BRM Intake Manifold Clogged with Gunk

[relumalutan]

Good job on the bracket JETaah. Maybe you can give us some details so I can make one for my car. I remember when you've fixed my failing hood insulation using welding wire. Simple but ingenious!

 

[bherman13]

Everything wears out. PD is a wear engine on everything - be it cams, egr coolers, DMFs, injectors, cylinder heads or even intercooler hose clips and hoses themselves.

At that mileage you might have wear on injector bores on the cyl head. Worth checking.
Injectors typically last a bit longer but it's not uncommon to see a work injector or two at that miles also.

I'm not familiar with this problem. How does one go about checking this?

 

[Henrick]

If you don't have fuel to oil dillution, don't get in there.
The injectors are fixed on one side, using one bolt. They rock back and forth once being pressed down in their bore.
Over time and miles, the bores wear out. Visual inspection shows sharp and/or worn edges.
As a remedy for that, these bores can be sleeved. I have seen a few cylinder heads with sleeved bores. However, I didn't find any shop locally which would be offering such service. But hey, I don't own a PD and I don't have such a problem...

 

[bherman13]

Does the fuel get in the oil with that problem? Or does the oil get in the fuel?

 

[Henrick]

Fuel gets into oil.
Depending on the wear, oil level rises.
Worst what I have seen is about 3 inches over the MAX mark in a few days.

 

[bherman13]

Wow that's some pretty bad oil dilution.

Fortunately, mine's at least minor if not non-existent. The oil level has never risen noticeably.

 

[sptsailing]

OK, so I took mine apart and it looks a lot like his too. So I know I have been running for quite a while with the #3 exhaust cam pretty much destroyed, plus, my EGR cooler has been leaking exhaust at the flap valve for years and I think the turbo bleeds too much oil into the intake side. At least that is what I think might be the source of this mess.

 

[sptsailing]

So after watching several youtube videos and reading a variety of posts about how to clean my intake manifold, I decided to use "Heat 'n Kleen Gold Medal 31 oz Popcorn Machine Kettle Cleaner", which I bought on EBay. I have a college degree in chemistry, but I have no lab to figure out what is in this proprietary product. It seems to be working work great, as it takes the goo off completely, some parts without any scrubbing at all. The intake manifold fits perfectly inside a large roasting pan, which I set outside to cook on a 2 burner electric stove. This product appears to work by slowly dissolving whatever the oil polymerization product is that is binding the soot into a gooey mess. It is taking awhile and does not damage the aluminum at all.

I had thought about using the torch method, but my wife asked me not to as it might scare the neighbors or cause the fire department to show up.

 

[invader]

get an egr delete tune from Mark, it costs $99

the intake will never clog again

http://www.malonetuning.com/pd-tdi

BINGO!! EGR delete. I have one and I don't have this problem. And I don't care what anyone says about this being normal or OK. I don't want a bunch of build up like that in my intake.

 

[sptsailing]

I am still trying to clean the gunk out of my intake ports without having to take the cylinder head off of the car, and researching it extensively, I discovered what appears to be a clever way to do this by shot blasting with walnut shells. Search Youtube for BMW, Walnut Shells and Intake Ports and you can see how others have done this.

Of all places, Harbor Freight sells the walnut shells and a couple variations of appropriate shot blasting equipment. I would just need to fabricate some sort of fitting for the ports similar to the one the BMW folks use.

I solicit comments as to the suitability of this solution, as I may be overlooking some reason it could not work for a VW BRM.

 

[sptsailing]

The walnut shell blasting solution I found on https://www.youtube.com/watch?v=NnMhNXXawjk appeared to me to be the best way to clean the intake ports in the cylinder head, but in order to test this, I decided to try it on something other than my car. http://www.cylinder-heads.com/ was near to my location, and I was able to buy a bad BRM cylinder head that had similar carbon intake port buildup to experiment with.

After experimenting quite a bit with a process similar to what the BMW Youtube video showed, I have concluded that this method is indeed very useful. This has been an iterative process, and I believe that I have finally arrived at a final, workable iteration.

I am curious whether or not anyone else here has already used walnut shell blasting to clean VW TDI cylinder head intake manifold ports, or, discovered definitive reasons why this method should not be used.

 

[relumalutan]

The walnut shell blasting solution I found on https://www.youtube.com/watch?v=NnMhNXXawjk appeared to me to be the best way to clean the intake ports in the cylinder head, but in order to test this, I decided to try it on something other than my car. http://www.cylinder-heads.com/ was near to my location, and I was able to buy a bad BRM cylinder head that had similar carbon intake port buildup to experiment with.

After experimenting quite a bit with a process similar to what the BMW Youtube video showed, I have concluded that this method is indeed very useful. This has been an iterative process, and I believe that I have finally arrived at a final, workable iteration.

I am curious whether or not anyone else here has already used walnut shell blasting to clean VW TDI cylinder head intake manifold ports, or, discovered definitive reasons why this method should not be used.

I was considering the same process for my BRM, I even watched the same video you are referring to 3 months ago. I have a Harbor Freight close to me and they have the walnut blaster available. My only concern was how to make it work, since there is almost no access room behind the engine.

 

[sptsailing]

First off, you have to remove the starboard drive axle, which I did. Then, I have followed Oilhammer's advice to remove the subframe to make all access much easier. This made removing the downtube, EGR cooler, and turbo much easier. All of these things create sufficient maneuvering room, although nothing like the unlimited room the BMW owners have.

I bought on craigslist a used 40 lb. device, identical to the BMW video. I have experimentally determined that 1/4" O.D. copper tubing is the minimum size that works with Harbor Freight fine grade walnut shells. Setting the Harbor Freight tank's pressure to 80 lbs. and not opening the bottom media feed valve more that the minimum to get a sufficient, but not over supply of walnut shells works perfectly, quickly removing ALL the gunk and leaving the bare metal showing. There are apparently some walnut shell fines left visible in the joint between the valve and the seat, but I believe a pick can take all of the significant ones out with no problem. I have not yet figured out how to remove the valves in the experimental head so as to be able to determine the actual extent of the gunk removal, but will try to do so over the next few days.

I am doing this planning on having the shop vac and fitting from the bottom, and maneuvering the abrasive blaster from the top, after first insuring that all fluid port openings are protected from dust intrusion.

Franko6 advised me to simply use a torch to burn these ports out. Although I am certain this would work, based on experimenting with my test head, my painful experiences with several house fire events prevents me from being able to manage to do this on the engine still in my car.

Now in my case, I have already removed the CAM for replacement, which means all the valves are definitively closed. Theoretically, this could also be done on any BRM by removing only all the components attached to the stern side of the engine and working on cylinders having both valves closed by adjusting the crankshaft position.

I will be keeping the group posted on my progress. It is heartening to know others are considering this approach.

 

[sptsailing]

Walnut shell abrasive blasting appears to work very well

I was able to get the valves out of the experimental cylinder head by using a 1" Deep Socket in which I had placed, recessed down about 1/4" on opposing corners two 14mm X 5 mm N50 Super Strong Neodymium Round Disc Magnets. Pushing this down exposes the keepers to the magnets at which point they immediately fly off.

Examining the results of the walnut blasting on the experimental cylinder head confirmed my suspicion that those portions of both the port and the valve stem that are not visible have to be considered carefully in order to create and use a shaped 1/4" copper tubing nozzle that can expose those surfaces sufficiently to the force.

I shaped what I thought would work, examining and practicing how I would use it on my actual engine's ports. Once this was done, I rigged a board across my engine compartment on which I could lay and work on the ports from above.

So I finally figured out a way to have successfully walnut shell blasted all 4 cylinder head intake ports on my BRM. The process took everything out down to the base metal and everything I can observe in each port looks like new. Lacking tiny mirrors or a borescope, it is possible there may still be something stuck in there that I cannot see, but the process appears to have worked extremely well.

I will not be able to fully claim success though until I have everything assembled and the engine running, hopefully, later this week. I took some cell phone photos, but I have to get this car running again as soon as I can, so will post them sometime later.

 

[sptsailing]

Walnut shell blasted intake ports

 

[absalom]

Stupid question, but how do you get the walnut shells back out of there? Looking forward to updates on this.

 

[sptsailing]

Stupid question, but how do you get the walnut shells back out of there? Looking forward to updates on this.

The 4th picture shows a 1-1/4" PVC Schedule 40 street elbow patially reshaped with a vise after being boiled in water and by cutting off most of the smaller diameter length and, with duct tape diameter adjustment, fitted into a shop vac hose. The shop vac air volume greatly overwhelms the air volume from the compressed air carrying the walnut shells at high velocity into the port, so there is no leakage of walnut shells either during or after the blasting action is discontinued. Straight compressed air gets the last few grains out.

Since BMW officially sanctions the use of this technique, as evidenced by many youtube videos of such processes being demonstrated on BMW cars, I was slightly surprised that a procedure like this has not already appeared somewhere in this forum for use on VW diesels.

Thinking about it further though, it is much more difficult on a BRM than on the engines shown in the BMW walnut blasting videos, as on a BRM, the EGR cooler, the turbo and the exhaust manifold need to come off, and that is a non-trivial exercise. The primary utility would be for someone who already needs to have the turbo off, as they could just remove the intake and clean it as well while they had the turbo out of the way.

 

[absalom]

Did you notice a difference?

 

[sptsailing]

Not yet. Everything I do takes too long, and refurbishing the front end of my PD TDI is no exception. She's back on all fours finally and I expect to be able to run the initial cam break in procedure tomorrow. It will be awhile before I will be able to tell much, assuming I did not forget some important thing and as a consequence, trash the engine.

 

[sptsailing]

My TDI is finally running again, and performance is excellent. No smoke, excellent power and response, no CEL codes, no problems. It is SO GOOD to have this car back in service and running well. However, since the work on this engine included both replacing the cam and totally cleaning the intake path, performance gains cannot be attributed to a specific change, such as having cleaned the intake path.

I will update the anticipated fuel economy improvements after a few tanks of diesel.

While dealing with this, I pondered various methods of preventing intake fouling. The most appropriate method is to make certain that everything is operating correctly. In my experience, this cannot be easily done with this car because it is structured so resiliently that it will run even with numerous issues, some of which will cause gunk buildup. So then I thought, what if the intake path was too slippery for anything to stick to? This train of thought led me to researching methods for steel and aluminum surface treatments that would simply be highly resistant to having anything stick to them in the first place. There exists such treatments available out there. I am looking into experimental methods of determining whether or not these would work.

 

[Jakeswagen]

My TDI is finally running again, and performance is excellent. No smoke, excellent power and response, no CEL codes, no problems. It is SO GOOD to have this car back in service and running well. However, since the work on this engine included both replacing the cam and totally cleaning the intake path, performance gains cannot be attributed to a specific change, such as having cleaned the intake path.

I will update the anticipated fuel economy improvements after a few tanks of diesel.

While dealing with this, I pondered various methods of preventing intake fouling. The most appropriate method is to make certain that everything is operating correctly. In my experience, this cannot be easily done with this car because it is structured so resiliently that it will run even with numerous issues, some of which will cause gunk buildup. So then I thought, what if the intake path was too slippery for anything to stick to? This train of thought led me to researching methods for steel and aluminum surface treatments that would simply be highly resistant to having anything stick to them in the first place. There exists such treatments available out there. I am looking into experimental methods of determining whether or not these would work.

Wow I've been trying to find a thread like this for months! Really enjoyed reading your investigtion and the results are clear as day from the photos. How much have your MPG figures improved since?

Also I'm interested to know if the MFD on US VW cars uses US gallons in their MPG calculation, as opposed to imperial (UK) gallons? I imagine they do but would be good to know.

I'm chasing an issue with low high-end power and low mpg on my Mk4 Golf 1.9 TDi PD 130 at the moment. The last few months I've been experimenting with the torsion setting and recording the results - I have seen an improvemen in MPG with the optimal setting however it's only very marginal (+5%). Currently I'm getting an average of 40mpg (MFD reads 42.5) which is terrible compared to what I used to get with my old Golf with the exact same engine - Same routes and driving style in that old car I was getting an average of 50mpg.

My next step is to clean the intake manifold and inlet valves - Got myself a bottle of Heat n Kleen on order for the manifold and am booking my car in for walnut shell blasting with a local specialist.

The thread I started to investigte these issues is here - http://forums.tdiclub.com/showthread.php?t=491036

I haven't updated this for a few months but am planning to do a full write-up of my torsion setting results before doing so.

Anyway man just wanted to say thank you for such a good contribution!

 

[sptsailing]

Thank you so much for the compliment. Please note that the posts of Oilhammer, Franko6 and many others have been critical to the evolution of my BRM TDI maintenance experience, and I defer to their posts in any areas where my posts might conflict with their conclusions.

Due to numerous family problems and my general disorganization, I do not have enough data points to make confident statements as to the mpg improvements, but my best observation thus far is that the current 43mpg city driving with A/C is definitely better than the mid 30's mpg prior to the cam replacement and all the other repairs I had to do.