I open my hood, I do not want to see a sea of plastic trim; I want to see my damn manifolds and valve covers.

[BLINGMW]

I also hate big goofy plastic things covering my engine. When I open my hood, I do not want to see a sea of plastic trim; I want to see my damn manifolds and valve covers.

well yeah, I'm with you on that. This has got to stop:

:vomit:

:vomit:


:vomit: sorry, I hope I didn't ruin anyone's lunch, I should have posted those as NSFW

On Toyotas, I have seen no problem with a composite part that hasn't been involved in an accident.

Radiators maybe, but I've seen very little conclusive proof that many problems are caused by the use of plastic tanks themselves, and not something that would have happened with a metal tank as well.

yeah, I think it can be engineered right or wrong, metal or plastic. I've seen all metal radiators split at the seams too (Jess' old Honda Accord) and I've seen plastic that lasts forever. :dunno:

[NTIman]

Definitely, junk is junk whether its made out of plastic or metal. I would prefer metal for everything, but plastic has come a long way.

I agree on the plastic covers, I really hate when they bring the toyotas with the L logo on the front in with their big ass shields covering everything. so basically, people will pay $5-10K more for a car that has an L badge instead of a T badge, and for some stupid looking covers to make their engines not look like engines.

[ViPER1313]

Cars are disposable items, so manufacturers don't have to worry about much more than a 3 year warranty. Once they are old enough to become a problem, they will either be out warranty or so far removed from the original purchaser that the manufacturers won't really be impacted by it.

I really wonder how much this mindset pays off in the long run. 6 and 7 y/o cars make up a good portion of first cars / primary vehicles to younger people who cant afford to buy new, but later in life will make purchase decisions on new cars based off the reliability of the older cars they used to have. People buy a lot of new Hondas and Toyotas because of the reliability of cars they made 15 years ago. To me, it seems like certain manufacturers are shooting themselves in the foot 10 years down the road by cheeping out on things like cooling systems and intakes on cars made today.

[ScottyB]

I also hate big goofy plastic things covering my engine. When I open my hood, I do not want to see a sea of plastic trim; I want to see my damn manifolds and valve covers.

well yeah, I'm with you on that. This has got to stop

i see your German cars and raise you the Japanese! ze goggles, zey do nossing!

[Steve85]

but then what would you paint?

[Sijray21]

they need to make more engine bays like this:

[BLINGMW]

they need to make more engine bays like this:

no, sorry, fail, that engine is turned the wrong way. And what's all them silly pipes for? :dunno:

i see your German cars and raise you the Japanese! ze goggles, zey do nossing!

Good play sir, good play. But I still see some iky iky coil packs, ew! I can only counter with:



I guess without that cover, people would be like, "there's not even an engine in here!"

[WRXtranceformed]

I also hate big goofy plastic things covering my engine. When I open my hood, I do not want to see a sea of plastic trim; I want to see my damn manifolds and valve covers.

well yeah, I'm with you on that. This has got to stop

i see your German cars and raise you the Japanese! ze goggles, zey do nossing!

Haha that looks somewhat familiar! :lol:

BTW my IM is made of magnesium alloy :mrgreen:

[Mike]

it's gonna catch fire. like magnesium wheels do.

[fiveoh2go]

I also hate big goofy plastic things covering my engine. When I open my hood, I do not want to see a sea of plastic trim; I want to see my damn manifolds and valve covers.

Modern engine bays for the most part are ugly with all the various wiring, hoses, vaccum lines, fuse blocks, ect. I'd rather not look at that crap. :dunno:

no, sorry, fail, that engine is turned the wrong way. And what's all them silly pipes for? :dunno:

no, sorry, fail, that engine is lacking a few cylinders.


Here ya go...