Fact or Crap: A hotter engine puts more wear and tear on parts

bikes4u · #21 05-25-2009, 01:05 PM

OP--I remember studying this in auto shop class. The higher the temps the less wear on engine parts. One of a few reasons why todays thermostats are 200+, thermostats 30yrs ago were always 180.

Yaris Hilton · #22 05-27-2009, 06:13 AM

True, the higher engine temperatures reduced buildup of sludge, piston and ring deposits. I have an old textbook on oils and lubricants with dramatic comparison pictures making the point. (Of course, running one too hot can also cause oil oxidation problems.)

I'm very surprised to find that my 2009 Yaris is supposed to have a 184°F thermostat, and an electric fan that cuts on at 204°F. I expected it to run hotter.

Sulfuric · #23 06-02-2009, 04:16 PM

I don't know the specs that my 94 Corolla has regarding the thermostat and when the fan kicks on, but I've had the fan come on multiple times. I have a lower grill block and i live in Florida so it's hooooooot already but the needle never moves past the halfway mark. I don't think the needle is broken because a cold start has the needle at the bottom.

I feel like the needle should be moving high than it ever goes, but I don't know what temps the needle ever represents.
P.S. I P&G enough that I can sometimes keep a slightly lower temp than usual...that probably cancels out my grill block enough to avoid damage.

Elixer · #24 06-05-2009, 01:29 AM

Quote:

Originally Posted by jhu

Interesting point. I don't have a grill block on my car and the water temperature gauge stays pretty much constant once it gets up to about 190 F, even with NICE-on/off P&G. How much of a difference does that make?

I really doubt that this makes much difference. It takes a long time for your engine to warm up not only the fluid in the engine, but also the fluid in the radiator once the thermostat opens. It takes a large transfer of heat to increase/decrease the temperature of water, so turning off the engine for a long time, even a few minutes, isn't going to greatly affect the water temperature. Combine this fact with the fact that the engine coolant temperature is controlled by the thermostat, and I doubt you'll see much change as you drive. What I would imagine causing wear is the large temperature changes made when warming the car. This would also mean that those in colder climates would need to more often replace seals, piston rings, etc due to their higher delta when warming up their cars. Granted this is purely speculative, I wonder if there are some statistics out there to prove what I'm saying?

Ford Man · #25 06-06-2009, 01:39 AM

Years ago they claimed that a cold start caused as much wear to an engine as driving it 500 miles. As long as you're not running extremely hot I don't think it's going to make a noticeable difference in the longevity of the engine. I have my cooling fan on one of my '88 Escorts on a toggle switch and never turn it on unless the temperature gets to about 230* and it has 494K+ miles on the original engine and has never been rebuilt.

Yaris Hilton · #26 06-06-2009, 04:35 PM

A 50/50 mix of glycol antifreeze and water with a 15 PSI pressure cap boils at 265°F. With a 70/30 mix it goes up to 276. So you've got a good bit of leeway at 230, and I'm surprised at the 184° thermostat and 204° fan on my Yaris. Do they think people are going to run plain water with no pressurization?