How much wear during warm-up?

[G-MAN]

I guess I should qualify what I wrote above. That 4500 rpm redline for a cold engine would only apply to that BMW family of engines. Obviously if the rated redline for your engine is say 5500 rpm rather than 8250 rpm, the corresponding "cold redline" will be much lower than 4500 rpm.

On my 300M, which has a 6500 rpm redline, I generally try not to exceed 3500 rpm until the temp gauge has been at the normal level for at least 5 minutes.

 

[Scout1]

Thanks AEHaas, once again you have provided some very interesting technical data on my question... Exactly what I was hoping for! Opinions are a dime a dozen, but I love hearing about actual testing

Guess my pappy was right, keep the RPM's down till she warms up! I think I'm gonna have to get an oil temp gage in my truck...

 

[kapps]

I see the same thing on my MINI. I recently installed an oil temp gauge and it doesn't get to steady-state (~225F) until 20-30 minutes after startup. On a warm/hot day, I can usually get the gauge to read over 180F within 10 minutes. The MINI has one of those water-oil heat exchangers.

I keep my rpm's down under 3k until oil reaches 180 and I try not to push it until it's over 200.

 

[RI_RS4]

My Audi RS4 engine has a 7000 rpm limit, until the engine reaches 120F. Then it opens up to 8250. The engine also has a water/oil intercooler, to get the oil up to operating temperature as fast as possible. I was told specifically by a representative of Audi that this is done to limit fuel dilution, by raising oil temperature after start up and idle, so that fuel in the oil will vaporize off.

 

[buster]

I drive an hour each day to work. I start the car, keep the rpms below 3k for 5 minutes that it takes me to reach the highway. After 5 minutes, I'm doing at least 80mph for 45 minutes. No way to avoid that. So my question is, would driving 80mph after 5 minutes be considered too fast too soon? No way for me to avoid it regardless but I thought I'd ask.

 

[G-MAN]

Quote:

---

My Audi RS4 engine has a 7000 rpm limit, until the engine reaches 120F. Then it opens up to 8250. The engine also has a water/oil intercooler, to get the oil up to operating temperature as fast as possible. I was told specifically by a representative of Audi that this is done to limit fuel dilution, by raising oil temperature after start up and idle, so that fuel in the oil will vaporize off.

---

My 300M has a water/oil intercooler, too. I'm thinking more and more that the reason Chrysler spec'd 10w30 for this engine (and still does to this day) is that it has a fuel dilution issue (though not as bad as the RS4). Every UOA I've ever done on this car has had elevated fuel levels. If the engine has an inherent fuel dilution issue, my constant short trip driving doesn't help--but it's nice to know that intercooler is helping get the oil temp up faster than it otherwise would.

 

[G-MAN]

Quote:

---

I drive an hour each day to work. I start the car, keep the rpms below 3k for 5 minutes that it takes me to reach the highway. After 5 minutes, I'm doing at least 80mph for 45 minutes. No way to avoid that. So my question is, would driving 80mph after 5 minutes be considered too fast too soon? No way for me to avoid it regardless but I thought I'd ask.

---

How many rpms at 80 mph? On my car 80 = 2500 rpm.

 

[daman]

How much wear during warm-up?

IMO hardly any,disassemble a engine and bearings, you'll see
a light coating of oil on the crank and bearings, all over.


use the right weight oil and there should be none to nil.

 

[AEHaas]

Wear is load and RPM dependent. As long as you try not to press it hard then you are doing all you can to minimize the wear.

Running with thin oil as I do I am comfortable stepping on it after the oil is up to 140 F or more. I do not run sustained RPM until 170 F however.

aehaas

 

[Steve S]

As usual remember the oil temps are greater as the oil gets pumped smooshed between the bearings ,cam ,valvetrain ,cyl, walls under the pistons etc. The only cold start wear to worry about is when the ambient temps are way too cold for the viscosity of oil used. For example straight 30 when it is 10f degrees and the oil takes a real long time to reach the pump .Think a real thick milkshake as sucked through a straw . Too much worry about things that should not be worth worrying about.To avoid cold start wear don't start your car

,cold starts happen .Remember the the online experts are like the news casters on TV . They may sound like they know what they are talking about but do they really.

 

[gwood]

Quote:

---

Wear is load and RPM dependent. As long as you try not to press it hard then you are doing all you can to minimize the wear.

---

Really all that it comes down to IMO.

 

[Craig in Canada]

Quote:

---

A pre-oiler only circulates oil prior to start-up, right? That's not my question... I want to know if I should baby my engine till the oil heats up.

---

Actually, driving conservatively before everything is warmed up isn't just about oil. Engines are machined to fit properly at full operating temperature with all parts thoroughly heat soaked. As the engine warms up, some parts expand more/faster than others. During partially warmed up conditions your oil is flowing but the parts don't fit quite right.

Does it account for visible or noticeable wear? Maybe, maybe not, but that's my habit in all temperatures. Start up, wait anywhere from 0 to 15 seconds and drive off conservatively. Even in -30C (maybe I'll give it 15-30s in that extreme).