Carbon cleaning (small?) - spraying intake manifold (documentation)

[ven0m]

Hey guys, it was 10k km after my first carbon clean last year (previous clean) and I decided to do a small touch-up clean with Wynn's Carburettor Cleaner.
The spray was inserted at the back of the intake manifold where we have a small plug. Wynn's spray cans are good as they have very high pressure.



1st) The car was warmed up to 90°C oil-temp
2nd) I started spraying the IM in small pulses while a friend was holding the RPM above 2500
3rd) I stopped at 1/2 spray-can and let the car settle and rpm to stabilise for a bit
4th) Sprayed the other 1/2 into the IM in small short pulses, followed by a short red-line
5th) Car idled like a baby



The car smoked like hell during the rev-battle with the cleaner, but the end result was surprising. I won't say there was a power increase because I didn't notice it, but the way the engine was acting was surprising. It was calmer, smoother, throttle response was faster (a lot faster), more subtle, more direct, there was less exhaust burble - WHICH I DIDN'T LIKE to be honest.

I will be doing a normal carbon clean with walnut blasting next year again (after 10k km) and I was willing to do a small experiment as the community helped me a lot. (I'm also changing injectors, pcv, etc.)
Should I:
a) Do another smaller clean with the carburettor cleaner just before I take off the IM?
b) Don't do a small clean and see how much carbon will be on the valves 1 year after THIS small clean?

[NYC_Legacy]

I am tempted to do this myself. Thanks for the write-up and informative pictures.

[iduff]

I vote for a repeat of this treatment before you do the media blast carbon clean next year.

Folklore has it that a carbon clean can last as few as 5K miles, so if you repeat this just prior to your full-on media blast carbon clean next year, you'll be able to see how effective it is. And report back to us slavering masses.

[Reggie]

I would support doing a spray before the carbon clean with lots of pictures

[FaisalJ]

What would be fantastic would be to log max MAF airflow before and after the clean - that'd be a sure fire way to quantify any improvement.


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[ven0m]

Thanks for the feedback guys!

What would be fantastic would be to log max MAF airflow before and after the clean - that'd be a sure fire way to quantify any improvement.


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I have a local tuner near me, where I already did dyno measurements last year; but only after the carbon clean, so I didn't have any baseline for comparison - just my own feeling and boy did the car pull much harder + kicked at 6krpm and just shot to 8k
This time I'll try to get measurements on the dyno and with my dongle (Fuel trim, MAF, etc.) before & after to have a baseline comparison.



It sucks that the tuner went on vacation last year and we couldn't get a baseline, as it was the first clean for the car @110k km.

[Fourplay]

What you really need is a borescope so you can do a before/after down the spark plug holes. Remove the plugs and go from cylinder to cylinder until you find one that is open. Take photos and see if this procedure actually does anything.

[Jake@JHM]

This is easier than walnut blasting: https://jhmotorsports.com/shop/catal...+clean&x=0&y=0

[ven0m]

What you really need is a borescope so you can do a before/after down the spark plug holes. Remove the plugs and go from cylinder to cylinder until you find one that is open. Take photos and see if this procedure actually does anything.

Why would I need a borescope if I'm going to take the manifold off?

[Fourplay]

Why would I need a borescope if I'm going to take the manifold off?

Because having a before/after photo comparison of the intake valves is absolutely critical to determine whether or not your procedure is effective.

If you do choice A in your poll, there is no way to know whether or not the 2 sprays of carb cleaner helped at all, because your only photo points of reference are: 0km after carbon clean (totally cleaned valves), and 20,000km after carbon clean (dirty valves). If you do choice B, the same is true.

You need a pre-treatment photo and a post-treatment photo to empirically prove that this carb cleaner treatment works. Hence the borescope suggestion.

I might actually try it myself. Just need to pick up a borescope.

[ven0m]

If you do choice A in your poll, there is no way to know whether or not the 2 sprays of carb cleaner helped at all

Now I understand what you meant, don't take me the wrong way, I like your input.
If we look at the possibilities AFTER the 2nd spray (without doing a borescope prior):


Possibility #1: Valves are dirty.
Result: Product is useless.


Possibility #2: Valves are clean. => 2 Possibilities
Possibility #2a: Valves were cleaned-good at the first intermittent spray and current spray.
Possibility #2b: Valves were cleaned at the second (current) intermittent spray.

Result: From both possibility 2a & 2b you can assume the product works and helps with intermittent cleaning.
I'm not trying to prove it's a replacement, I'm trying to see if it's a "band-aid" for the carbon.

Due to this, I don't see a reason of checking the valves prior to spraying and taking off the IM.
Please correct me if my logic is wrong in this, I won't take it the wrong way.


Ps: this whole possibility thing makes me feel like Schroedinger and the carbon is my cat... I feel like back at school studying quantum mechanics.

[Fourplay]

Possibility #1: Valves are dirty.
Result: Product is useless.

Agree.

Possibility #2: Valves are clean. => 2 Possibilities
Possibility #2a: Valves were cleaned-good at the first intermittent spray and current spray.
Possibility #2b: Valves were cleaned at the second (current) intermittent spray.

Possibility #2c (unlikely): Engine has only run 20,000km and valves aren't dirty (very rare to have no build-up, but there are reports of it).

Possibility #3: Valves aren't extremely dirty, but aren't completely clean either (somewhere between the top and bottom images below)
In this scenario, it's hard to tell if the cleaner worked, or if the interval between walnut blastings was too short for a large amount of build-up to occur.



I've gone ahead and ordered a borescope from Amazon, so will be trying this out when it arrives next week. I'll post the results in this thread. I don't
think we have Wynn's here, so I may use a different brand of carb cleaner. Will try to compare the MSDS to get something similar.

[ven0m]

You're correct and Possibility #3 would make all results and assumptions null. As if Schroedinger cat was still in the box; dead and alive.

I have 2 different USB borescopes from ebay for 5$ a piece. They produce amazingly sharp images (1920x1080 res, for THAT price) with full LED lighting at the front and they are only 5mm in diamater with a 5m cable. You can connect them to your phone or PC. Now I remember that I wanted to check compression and wall-scorching at the same time, so I'll do the check before the spray and also scope the valves!


This is turning out to be a real investigation. If we actually manage to produce a result, a lot of Carbon cleaning shops will hate us for it.
After I did my first clean, I noticed that locally a few car-performance shops completely broke-off contact with me... Even though I never asked anything from them.

[FaisalJ]

Great if you can get boroscope images, but may end up inconclusive (I doubt the valves are going to go from coked up to nice and shiny).

3 pulls in 2nd gear to redline, record Max MAF reading.

Then do the clean.

Then take MAF readings again.

Job done.

By the way, here are my efforts to try and test hydrogen cleaning...(it does f-all).

https://youtu.be/4cHXqQywjFY


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[Fourplay]

You're correct and Possibility #3 would make all results and assumptions null. As if Schroedinger cat was still in the box; dead and alive.

I have 2 different USB borescopes from ebay for 5$ a piece. They produce amazingly sharp images (1920x1080 res, for THAT price) with full LED lighting at the front and they are only 5mm in diamater with a 5m cable. You can connect them to your phone or PC. Now I remember that I wanted to check compression and wall-scorching at the same time, so I'll do the check before the spray and also scope the valves!


This is turning out to be a real investigation. If we actually manage to produce a result, a lot of Carbon cleaning shops will hate us for it.
After I did my first clean, I noticed that locally a few car-performance shops completely broke-off contact with me... Even though I never asked anything from them.

Some of the before/after videos from BG and other manufacturers of intake cleaners are pretty impressive. It doesn't get all of the carbon but certainly seems to help. It would be great if a $10 can of carb cleaner every few months could push out the carbon cleaning intervals to 50k miles or more. Excited to see your (and my) results.

[pule333]

Video still not working on the phone :(

[jstahmann]

The port you're spraying into was named the "Vijay Port" after one of the original RS4 owners over at QW who first tried what you're doing many years ago. It's actually a vacuum port that they ended up removing from later manifolds the RS4 production run since it didn't produce enough vacuum for its intended use (brake booster).

Several others have tried what you're trying, using various cleaners (Seafoam, BG, GM TEC, etc) and for the most part you can't get enough material into the manifold in an even enough fashion to benefit all of the cylinders. Often times the cylinder closest to the port will be quite clean while the rest will still have buildup.

I have 57k miles on my 2008 RS4, and have had 3 carbon cleanings done. Since my car is a 2008 my intake manifold didn't have the Vijay port - I believe they revised the manifold in late 2007. I had the opportunity in 2010 to buy a BG Air Intake Apparatus (the one they show in the BG videos) and tried various fluids in it to see if I could replicate the amazing cleaning they show in the videos. I tried the BG Intake Cleaner, Seafoam, and finally GM Top Engine Cleaner. While none of the fluids caused the intakes and valves to be sparkling clean (I tried the different fluids and checked after each), what it did do was help keep the carbon buildup much softer, so it was much easier to clean. I've been doing the BG service using GM TEC fluid on my RS4 every 2500 miles in my garage and when I lremoved my manifold to put on my SilverRS4 Ported and Polished manifold after several of my treatments we still needed to scrape off the soft carbon. There seemed to be less of it, and it was softer, but it was still there. Later when I added my manifold spacers, we discovered the same thing - some carbon was there, but it was soft and easily removed.

I'm not trying to discount your discovery, just giving you some background on what many of us original owners have experienced as we've tried these same approaches.

[ven0m]

jstahmann thank you for the input. I read your comment already a while back, but forgot to reply.

Some valuable feedback and thanks for sharing. I chuckled a bit regarding the name of the port.