[vinen]

My buddy drives a 911 turbo and has to cool down the turbos by letting the car idol before turning off the engine. He says it is a necessary step with any turbo engine, otherwise the oil does not continue to run through the turbos while they have a chance to cool down. Otherwise the oil would just frye inside of the turbos (not good).

Is letting the engine run while the turbos have a chance to cool necessary with the 335i?

[Pedal2Floor]

Originally Posted by vinen

My buddy drives a 911 turbo and has to cool down the turbos by letting the car idol before turning off the engine. He says it is a necessary step with any turbo engine, otherwise the oil does not continue to run through the turbos while they have a chance to cool down. Otherwise the oil would just frye inside of the turbos (not good).

Is letting the engine run while the turbos have a chance to cool necessary with the 335i?

How old is his Porche? This has not been true for most modern turbos in a long time. Unless it specifically says so in the manual, it is not required for modern turbos. The reason for this is at one time because engines used Dino Oil. With Synthetic oil it is not necessary because there is no "coke" up effect that used to happen before Dino Oil. When this was a problem people used "Turbo Timers" that would do the cooling down for you. On a modern turbo when the engine is shut off, coolant continues to circulate due to thermal convection, helping to prevent long-term heat-related damage to the turbo bearings.

Its not necessary unless your buddy has an old Porche that required Dino Oil and will certainly not be required for the 335i.

This question has been answered many times in Motor Trend and C/D. At one time one of the Acura sites had a very good write up on this but I can't find it anymore.

[vinen]

okay, thanks for the info. I thought it seemed odd...his is an 02 and maybe he is just misinformed or being ultra cautious over his baby...

[r3amir]

The BIG question is: Are the Turbo engines as reliable as other engines?

[Pedal2Floor]

Originally Posted by r3amir

The BIG question is: Are the Turbo engines as reliable as other engines?

Yes -- what would make a Turbo less reliable? The boost on the 335i is not exactly very high. The new compression ratios are not in the startosphere.

In the past, reliability was more do to the turbos themselves. A lot of R&D and lot track time has made them reliable. If you go back to the 70s, there was no question to the 2002ti's reliability. When Nelson Pekay won the Formula 1 championships in the first ever turbo powered car, there was no issues.

While turbos do run hotter, cooling, coolant systems and synthetic oils have all been designed for the high heat.

Answer me why they would be unreliable?

[Bush Pilot]

Originally Posted by Pedal2Floor

Yes -- what would make a Turbo less reliable? The boost on the 335i is not exactly very high. The new compression ratios are not in the startosphere.

In the past, reliability was more do to the turbos themselves. A lot of R&D and lot track time has made them reliable. If you go back to the 70s, there was no question to the 2002ti's reliability. When Nelson Pekay won the Formula 1 championships in the first ever turbo powered car, there was no issues.

While turbos do run hotter, cooling, coolant systems and synthetic oils have all been designed for the high heat.

Answer me why they would be unreliable?

The answer to the original poster's question is a resounding, "Yes.". The rationale is that the turbo motor is more complex with more parts that can fail. In addition since the turbo runs hotter the whole system experiences a greater range of heat cycling thereby putting more heat stress on the entire system.

[stewbets]

Originally Posted by Bush Pilot

The answer to the original poster's question is a resounding, "Yes.". The rationale is that the turbo motor is more complex with more parts that can fail. In addition since the turbo runs hotter the whole system experiences a greater range of heat cycling thereby putting more heat stress on the entire system.

THANK YOU!

I've been waiting FIFTEEN YEARS for this answer.

[Saif2018]

Originally Posted by stewbets

THANK YOU!

I've been waiting FIFTEEN YEARS for this answer.

[Bush Pilot]

[whyzee125]

The reason our cars have an electric water pump is to keep coolant cycling after cooldown to allow the turbos to cool down slowly. I never wait for the car to cool down and just turn it right off unless I've been pushing it in the last few minutes or the oil temps are above the usual 200 deg range. If they're like 230-240, I'll let it idle for a minute or drive very gently the last mile.

[Bush Pilot]

Originally Posted by whyzee125

The reason our cars have an electric water pump is to keep coolant cycling after cooldown to allow the turbos to cool down slowly. I never wait for the car to cool down and just turn it right off unless I've been pushing it in the last few minutes or the oil temps are above the usual 200 deg range. If they're like 230-240, I'll let it idle for a minute or drive very gently the last mile.

I agree with your philosophy. That said, my oil temperature is typically 215-220 F under normal driving. I did see 250 - 260 at the track.