Just curious to see how long people let their cars sit before they shut off their engines.

I dont have a turbo timer. But i ...
Usually let it sit for 1.5 - 2mins with fans on.

Is this a good time limit to let the turbos cool down VIA the circulation of oil?

How long does the average turbo timer setup for? And how does a turbo timer actually work..? does it keep your engine running ?

 

^^^ same. Depending on how its driven too... if driven harder.. I will drive around for a cool down with the bonnet popped a little, than idle for 2 minutes...

 

1) Don't get a turbo timer. Period. If you search, you'll read all about horror stories w/ turbo timers. Don't be that guy

2) Don't leave the car idling. There's no cool air flowing through the engine bay when the car is standing still, yet the block is still producing heat. In fact, once you come to a dead stop w/ the engine running, engine bay temps SKYROCKET. You're actually making things HOTTER than simply turning off the car once you arrive.

3) So PRIOR to arriving, simply coast into your neighborhood w/o boosting. Those 30 sec. before getting to your crib are more than enough to allow the turbos (which are water AND oil cooled) to cool down.

4) If you wanna simply cool the plastics in the engine bay, you can do the fanswitch mod to leave the fans on WHILE THE ENGINE IS OFF.

That's a recipe for disaster my friend. One of those times you won't be so lucky and the hood will unlock and pop open, bend backward, and dent your roof, take out your windshield, breaking/bending the hood in the process, and since you can't see, you're more than likely to run into/sideswipe something at the same time...all for doing something that won't help the car cool at ALL. Popping the hood a bit and driving w/ it like that won't do ANYTHING to help your temps...trust me...unless you have some radiators/oil coolers in that tiny gap in between the hood & the bumper?

 

^^Actually the engine will become more hotter from heatsoak rather than just coming to a dead stop and idling.

With heatsoak, there is no heat transfer there is no more flow, thus raising under hood temps dramatically.

What i do is i run the fans on after i shut the engine down for about 1 or 2 minutes, 3 or 4 minutes if i boosted. If its really severe, say in the summertime, ill try to find shade and pop the hood and leave it up for about 5 minutes.

 

And like I said, running the fans afterward with the engine OFF and popping the hood will take care of that just nicely.

 

+1 for just taking it easy for a couple minutes before you arrive at your destination, and +100000000000000 for the fan mod. I have it run automatically for about 5 minutes if my temps are over 90*C at shutdown. If I'm staying near the car, I'll pop the hood up until the fans turn off, and that's it.

I gave the turbo timer I found for free to a friend who needed it. Aside from buying the daily, that was the best FD-related decision I've made.

 

I always, ALWAYS let the car have at least a mile or so of 'off-boost' running, particularly if I've been running it hard, before even letting it idle, for example on the way to work or coming back home, the last couple of miles I just basically coast. When pulling into my garage, I have a fan that I pull right up to and turn on, pop the hood and let those temps cool down fast.
Point is, if you have been boosting at all, you simply MUST allow the cooling system to be able to dissipate the heat. If you've been off boost, then idling doesn't do a whole lot.

 

after goin out for a spin and doing some boost runs i tend to coast the last mile or so on neutral to my house then ill let it sit idle for a minute.

i read in the FAQs its not good to immediately turn the car off as soon as you park it so i take the time to do minor things before hand like grabbin my CDs and hiding my wolf 3D hand unit under the seat since ppl around here will jack anything for their crack money.

 

Also try disengaging the transmission (putting it into neutral) if your path allows you to coast in such a fashion. I have an oil temp gauge, and I can tell ya that oil temps PLUMMET once you disengage the tranny.

That's in the context of hard driving/boosting. If you coast to your destination, you can turn it off once you arrive with no ill effect.

 

So many stories, i know if you search you will also get alot of threads saying you dont need a turbo timer because these are liquid cooled turbos and it isnt neccessary. I still have no idea what to believe.

 

You did but you also said letting the car idle will make things HOTTER than simply shutting off the engine in your number #2 statement.

Thats when i came with the heatsoak statement. You should of eliminated your #4 statement and used that to continue the #2 statement. Then it woulda made more sense to the OP.

 

That's a recipe for disaster my friend. One of those times you won't be so lucky and the hood will unlock and pop open, bend backward, and dent your roof, take out your windshield, breaking/bending the hood in the process, and since you can't see, you're more than likely to run into/sideswipe something at the same time...all for doing something that won't help the car cool at ALL. Popping the hood a bit and driving w/ it like that won't do ANYTHING to help your temps...trust me...unless you have some radiators/oil coolers in that tiny gap in between the hood & the bumper? [/QUOTE]

The hood is still attached, its just sleight popped... not completely as in loose, you can't lift it up! Its only down my road.. but thats for the tip

 

#1 has officially been lost because of #2's numbered comments

Yes, I know exactly what you're talking about. You're still running a considerable risk for absolutely NO gain. But hey, whatever helps ya sleep at night

 

I agree with everything you said. Except #4 which IMO keeping the fans off while the car is off does not do a thing to cool the engine. Yeah it cools the coolant in the radiator but since the water pump is off, that cool coolant never makes back into the engine block lol. Basically all you end up doing is extracting heat from the radiator into the engine bay.

I just cruise the last few minutes of my destination.

 

Those 2 minutes arent going to do ****

 

correction

 

I've got an original engine with over 108k with original turbos to prove you wrong. Fact prolonged periods of idling accelerates plug fouling and carbon build-up. It also increases the engine temps with no air flowing through the radiator and oil coolers. It's pointless to sit in your driveway while your engine is idling when you can simply keep the engine in a vacuum state for the last 1/2 mile or so before shut down. The engine will infact cool down much much faster this way.

 

Coasting is a little extreme for some that live in flat areas. Driving in a vacuum state will also easily accomplish the same thing. Just take it easly the last 1/2 mile or so.

 

Oh I know it won't help cool the block really. But I'm sure popping the hood and leaving the fans will help w/ plastic parts & hoses longevity some (again, not a crucial factor, but still haha).

Of course. Just sayin what you can also try IF possible lol. No one's askin the impossible

~Ramy

 

i do that to only when im going down my street so im not going any faster than 25 max.. is a bad idea for normal streets tho

 

So having the fans on after the car is off will have no substantial difference than if you were to just shut the car off and leave?

I been doing the fan switch after drive while the car is off for 3 years now and every single time i saved the car from being heatsoaked to an extreme temperature. Only time i dont do the fan switch is when for short errands (like cvs, food store, autozone etc) and each of those times the temperature was much higher than if i were to stay in the car for a couple of minutes running the fans while the car is off.

I say there is a difference.

 

I did the fan mod so when I park my car in my carport, I pop the hood. The fans run and as long as the t-stat is open the coolant WILL circulate a bit. The hot coolant will displace coolant lower in temp in the radiator forcing it into the block.
We all have our little rituals, but as long we follow the basics ( light driving after boosting before parking your car ) anything you do to encourage airflow after parking can only help cooling the engine.

 

I've consistently observed 10C+ lower coolant temps at startup after sitting hot for 15-20 minutes when leaving the fans running with the hood closed (i.e. stop the engine and go into a store). On my car, temps tend to max out after 10 minutes or so at 105-107C during the summer if the fans aren't left running after shutdown; otherwise they are around 95C with the fans. This is all with the hood closed. Keeping air flowing through the radiator cools that large mass of coolant and keeps air moving under the hood.

Of course I always pop the hood after shutting it down in my garage. Running the fans with the hood open doesn't make any appreciable difference that I've seen - just leaving the hood open allows the heat to escape, and cool air is drawn in from underneath. The fans help when the hood is closed because they keep air moving, so it doesn't saturate and cook the plastic and rubber components.

 

Yup, you're alot like me. I only pop the hood W/O the fans on in my driveway, i shut car off, pop the hood and go inside.

If ambient temps are extreme, even at work i pop the hood for a couple of minutes with the fans on. I dont care if im over doing it or if im weird, whatever. I know that extra time of cool air helps out. Sure beats the hood closed with all that heat trapped.

 

Oh, so all the mechanics and experts who recommend the fan mod and turbo timers are wrong because a "newbie" says it's not necessary. Got news for you ANYTHING you can do to lower the ambient temperature under the hood is a good thing. Anybody that says otherwise is delusional.

Opening the hood is definitely a plus because it allows the super hot air, that would otherwise be trapped under the hood, to escape thereby lowering the ambient temp around the engine, thereby cooling the engine more quickly. Common sense.

Second, moving air across the radiator, even hot air, will have a cooling effect. Want proof...get yourself a fan and point it at your face. Did the temperature of the air drop suddenly? NO, the temperature of the air did not change but it feels cooler because it is moving. It's called forced convection cooling and regardless of what you guys think forcing air across the radiator does cool the radiator, thereby reducing the ambient temperature and again cooling the engine more quickly. If the engine is running then the coolant flow through the block cools the engine even more than if it weren't running. So idling with the fans running definitely will cool the engine more than turning the engine off.