Cleaning your intake valve's carbon buildup

F32Fleet · 01-04-2015, 10:07 AM

Quote:

Originally Posted by DrivenByE30

For those in the US, do you think my dealership would do this task if I ask them before my car turns to 50k

Of course, but it won't be free of charge. They do this work all the time.

DrivingPassion · 08-02-2019, 09:28 AM

My dealer used to offer walnut blasting for like $1,200 but they stopped it.
Not sure why.

Lately, there are people using CRC GDI turbo valve cleaner. Not sure if that helps

F32Fleet · 08-02-2019, 04:21 PM

Quote:

Originally Posted by DrivingPassion

My dealer used to offer walnut blasting for like $1,200 but they stopped it.
Not sure why.

Lately, there are people using CRC GDI turbo valve cleaner. Not sure if that helps

Since the interval for the N55 is somewhere over 100k miles I doubt the dealer gets many inquiries

Billfitz · 08-02-2019, 05:39 PM

They may do it, at a price. To prevent having to face that possibility I installed an oil catch can, and am now using CRC valve cleaner as part of my spring maintenance.

oceanview · 08-03-2019, 07:43 AM

I wonder if it's just kind of snake oil, or if driving with high RPM for a while from time to time could prevent/reduce that problem.
- Engine warm
- drive at highway speed, in a lower gear but higher RPM (above 5'000 RPM) for a few minutes.

So the income valve area get's a higher operating temp that could reduce/burn the junk.
Any idea?

Billfitz · 08-03-2019, 08:24 AM

The source of the carbon build up is fully documented, it's oil that makes it's way from the crankcase to the intake manifold via the PCV. Driving habits have no influence on that. An oil catch can, which should be standard in cars with direct injection, is the best prevention.

DrivingPassion · 08-03-2019, 09:51 AM

Quote:

Originally Posted by oceanview

I wonder if it's just kind of snake oil, or if driving with high RPM for a while from time to time could prevent/reduce that problem.
- Engine warm
- drive at highway speed, in a lower gear but higher RPM (above 5'000 RPM) for a few minutes.

So the income valve area get's a higher operating temp that could reduce/burn the junk.
Any idea?

Are you talking about an Italian Tune-up?
Will it work?
Yes and No.

oceanview · 08-03-2019, 11:06 AM

Quote:

Originally Posted by DrivingPassion

Are you talking about an Italian Tune-up?
Will it work?
Yes and No.

Well, not "redline". But just keep it over 4500 or so for a while (gasoline, not diesel)

Normal street driving keeps you in the low RPM mostly <2500rpm while driving, not accelarating.
I doubt that this is good for keeping the engine clean.

Billfitz · 08-03-2019, 11:15 AM

Quote:

Originally Posted by DrivingPassion

Are you talking about an Italian Tune-up?
Will it work?
Yes and No.

Where the intake valves on a direct injection engine are concerned it's a resounding 'No!'. This is especially true with BMW, which runs hotter at low RPM for efficiency, cooler at high RPM to prevent knocking.

DrivingPassion · 08-03-2019, 12:55 PM

Quote:

Originally Posted by Billfitz

Where the intake valves on a direct injection engine are concerned it's a resounding 'No!'. This is especially true with BMW, which runs hotter at low RPM for efficiency, cooler at high RPM to prevent knocking.

That's interesting info.
May I know where you get that from?

Billfitz · 08-03-2019, 02:12 PM

It's been posted here many times.

perryo91 · 08-03-2019, 04:50 PM

Quote:

Originally Posted by Billfitz

Where the intake valves on a direct injection engine are concerned it's a resounding 'No!'. This is especially true with BMW, which runs hotter at low RPM for efficiency, cooler at high RPM to prevent knocking.

Is that why when I'm on a road trip I see oil temp get pretty much at 250 spot on.. But if I'm driving aggressive in the city I will see oil temp drop almost down to 205?->

Billfitz · 08-03-2019, 05:29 PM

That's why. Pre-ignition can be controlled by retarding the timing, but that also hurts acceleration, so when the car senses that you're driving aggressively it cools the engine to control knocking with minimal, if any, retarding of the ignition timing.

F32Fleet · 08-03-2019, 10:27 PM

Quote:

Originally Posted by perryo91

Quote:

Originally Posted by Billfitz

Where the intake valves on a direct injection engine are concerned it's a resounding 'No!'. This is especially true with BMW, which runs hotter at low RPM for efficiency, cooler at high RPM to prevent knocking.

Is that why when I'm on a road trip I see oil temp get pretty much at 250 spot on.. But if I'm driving aggressive in the city I will see oil temp drop almost down to 205?->

Water pump increase the flow of coolant?
I can't remember if there's a thermostat for the oil cooler

oceanview · 08-04-2019, 03:29 AM

Quote:

Originally Posted by F32Fleet

Water pump increase the flow of coolant?
I can't remember if there's a thermostat for the oil cooler

Yes, water pump will increase the flow of coolant. That's what the pump is for. (but I guess your question was more an answer)
The higher the rpm of the pump, the more gallons per time will flow.

Thermostat in the oil filter housing
see #09: https://www.realoem.com/bmw/enUS/sho...diagId=11_4465

I see increasing temp of oil, water and cat. temp (exhaust) with higher rpm.
I think I read somewhere, that driving in SPORT/SPORT+ will also increase the oil/engine temp compared of driving in ECO or COMFORT mode.

Billfitz · 08-04-2019, 08:09 AM

You have it backwards. The engine would run hotter in ECO or COMFORT for better fuel economy, cooler in SPORT/+ for better acceleration. That's why the concept of the Italian Tune Up is flawed. Forty years ago we called it 'blowing the carbon out', driving at high speed in a low gear for maximum RPM. It may have worked then, long before direct injection and computerized engine heat management, but all it would do today is waste fuel.

F32Fleet · 08-04-2019, 04:14 PM

Quote:

Originally Posted by Billfitz

You have it backwards. The engine would run hotter in ECO or COMFORT for better fuel economy, cooler in SPORT/+ for better acceleration. That's why the concept of the Italian Tune Up is flawed. Forty years ago we called it 'blowing the carbon out', driving at high speed in a low gear for maximum RPM. It may have worked then, long before direct injection and computerized engine heat management, but all it would do today is waste fuel.

IMO the "Italian Tune up" would loosen stuck rings.

AtlantaDan · 08-05-2019, 06:06 PM

You can easily handle the walnut blasting on your own. Harbor Freight sells a media blaster for like $50 and you can also get the crushed walnut shells from there as well. $25 for 25 pounds. Hook it to a good compressor, pull the intake off, and go to work. Rotate the engine until the intake valve is closed and the lifter is on the base circle of the cam. (Sounds a lot harder than it is). Blow out the remaining shells with compressed air. Anything that you don't get out will be burned off.

Its far from rocket science. I used to do it to my Focus ST. It took about an hour on a cold engine, and that was with me lollygagging.

08-02-2019, 09:28 AM	#24
DrivingPassion Lieutenant 130 Rep 485 Posts Drives: '15 M235xi Join Date: Nov 2006 Location: WA iTrader: (0)	My dealer used to offer walnut blasting for like $1,200 but they stopped it. Not sure why. Lately, there are people using CRC GDI turbo valve cleaner. Not sure if that helps __________________ 2015 M235i xDrive 8AT
	Appreciate 0 Quote

08-02-2019, 05:39 PM	#26
Billfitz Lieutenant General 8242 Rep 16,079 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	They may do it, at a price. To prevent having to face that possibility I installed an oil catch can, and am now using CRC valve cleaner as part of my spring maintenance.
	Appreciate 0 Quote

08-03-2019, 07:43 AM	#27
oceanview Captain 207 Rep 603 Posts Drives: 335i F31 RWD Autom. Join Date: May 2013 Location: Switzerland iTrader: (0)	I wonder if it's just kind of snake oil, or if driving with high RPM for a while from time to time could prevent/reduce that problem. - Engine warm - drive at highway speed, in a lower gear but higher RPM (above 5'000 RPM) for a few minutes. So the income valve area get's a higher operating temp that could reduce/burn the junk. Any idea? __________________ 335i F31 RWD in SB \|\| Powertrain: Active Autowerke Flash Tune Stage 1 \| AA Charge Pipe \| AA FMIC \| GFB DV+ \| xHD Trans-Flash \| Quaife LSD \| Cyba 3.5" Carbon tips \|\| Chassis: 20" 405M \| Wiechers Strut Bar \| Rear M-Diffusor \|\| Brakes: 18" M-Perf Brake orange 370/345 \| EBC YellowStuff pads all around \|\| Various: LED bulbs: Fog-L. front \| Turn Signal f&r \| Brake L. \| Reverse L. \| Rear L. \| Rear Fog L.
	Appreciate 0 Quote

08-03-2019, 08:24 AM	#28
Billfitz Lieutenant General 8242 Rep 16,079 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	The source of the carbon build up is fully documented, it's oil that makes it's way from the crankcase to the intake manifold via the PCV. Driving habits have no influence on that. An oil catch can, which should be standard in cars with direct injection, is the best prevention.
	Appreciate 0 Quote

08-03-2019, 02:12 PM	#33
Billfitz Lieutenant General 8242 Rep 16,079 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	It's been posted here many times.
	Appreciate 0 Quote

08-03-2019, 05:29 PM	#35
Billfitz Lieutenant General 8242 Rep 16,079 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	That's why. Pre-ignition can be controlled by retarding the timing, but that also hurts acceleration, so when the car senses that you're driving aggressively it cools the engine to control knocking with minimal, if any, retarding of the ignition timing. Last edited by Billfitz; 08-03-2019 at 05:34 PM..
	Appreciate 0 Quote

08-04-2019, 08:09 AM	#38
Billfitz Lieutenant General 8242 Rep 16,079 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	You have it backwards. The engine would run hotter in ECO or COMFORT for better fuel economy, cooler in SPORT/+ for better acceleration. That's why the concept of the Italian Tune Up is flawed. Forty years ago we called it 'blowing the carbon out', driving at high speed in a low gear for maximum RPM. It may have worked then, long before direct injection and computerized engine heat management, but all it would do today is waste fuel. Last edited by Billfitz; 08-04-2019 at 08:17 AM..
	Appreciate 1 waxwing_f311.50 Quote

08-05-2019, 06:06 PM	#40
AtlantaDan Private 65 Rep 70 Posts Drives: 2017 330i Msport Touring Join Date: Jan 2018 Location: Atlanta iTrader: (0)	You can easily handle the walnut blasting on your own. Harbor Freight sells a media blaster for like $50 and you can also get the crushed walnut shells from there as well. $25 for 25 pounds. Hook it to a good compressor, pull the intake off, and go to work. Rotate the engine until the intake valve is closed and the lifter is on the base circle of the cam. (Sounds a lot harder than it is). Blow out the remaining shells with compressed air. Anything that you don't get out will be burned off. Its far from rocket science. I used to do it to my Focus ST. It took about an hour on a cold engine, and that was with me lollygagging.
	Appreciate 1 waxwing_f311.50 Quote