After a real hot day or spirited driving does anyone

[audimotion]

lift their 135's engine hood to alleviate heat? I've noticed that my 1'er gets hot as hell after driving stop and go, or spirited...just wondering if doing the hood pop in the garage would help preserve engine parts over time.
My 04 S4 4.2L V8 gets hotter than any vehicle I've owned..enough that my feet get hot. Anyway, alot of S4 owners would lift the hood after a drive to help cool down. Am I just being neurotic??

[Rico135i]

I do after every track session and when i arrive home. Car cools down much faster.

[Cuz5150]

BINGO!!! You and I must be the only ones. I too a former A4 1.8tmq owner, i did this for the last 11 years.
In the summer months when i pull the 1er in the garage, pop the hood every time. On a really hot days/spirited driving, open hood/and place a floor fan in front of the car for better cooling.
Heat cycles is what "KILLS" every thing under the hood. From vacuum lines to rubber hoses, to all the different plastics, down to the engine block......
This sounds very OCD, but i works, My A4 looked like a brand new car under the hood......
So...........yeah, you are not the only one

[1SerieStud]

It's a turbocharged engine...all components were designed to withstand high temperatures as this is common in force-inducted setups. I see the effort in what you do, but frankly, I don't believe it will make any difference over time in terms of engine durability. Just look at how quickly your engine's rpm's fall on a cold startup, indicative of little time it takes for the engine to come up to operating temperatures.

[b1g1an]

Originally Posted by Cuz5150

Heat cycles is what "KILLS" every thing under the hood.

I assume you don't mean that as cooling it quicker would be irrelevant.

[1SerieStud]

Originally Posted by b1g1an

I assume you don't mean that as cooling it quicker would be irrelevant.

Precisely. The engine will heat up and cool down no matter what; how quickly it heats up or cools down is irrelevant.

[Kcyrusm]

Originally Posted by 1SerieStud

Precisely. The engine will heat up and cool down no matter what; how quickly it heats up or cools down is irrelevant.

I disagree. If anything, things should cool down slow, rather than fast. This is why most turbo cars recommend leaving the car running for a bit before turning off so it cools at a safer rate. We don't have to though, BMW took care of that for us with an automated cool down period after you turn the car off. I'm not educated enough to remember if its a pump or what, but yeah, just remember reading it in the past.
-my opinion

[1SerieStud]

Originally Posted by Kcyrusm

I disagree. If anything, things should cool down slow, rather than fast. This is why most turbo cars recommend leaving the car running for a bit before turning off so it cools at a safer rate. We don't have to though, BMW took care of that for us with an automated cool down period after you turn the car off. I'm not educated enough to remember if its a pump or what, but yeah, just remember reading it in the past.
-my opinion

All opinions welcome of course, and we could always agree to disagree, however, cooling down in say 2 hours (hood open) versus say 3 hours (hood closed) is completely irrelevant to durability. What would actually have a negative effect on the engine would be if someone dumped a bucket of iced water into the engine compartment right after shut off...this could even cause certain components to crack.

Also, the act of leaving the car running before shut off is referred to as "turbo-timing", which allows for oil/coolant (depending on the type of turbo) to continue circulating through the ducts inside the turbocharger to help it achieve a safer cool down - this helps preserve the shaft seals/bearings.

[KingOfJericho]

You're probably doing more harm than anything by doing this. Leave the hood down and let the temp slowly decrease.

[Kcyrusm]

Originally Posted by 1SerieStud

All opinions welcome of course, and we could always agree to disagree, however, cooling down in say 2 hours (hood open) versus say 3 hours (hood closed) is completely irrelevant to durability. What would actually have a negative effect on the engine would be if someone dumped a bucket of iced water into the engine compartment right after shut off...this could even cause certain components to crack.

Also, the act of leaving the car running before shut off is referred to as "turbo-timing", which allows for oil/coolant (depending on the type of turbo) to continue circulating through the ducts inside the turbocharger to help it achieve a safer cool down - this helps preserve the shaft seals/bearings.

No, I agree with you. I was just refering to the turbo when saying it does matter how fast or slow things cool/heat up. I'm aware it is called turbo timing I also agree that opening the hood or closing it probably makes no difference.

[kgaler]

I come from electrical engineering, not mechanical or automotive but at least with electronics fast changes in temperature are a problem. It comes from parts that are bonded together (bolted, soldered, whatever) that have different rates and direction of size change with temperature.

I have no idea whether opening the hood helps or not but it might keep the paint from getting too hot and discoloring.

[KingOfJericho]

Originally Posted by kgaler

I have no idea whether opening the hood helps or not but it might keep the paint from getting too hot and discoloring.

That's the only possible benefit I can see.

[RimasRS]

Slower changes in temps is better than quick cooling

[BKarre]

I would think of it like Heat-Treating metals - if you heat it up and rapidly cool a material, such as a quenching bath, you cause embrittlement of the chemical structure.

I agree that you should let the car cool on it's own just to make the change that extra bit more gradual.

Of course opening the hood isn't like throwing ice water on the engine, but given the experiments I've run and things I've seen I'd like it to be as slow and gradual as possible.

[TMR013]

While there may be some benefit, I doubt it's enough to be significant. Heat is just one of the variables in the enviroment that determines how fast a car wears.
I drive around in 100+ temps 5 months of the year, probably means my car will wear faster than somebody in Canada, but I doubt not by enough for them to really care about it.

[mackeroni]

Originally Posted by RimasRS

Slower changes in temps is better than quick cooling

What happens in the winter? I drive in temps down to 0 degrees F. I would guess that these conditions cool everything off pretty quickly, especially if the wind is blowing.

Am I killing my car?

[1SerieStud]

Originally Posted by mackeroni

What happens in the winter? I drive in temps down to 0 degrees F. I would guess that these conditions cool everything off pretty quickly, especially if the wind is blowing.

Am I killing my car?

lol not at all. I hate to put it in these terms, but without offending anyone, this thread is as irrelevant as it gets. Winter, summer, whatever, no matter how much longer or shorter it takes to cool down, it is not an abrupt change for the engine.

[Focusedintntions]

I do it only at track days in between sessions only.