lol at those requirements.
What new car is built well, with metal parts?
- Thread starter ProbeGT
- Start date
Interesting. Is that the 1.8l? The newest Corolla is supposed to have the Dynamic force - which would bet this engine (with polypropolene valve cover.. Are there different options possibly?
I think the M20 bit means it's a 2.0L. Where I was cheap I got the older 1.8L. Which has an aluminum valve cover but plastic intake. EGADS! maybe I should be worried?
I'm not sure about it being "well built" but I think it'll run longer than I care to drive it...
The plastic expansion tank, radiator ends (upper radiator hose connection specifically), dual valves and probably some other stuff I am forgetting on the 94 BMW are all plastic and all regularly fail at around 60k mile interval. I don’t know if this is because they are plastic, or because of the high cooling system pressures the car runs for emissions. These are the only parts on the car that have failed catastrophically. The cap to the oil filter canister is plastic, the housing is metal, and that has been fine. Intake manifold is also plastic, no issues. So put me in the camp of not being a big fan of plastic parts subject to high temperatures fluids or heat cycling. That being said, the 4Runner uses plastics in all the same parts and after 70k miles there have been no failures. Ram is too new to tell. E28 is traditional tank like German build.
When we raced, we had two professional mechanics on the team. One was a tech for a large Mercedes dealer, the other had his own Euro car shop. Both said the move to plastic was for weight and cost, nothing else, and certainly not for reliability.
The new cars have many excellent qualities but there are certain aspects that can shift a great deal of overhaul cost to the customer, and cause catastrophic reliability issues when they fail. I consider plastic one of those things but there is nothing to be done at this point. I am just grateful I don’t have an Audi with non-metal oil control rings.
When we raced, we had two professional mechanics on the team. One was a tech for a large Mercedes dealer, the other had his own Euro car shop. Both said the move to plastic was for weight and cost, nothing else, and certainly not for reliability.
The new cars have many excellent qualities but there are certain aspects that can shift a great deal of overhaul cost to the customer, and cause catastrophic reliability issues when they fail. I consider plastic one of those things but there is nothing to be done at this point. I am just grateful I don’t have an Audi with non-metal oil control rings.
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I have to wonder: if they put it onto a maintenance schedule to replace those parts every 60k, would it be a big deal? Seems expensive and unnecessary, but, if they just wrote it there and made it a routinely replaced part--would anyone care?
The components are expensive - you are basically talking about an all new cooling system when you add in the water pump.
What's expensive? number I mean. Some cars need $1k or more for a timing belt every 100k. Are we talking $2k every 60k or $100 every 60k?
Much closer to the 2k if paying a shop. Probably close to 1k if you are selective about parts and avoid genuine chinesium.
Then a layer of spray Fluid Film is you friend to help seal off moisture/corrosive salts. I live in a Minneapolis suburb and we inundated with salt in the winter. When I bought my car new in 2018, I sprayed the whole under carriage with Fluid Film ( in the summer) and a light dusting of sand and dust grabbed onto the gel and help shield off any "wear off" from winter splash clean-off, with exception of direct tire sand flip up/blasting. My car has no rust or corrosion because of this application to the whole under carriage.
I don't even consider component material composition when I buy a vehicle. If the part fails, then I replace it. The Durango has had a new radiator with plastic end caps replaced, the all metal A/C condenser, engine mounts, plastic oil filter housing, and alternator in 183k miles. Not a big deal.
Some cars should like the Chevy Cruze....Change all underhood plastic at 60K!!
Polypropylene is one of many kinds of plastic. Same stuff that' used to make yogurt containers and plastic garden furniture - those plastic chairs that get so brittle that a leg breaks off after a few months of sun exposure are made from polypropylene. When you recycle, anything with #5 in the triangle is polypropylene. It's a step or two above polyethylene (the simplest plastic polymer) but still not that durable.
It can be a big deal. Any of the listed parts breaking/cracking under load is a potentially catastrophic event for the engine. Loss of oil, loss of coolant, etc. By the time you notice the failure it may be too late.
Ouch. At BMW part prices, double ouch.
I owned one and agree that the design of some of the plastic parts was bad, but that's not the fault of the material. I did have to replace the PCV valve which is build into the valve cover, because it leaked. Bad design.
The gasketing is different though. If that metal intake had the same type of intake gasket that plastic intakes use, it would probably not be leaking.
Plastic is less reliable, but there issue is way overblown imo.
Like on the bmw forums one guy was replacing his radiator every 60k because it had plastic. You're tossing an OE Made in France rad for a cheap South Africa replica just because it has plastic ends, just like practically every other car on the road?
If it was actually an issue every BMW should be smoking from the hood on the side of the road.
I suspect the expansion tank failures could be from overfilling. The way the float is designed you can overfill the tank to the brim, and it will read just above full level.
Like on the bmw forums one guy was replacing his radiator every 60k because it had plastic. You're tossing an OE Made in France rad for a cheap South Africa replica just because it has plastic ends, just like practically every other car on the road?
If it was actually an issue every BMW should be smoking from the hood on the side of the road.
I suspect the expansion tank failures could be from overfilling. The way the float is designed you can overfill the tank to the brim, and it will read just above full level.
How many BMWs have you owned?
To be fair the issue may not be solely the plastic but also the cooling system pressure. It is unclear. But you might be a little less dismissive if you had gotten stuck when the upper radiator connection let’s go or when the expansion tank takes a dump. They are essentially wear items on certain series and years of BMWs, and I say that as a fan of the marque.
I had once replace the OEM plastic / aluminum radiator with a CSF "all metal" radiator. It had a slow leak that gradually cause me more headache and finally is replaced with another OEM style plastic / aluminum radiator under warranty. Sure in theory metal is "better" but the quality is not there. They didn't weld it right from the beginning.
So far my record: plastic tank radiator last about 160k miles, low quality metal about 60k miles.
I would just look for a car from a good reputable brand and call it a day. You can use the most durable material and if the engineering is cut by the accountant it will still be crap. Plastic engineered correctly can be better than metal engineered wrong.
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My pressurized plastic coolant tank all lasted 120k, 15 years if they are from Toyota and Lexus. The one failed at 90k was from Ford and replaced with a Dorman that looks like an updated Ford (interior reinforcement instead of just a hollow tank with nothing reinforcing internally).
It is the R&D. You need more R&D and testing to do things right regardless of material. Buy a car from a company that would not cut corner is important.
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It makes total sense from a manufacturer’s perspective to use more plastic parts. Cheaper to produce and design. They can easily last the 10 years needed for a warranty period.
But there’s a reason why bridges and buildings won’t be made of plastic anytime soon. Plastics do degenerate with age, that’s a fact. Metals, as long as protected from corrosion, do not. When you’re making a product to last 15 years, plastic makes sense. Making it to last 40 years like a building? Stick with metal.
Metal is a better material for longevity, but be real, how many car owners want to keep a car 30+ years? Why should manufacturers consider those outlier customers? Again, most reasonable answer is more plastic parts.
But there’s a reason why bridges and buildings won’t be made of plastic anytime soon. Plastics do degenerate with age, that’s a fact. Metals, as long as protected from corrosion, do not. When you’re making a product to last 15 years, plastic makes sense. Making it to last 40 years like a building? Stick with metal.
Metal is a better material for longevity, but be real, how many car owners want to keep a car 30+ years? Why should manufacturers consider those outlier customers? Again, most reasonable answer is more plastic parts.
