Are Plastic Parts a Problem?

[Shel_B]

During the course of a video, the Car Wizard observed and commented upon the plastic parts he's finding in many makes of cars these days. I didn't realize the plastics were as pervasive as The Wizard seems to be describing. As an example, he shows a water pump from a Mini. The clip follows. I'm wondering what you think about Wiz's comments and the overall increasing use of plastic.

 

[97K15004WD]

Car Wizard is an auto mechanic. No dig at all, but he is no engineer. He is commenting on things the doesn't know about regarding the design and the parameters of the design.

OEM is designed to specification, whether by the manufacturer, SAE, etc. As a result, the product meets "specification".

What we don't know, and what he is alluding to, is the original specification of the design and what the engineers were to designing to, and for.

Anything can be "over-engineered" to last forever, but who want's a water pump that lasts 100 years when the car is only designed to last five years. I would venture to say that the specific car engineers are designing to cost limits to "enhance" profitability of the car in question.

If the purchaser's of the Mini don't like the plastic parts, they will either quit buying the Mini, or they will upgrade to the metal parts as the plastic parts fail. This is the age old argument of "planned obsolescence".

Remember, as a "buyer" you are not setting the initial specification, you are only approving that spec with your dollars.

 

[RooflessVW]

@Shel_B I feel that, as a longtime member here, you should know exactly how this thread is going to go.

I find it moronic that he considers a 15 year old water pump to be "junk."



"I can snap the chintzy plastic easy"

You got many screwdrivers in your cooling system bud? What a bozo.

 

[atikovi]

Plastic parts will make it through the warranty period just fine, and it seems that's all they care about.

 

[skyactiv]

He is a Youtuber that earns money from making videos. He has to come up with ideas on new videos to make money. This one just happens to be moaning about plastic parts and he knows a lot of viewers will agree with his so-called opinion and take interest in the video.

He is no different than a lot of other Youtubers.

Plastic has been in engines before I was born. Nylon timing chain gear sprockets.
The all metal water pumps on cars from yesteryear like a 70's GM weren't exactly long lasting.

 

[skyactiv]

And I'm a semi mechanic for a fleet. I don't go, boy, I hate all these modern emissions I gotta deal with, i'm a simpleton and wish every truck had a Cat 3408 in it.

 

[BMWTurboDzl]

Plastic is
- Cheaper to produce
- Provides greater flexibility in design
- Lighter than an aluminum alternative.
- Saves labor during assembly

The only issue with plastic is embrittlement however plastic parts have come a long way in that regard over the decades.

 

[Astro14]

I said this in another thread, but it applies here:

“The “plastic” cap on my wife’s Volvo has lasted 21 years and 296,000 miles - so far. A steel cap would have been a rusty mess by now, given our regular salt water exposure.

Composite doesn’t mean cheap, and it doesn’t mean bad. The F/A-18 center fuselage is made out of composite. Holds up to carrier launches, landings, and high G maneuvering.”

Quit thinking of plastic as cheap, or fragile.

In many cases, “plastic” out performs metal. Having flown a “plastic” airplane - plastic can be super strong, durable, and high performance, as long as it’s engineering properly.

 

[atikovi]

Composite doesn’t mean cheap, and it doesn’t mean bad. The F/A-18 center fuselage is made out of composite. Holds up to carrier launches, landings, and high G maneuvering.”

Quit thinking of plastic as cheap, or fragile.

In many cases, “plastic” out performs metal. Having flown a “plastic” airplane - plastic can be super strong, durable, and high performance, as long as it’s engineering properly.

Airplane parts are made to a different standard. If a $150 Mini water pump was made to THAT standard, they would probably have to charge $800 for one. Think $600 toilet seats.

 

[Astro14]

Airplane parts are made to a different standard. If a $150 Mini water pump was made to THAT standard, they would probably have to charge $800 for one. Think $600 toilet seats.

You may have missed the part of my post where I mentioned a plastic car part that has lasted 20+ years and nearly 300,000 miles.

 

[RooflessVW]

Airplane parts are made to a different standard. If a $150 Mini water pump was made to THAT standard, they would probably have to charge $800 for one. Think $600 toilet seats.

The "quality" of aircraft parts varies wildly.

In general, parts that keep the plane in the air are very robust. Everything else is the cheapest **** you've ever seen. It's why I laugh when I see auto guys complaining about cheap plastic parts or interiors.

Most of these guys would do $10k in damage if they had to remove a plane interior or accessories.

 

[atikovi]

You may have missed the part of my post where I mentioned a plastic car part that has lasted 20+ years and nearly 300,000 miles.

I was comparing what it would cost to manufacture an automotive water pump to an airplane part standard. Didn't miss that at all.

 

[researcher]

What is also needing to be said is the term "plastic" incorporates many composites some of which can be as durable/strong or better than metal. Just as new epoxies are gluing cars together and can be stronger than welding. Yes some "plastics" can be cheap quality, but so can metal.. Goes both ways..

 

[Trav]

Not all plastics used in the automotive world are good or even decent, who can forget nylon timing gear teeth, plastic coolant elbows and plastic manifold gaskets used on a wet manifold, plastic timing chain guides, etc. None are of the quality of the composites used in aviation which usually contain carbon fiber, F1 cars use similar composites.
German cars VW and BMW in particular have had issues for years with plastic cooling system parts. MB. Saab, Volvo and others seem use better plastics for the same parts.

 

[IndyIan]

I guess the main issue is that plastic parts can be very bad, either too soft or too hard or gets brittle in 3-6 years...
Automotive metal parts have traditionally not to be very bad, and even the ones that rust quickly can be preserved for a long long time with a few drops of oil every once in a while.
Plastic and composites could be great for 15+ years, but its sure hard to tell by looking at them, especially when they are all new...
It would be good if Sandy Munro & Associates or a similar company tore apart every new model and evaluated the long term durability of the materials used. Especially now with cars so complicated and difficult to repair, some bean counters $5/unit cost saving hidden deep in there can turn into a very predictable $2k repair 6-8 years into ownership....

 

[MasterSolenoid]

Briggs & Stratton makes Cam Shafts out of plastic.
I believe the engine I put on my snow-thrower has one.
I saw the patient listing the hours of life expectancy and figured I'd get 25 years (minimum) out of the engine.

https://www.jackssmallengines.com/jacks-parts-lookup/part/briggs-stratton/594090?msclkid=2964dba564c412f48de1bfa0978f0ad7

 

[wings&wheels]

The "quality" of aircraft parts varies wildly.


Most of these guys would do $10k in damage if they had to remove a plane interior or accessories.

Who doesn't love Royalite?

 

[SaberOne]

Mixed bag for me. Following the military, I worked for a defense engineering firm, and I know a lot of composites are stronger, lighter and so forth. Even so, I prefer steel over plastics any day. The worse for me? I absolutely hate limp-dic plastic bumpers.

 

[Snagglefoot]

My 2000 Ford Taurus had a metal upper intake manifold and plastic valve covers. My 2005 Taurus has a plastic upper intake manifold and metal valve covers. Progress.

 

[jeepman3071]

I used to like the car wizard, but it seems every video inches closer to being on the Scotty Kilmer level of things.