Are Plastic Parts a Problem?

[Cujet]

I have no problem with plastic parts. Unless they are exceedingly difficult to replace.

Will they last 100 years? Not much chance of that. But they do provide good service for most people .

 

[SeaJay]

Ya think?

 

[wpod]

Plastic works great until it fails.

 

[PimTac]

Metal is no guarantee of quality either. Lots of metal water pumps failed back in the day.

 

[JTK]

Like said, power train plastics could be good, but they're designed to a price point for your average vehicle. Look at pentastar cooling system parts or oil filter housings for example. Or GM valve covers and plastic cooling system bits. Horrible reliability.

 

[PiperOne]

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.

Good thing, if everything had a 3408 in it the country would be out of diesel fuel in a week! Sounds purty though!

 

[Finklejag]

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

Yup, I unsubscribed from him last year because I thought the same.

 

[KrisZ]

I can only guess that his YouTube career is becoming the primary source of income, instead of being a mechanic. I liked his early videos, he wasn’t as preachy back then.

Regarding plastics, I take it that cars from 40s, 50s and 60s, 70s didn’t break. They used almost no plastics, so they must’ve been dead nuts reliable

 

[brages]

Yes, I've had experiences with plastic parts failing.

It's an engineering challenge to use polymers effectively in a car, and when the challenge isn't met, customers suffer.

 

[zzyzzx]

I've never had a metal car part get brittle and fall apart.

 

[BMWTurboDzl]

I can only guess that his YouTube career is becoming the primary source of income, instead of being a mechanic. I liked his early videos, he wasn’t as preachy back then.

Regarding plastics, I take it that cars from 40s, 50s and 60s, 70s didn’t break. They used almost no plastics, so they must’ve been dead nuts reliable

IMO the big difference is that when a plastic part fails it requires the replacement of the entire part rather than a small part. The failure can either occur spontaneously or during the removal of said part.

Take cooling hoses with their plastic connectors. A break at the connector will require replacement of the entire hose rather than a say just a new tension spring. Cracked radiator neck requires new radiator rather than brazing the crack.

Of course efficiencies in manufacturing have made vehicles more labor intensive to service which increases the probability of plastic components breaking during their removal in order to gain access to repair/replace an unrelated piece.

 

[KrisZ]

IMO the big difference is that when a plastic part fails it requires the replacement of the entire part rather than a small part. The failure can either occur spontaneously or during the removal of said part.

Take cooling hoses with their plastic connectors. A break at the connector will require replacement of the entire hose rather than a say just a new tension spring. Cracked radiator neck requires new radiator rather than brazing the crack.

Of course efficiencies in manufacturing have made vehicles more labor intensive to service which increases the probability of plastic components breaking during their removal in order to gain access to repair/replace an unrelated piece.

I understand how the plastics break.
My point is that vehicles, despite plastics are in order of magnitude more reliable and longer lasting than the cars from the "pink glasses" era. They make a lot more power and use less fuel. Plastics are one of the reasons it could happen.

Yes they will fail from time to time, but overall they are a net positive IMO.

 

[dave940]

The problem with plastics probably lies in the cheapness of manufacturing. I had the misfortune of working for several months after losing a job when the economy cratered in 2008, extruding window frames, door frames, etc. The process involved cutting samples constantly, measuring a dozen or more parts of each cross section, and occasionally scrapping product based on these measurements. Let's just say that the remedies taken to get back toward quality were crude, too much like an art instead of science. You eventually settled for something less than what you wanted just to get stuff out the door. I had previously worked in chemical manufacturing, where quality and product specs were much stricter. After several months of this, I was ready to work somewhere else.
So that was plastics extrusion. Maybe this is an apples vs oranges comparison, but I doubt that casting metal is that loosy goosy.
"

 

[twouvakind]

"Plastic has been in engines before I was born. Nylon timing chain gear sprockets"

American Motors comes to mind, 1968!

 

[ls1mike]

It isn't plastic...all cars are a problem.

 

[Kurtatron]

I'd still take a metal intake over a plastic one. Something meant to only house other mechanical tidbits, give me heavy metal. If it has some sort of major weight advantage, like a hood or body panels, plastic is acceptable. Can you imagine plastic transmission housings? No thanks.

 

[aquariuscsm]

I think it depends on where the plastic is and what it's used for. I would rather see only metal and glass. The only car parts I've ever had break were plastic.

 

[CR94]

"Plastic has been in engines before I was born. Nylon timing chain gear sprockets"

American Motors comes to mind, 1968!

So what did AMC do then? GM and Ford timing sprockets made earlier than that frequently failed.

 

[dave940]

So what did AMC do then?

Went out of business, probably because they made ugly cars... too many Ambassadors and Pacers, not enough AMX and Javelins.

 

[dishdude]

Went out of business, probably because they made ugly cars... too many Ambassadors and Pacers, not enough AMX and Javelins.

Clearly you're not an automotive historian.