Walnuts

[Trixie86]

CR has an article on using crushed walnuts to clean intakes on a GDI engine. Thoughts?

 

[Truck Norris]

I believe this is common. I've never had it done but did discuss it as an option at a BMW dealership once looking at one of their direct injection used cars. I've been thinking the G70 3.3 may need it before 100,000 km give or take. Guessing here. Would love to hear someone's opinion on this.

 

[Trixie86]

I believe this is common. I've never had it done but did discuss it as an option at a BMW dealership once looking at one of their direct injection used cars. I've been thinking the G70 3.3 may need it before 100,000 km give or take. Guessing here. Would love to hear someone's opinion on this.

Inject into twin turbos?

 

[Truck Norris]

Very manual process I believe. Google "walnut blasting carbon buildup" or something like that.

 

[Don88]

Bringing back memories of my '54 Pontiac Custom Catalina and the cleaning the carbon out of the straight eight.

 

[bubbaG80Sport]

This is sandblasting with walnuts (of course ground into a powder) . Sand would be to abrasive on the metal. GDI engines are prone to carbon buildup on the valve intakes. A common repair/maintenance on GDI engines at 50-100K miles is to remove heads and walnut blast the carbon off the intake channels/valves. This work is a labor intensive and $$$$$$$$.

Coincidentally, I ran a can of GRC intake cleaner through my 2018 G80 Sport 3.3T this weekend. Doing this regularly and having a oil catch can installed on PVC side of intake manifold I'm hoping to eliminate the need for walnut blasting down the road.

 

[Richard Mississauga]

I tried this myself a few years ago.............. not sure if I did it right.....

 

[bubbaG80Sport]

I tried this myself a few years ago.............. not sure if I did it right.....

View attachment 31360

You're a nut

 

[RSpectnewbie]

I looked into it when I bought my car, after overdosing on info on the 'net. Research showed that the vehicles most prone to carbon build-up on the back of the intake valves (usually cleared by detergents in the gasoline, but GDI injects right into the cylinder) were VW/Audi engines. Other GDI's were not affected as much. Some people were saying that maybe CVVT engines helped to slow the issue.
Based on my own research (which included a quote for $2500 to do the work), the fact that the engine runs just fine, and most of the info on the net I decided against it. I've recently bought an oil catch can which I will install mostly for peace of mind and to see what the results are.
If the can catches a lot of oil I'll use the cleaner before an oil change. If the engine starts to run rough and they diagnose build up then 'll use the blasting if I still plan on keeping the car at that time.
Just giving you my thoughts from my research, feel free to do your own research if you are still worried.

 

[Trixie86]

I looked into it when I bought my car, after overdosing on info on the 'net. Research showed that the vehicles most prone to carbon build-up on the back of the intake valves (usually cleared by detergents in the gasoline, but GDI injects right into the cylinder) were VW/Audi engines. Other GDI's were not affected as much. Some people were saying that maybe CVVT engines helped to slow the issue.
Based on my own research (which included a quote for $2500 to do the work), the fact that the engine runs just fine, and most of the info on the net I decided against it. I've recently bought an oil catch can which I will install mostly for peace of mind and to see what the results are.
If the can catches a lot of oil I'll use the cleaner before an oil change. If the engine starts to run rough and they diagnose build up then 'll use the blasting if I still plan on keeping the car at that time.
Just giving you my thoughts from my research, feel free to do your own research if you are still worried.

Thanks, but my car only has 1600 miles. Not sure I would attempt having twin turbos.

 

[RSpectnewbie]

In that case......the only use you have for walnuts is if you have a nut-cracker and the munchies.

I have a 2013 Rspec with the 5.0 so I had more concerns.... and no nut-cracker....

Thanks, but my car only has 1600 miles. Not sure I would attempt having twin turbos.

 

[TinsleyC]

Check out post #23 in this thread -

Excessive intake valve buildup

 

[snipes81]

Coincidentally, I ran a can of GRC intake cleaner through my 2018 G80 Sport 3.3T this weekend. Doing this regularly and having a oil catch can installed on PVC side of intake manifold I'm hoping to eliminate the need for walnut blasting down the road.

What are your thoughts on the oil catch can impacting the car warranty?

 

[pulsar]

What are your thoughts on the oil catch can impacting the car warranty?

Catch cans don’t alter the performance so dealer would have a hard time denying a warranty claim unless they could show the CC affected something. Every dealer is different though and this question has been asked many times so installing an aftermarket part is not risk free. My opinion is it’s very low risk. I have one and if I need to take my car in I’ll leave it installed.

 

[bubbaG80Sport]

What are your thoughts on the oil catch can impacting the car warranty?

I don't think it will have an impact on car warranty, but it will vary from dealer to dealer. If dealer or HMA does not want to do the warranty work they could use the OCC as an excuse. I mounted my OCC so it is easily removable and can return back to "as delivered by factory" in about 5 minutes. I remove my OCC before taking it in for service/repair to avoid any debate over warranty work.

Details on my 2018 G80 Sport 3.3T OCC setup can be found here.

 

[Bill in Alexandria]

BG has a product that's blasted into the intake vacuum hose. I think they shut the engine down and let it soak and then start her back up and spray some more. Obviously doesn't require pulling the valve cover, etc.

BG Air Intake & Valve Cleaner – BG Products, Inc.

Sprayed directly into the intake, it restores fuel efficiency and engine performance and reduces harmful exhaust emissions.

www.bgprod.com

Here's a vid of before and after BG service:

Hope this helps!

 

[snipes81]

I don't think it will have an impact on car warranty, but it will vary from dealer to dealer. If dealer or HMA does not want to do the warranty work they could use the OCC as an excuse. I mounted my OCC so it is easily removable and can return back to "as delivered by factory" in about 5 minutes. I remove my OCC before taking it in for service/repair to avoid any debate over warranty work.

Details on my 2018 G80 Sport 3.3T OCC setup can be found here.

Thank you for the response and the OCC setup link. You didn't happen to do one for the GRC intake cleaner as well by chance? I checked the manufacturer website and their procedure looks a bit involved for someone who hasn't wrenched much on cars since high school.

 

[bubbaG80Sport]

You didn't happen to do one for the GRC intake cleaner as well by chance? I checked the manufacturer website and their procedure looks a bit involved for someone who hasn't wrenched much on cars since high school.

No I had not posted details on using the GRC intake cleaner. I'll summarize here. I followed the instructions on the can exactly except where it was sprayed.

Safety precautions
S1) Park/run car in a well ventilated area. I left my girls "arse" hanging 4 feet out of the garage.
S2) I was very concerned about spraying this on the Mass AirFlow Sensor (damage it or throw a code). Instructions indicate NOT to get this on the MAS.
S3) Use a rag where the GRC nozzles goes into this metal pipe to avoid spraying/spilling GRC on engine. GRC is Polyether Amine (PEA) designed to break down carbon. Probably not good to get on metal, plastic and hoses under the hood.
S4) Wear chemical resistant gloves (disposable Nitrile, etc.), eye protection and keep mouth closed. Using a spray can it is common to spray it in places you shouldn't. It got some in my mouth and PEA tastes like gin. Fortunately no hair loss or growing a 3rd nipple as of today .

1) Get a can of GRC intake cleaner (duh!).
2) Warm up car to normal operating temperature.
3) I disconnected a rubber hose coming off the driver side air filter/box. This hose goes into a fixed metal pipe that runs from top/front of engine into the manifold at the rear end/firewall side of the intake manifold. GRC was sprayed into this metal pipe.
4) Having a 2nd person to operate "go pedal" would makes this job easier. There is no throttle cable/body lever under hood to operate throttle (electronically controlled). I was able to tie a string to the gas pedal and operate it from under the hood. It is very difficult to maintain 2000RPM per instructions. Car wants to keep reving up. I rev'ed engine up and down spraying GRC on the up revs, but keeping below 3K RPMs.
5) I was able to spray about 3 seconds at a time. Engine will stall if you spray continuously. As RPMs drop stop spraying. It took about 30 minutes to empty the spray can. Instructions say to keep GRC spray can up or down, but not to tilt sideways. I sprayed with can upside down/inverted.

I did NOT notice any noticeable change in the exhaust fume color while injecting the GRC. There was no additional carbon buildup on the exhaust tips.

Subsequent to running the GRC through the engine it's hard to tell if it made any difference. It "seems" to run a little smoother, but car was running fine before and it could just be a "placebo effect". Regardless, I plan to do this every 10K miles as a preventative measure.

No ECU/OBD codes were thrown/caused. At next fill-up case mileage was about +1MPG. This surprised me as I expected reving the engine standing still for 30 minutes would have caused MPG to go down a little. I'll continue to check MPG in the future.

Take your time, be careful working under hood with engine running and you'll be fine (that rhymes) .

 

[TinsleyC]

Thanks for the instructions.. and humor!

If you have time, maybe post a photo of the exact pipe and entrance to said pipe where you spayed the stuff in?

Do you plan to change the oil afterward? Seems like it wouldn't be good to have traces of stuff like that in the oil.

 

[bubbaG80Sport]

I'll put taking a picture on my to do list. In the interim the rubber hose off the air box is the "Hose Assy-Breather", part code 26710 here.

I did not change the oil afterward, because. I don't think it is warranted after GRC/PEA service. The only way the GRC/PEA could get into the oil system is by the piston rings. Wash down was a common problem on carburated engines with high miles+worn piston rings of which my Genny is neither.

I typically do an oil analysis (Blackstone Laboratories) at each 5K mile oil change. I'll be watchful for any anomalies in my next oil change report.