Sponsored

How does Hybrid iForce Max engine cool down the turbos after a hard drive?

STAYFROSTY629

TRD Off-Road Premium
Member
First Name
Scott
Joined
May 5, 2025
Threads
1
Messages
5
Reaction score
0
Location
Richmond, VA
Vehicle(s)
2025 4 Runner
Does anyone know how the Hybrid 4 runners cool down the turbos after a hard drive?

Does the Hybrid system auto stop the engine and turn into EV mode just before parking, or are you able to park and let the engine idle for a minute just to let the oil circulate in the turbo to allow the oil to cool and prevent cooking in the turbo?

I can't find an explanation of the oil cooling process for the 4 runner hybrid.
Sponsored

 

anorphirith

TRD Off-Road
Active member
Joined
Mar 29, 2025
Threads
8
Messages
42
Reaction score
34
Location
West Coast
Vehicle(s)
4Runner TRD off road hybrid
it doesn’t haha, i parked the car and waited in the car before turning it off for the turbo to cool but the engine just shut off my itself almost immediately ?. anyway a potential turbo swap a turbo at 150k miles should take 1500$ and 2h of my own labor. so i don’t really care
 

LLL1990

Well-known member
Joined
Feb 1, 2025
Threads
2
Messages
137
Reaction score
147
Location
United States
Vehicle(s)
Toyota Camry and Ford F-150
What you considered a hard drive was probably a fun ride for the truck. I remember a video of the engineer in charge of developing the engine stating that the coolant intake of the engine was the same size as what Toyota specs for V8s. Unlike the old days, computers monitor every aspect of engine operation. The T24 uses a coolant flow control valve so the computer can direct coolant where it's needed most under varying conditions and it also has an auxiliary oil cooler. The fact that the hybrid turns the engine off is a clear indicator that the temperature of the turbo and engine after your "hard drive" was within normal parameters. If it wasn't the engine wouldn't shut off and the cooling fan would be screaming.
 

Sandlapper

TRD Off-Road Premium
New member
Joined
Apr 6, 2025
Threads
1
Messages
3
Reaction score
1
Location
Yemassee SC
Vehicle(s)
Tundra
Several days ago I pulled into the driveway and decided to make some changes to the multi-function display. Without pushing the big red button, the engine shut down to “idle” with the ac running off the hybrid battery I assume. I made the display changes and I started pushing buttons around the big drive mode knob just for grins. When I pushed the tow/haul button the engine fired and settled into normal idle revs! I have tried this in several scenarios- stopped at traffic lights and stop signs and while driving around town. It appears that this is the answer to letting the turbos spool down with the engine running and pumping oil through the turbo bearings.
Let me know your experience with this please.
 

Nodak

Platinum
Well-known member
First Name
JR
Joined
Jan 22, 2025
Threads
11
Messages
694
Reaction score
450
Location
ND
Vehicle(s)
2014 4Runner
would be nice if it had the same system setup as the tundra.'

air to water intercooler and a dedicated radiator for the cooling system plus electric pumps.

this same cooling for the intercooler also cools the turbo's

the electric pump first feeds the cooling fluid to the intercooler then sends it to the turbo's to cool them. this way if you shut off the vehicle, the electric pumps can still cool the turbo's since its a coolant liquid instead of an air to air cooling system.

reason is that you send it to the intercooler first is that the coolant would pick up too much heat from the turbo and no be effective to cool the intercooler charge


timestamp to adm at ccn

 

LLL1990

Well-known member
Joined
Feb 1, 2025
Threads
2
Messages
137
Reaction score
147
Location
United States
Vehicle(s)
Toyota Camry and Ford F-150
would be nice if it had the same system setup as the tundra.'

air to water intercooler and a dedicated radiator for the cooling system plus electric pumps.

this same cooling for the intercooler also cools the turbo's

the electric pump first feeds the cooling fluid to the intercooler then sends it to the turbo's to cool them. this way if you shut off the vehicle, the electric pumps can still cool the turbo's since its a coolant liquid instead of an air to air cooling system.

reason is that you send it to the intercooler first is that the coolant would pick up too much heat from the turbo and no be effective to cool the intercooler charge


timestamp to adm at ccn

The simple engineering of the turbo 4 with it's air to air intercooler and belt driven water pump is proving to be more reliable than the turbo V6 in the Tundra.
 

Icculus

Trailhunter
Member
First Name
Adam
Joined
Jul 10, 2025
Threads
4
Messages
23
Reaction score
12
Location
NC
Vehicle(s)
2025 IC Trailhunter
This kinda reminds me of the the turbo timer talk when I had my STi and was in the Subaru WRX game. In almost all modern systems the turbo is cooled by the coolant system. Maybe a few seconds of idle before shut off but there is no need for excessive cool down idling periods. Trust me, I guarantee loads this turbo system is seeing is no where close to what my 550hp STi was seeing and turbo cooling was never a problem on that car ;)
 

Nodak

Platinum
Well-known member
First Name
JR
Joined
Jan 22, 2025
Threads
11
Messages
694
Reaction score
450
Location
ND
Vehicle(s)
2014 4Runner
The simple engineering of the turbo 4 with it's air to air intercooler and belt driven water pump is proving to be more reliable than the turbo V6 in the Tundra.
on the 22 tundra, outside of the beginning production run, the turbo issues have been non existent since then and have been resolved.

the issues with the debris during machining and other engine lockups are not related to the turbos, long term wise the the air to water setup is better in the long run since you can have the system kick in the pumps to recirc the water to at least cool the turbo's or pull heat away somewhat plus the turbo cooling system is independent of the other cooling systems, it has it own dedicated radiator.

the turbo's using oil will be harder to cool down after engine shutoff since you need the engine running to pump oil thru the turbo's. unless they have a way to use an electric pump like the tundra to recirc the oil, but that will be way harder since you have the engine to pump thru and then what about oil seepage into the cylinders since most modern engines ( looser piston rings and valve guides slide easier but allow some oil to be burnt to get higher efficiency or higher gas mileage) now a days are built to burn oil.


each has it pro's and con's.

tundra is more complicated and $$$ vs the air to air being simpler and cheaper but you lose out on the ability to run the pumps after engine shutoff.
 

kekecarioca

Trailhunter
Well-known member
First Name
_CAC_
Joined
Sep 11, 2024
Threads
7
Messages
261
Reaction score
187
Location
Texas
Vehicle(s)
2025 Trailhunter 4R -- 1999 4runner SR5 4x4 Manual
I would not worry too much about that.... I would take a LOT to do a hard drive on a 4R. The Electric motor is doing a lot more pull on the acceleration than you think. The Turbo does not stay in full boost very long.
As previously mentioned, the truck decides to shut the engine off pretty often when in Park.
If you are driving "hard", the battery will drain quite quickly, so it will force the engine to stay idling more when the battery is very low and parked. ( my observation).
Also for peace of mind just drive around the block at normal speeds and "cool" the turbo that way since it will not even build much pressure at all.
 

Icculus

Trailhunter
Member
First Name
Adam
Joined
Jul 10, 2025
Threads
4
Messages
23
Reaction score
12
Location
NC
Vehicle(s)
2025 IC Trailhunter
@Nodak Just curious...Nodak Spud receivers, any relation?
 

Nodak

Platinum
Well-known member
First Name
JR
Joined
Jan 22, 2025
Threads
11
Messages
694
Reaction score
450
Location
ND
Vehicle(s)
2014 4Runner
 







Top