All right, after a busy week, I finally have a bit of time to update this thread.
Last Saturday, my dad was down for Father's Day weekend and we removed the IM again to see how effective the Seafoam was at removing the carbon from my intake valves.
As I mentioned back in post #33
, I wondered if using the brake booster vacuum hose to introduce Seafoam into the IM would actually introduce it to both cylinder banks, or just primarily one side.
As you can see in the photo below, the IM is internally divided into two banks, which in turn feed the intake runners on the opposite
side of the engine:
The brake booster vacuum attachment (red arrow) comes in on the driver's side
rear of the IM, which feeds the passenger side
bank of cylinders (remember, the IM is upside-down in the pic, so things are reversed). I wondered if the internal division of the IM was continuous from where it splits near the throttle body, or if there was opportunity for the sides to "communicate" other than the very front of the IM.
So after pulling the IM, the first thing I did was turn it upside down and run my lighted borescope up each side of the IM. Running it up the passenger side showed light out each runner on the driver's side of the IM. I saw no light anywhere in the passenger side runners at all.
Next I ran it up the driver's side of the IM. When the borescope got right next to the brake booster vacuum connection, there was some very
faint light visible in the rear runner opening on the driver's side (which is fed by the passenger side of the IM, remember?). As soon as the scope was moved slightly
away from the vacuum connection, the light disappeared.
So it appears that there may be a small communication between the two halves of the IM near the vacuum attachment. I am not sure how much Seafoam would make it to the driver's side bank of cylinders via this communication; it seems to be very very small based on the amount of light that passed and how any small movement of the scope would make the passed light disappear from the other side.
In my opinion, to ensure a good Seafoam treatment on the LFX, you should not rely solely on the brake booster vacuum attachment. You should definitely use the Seafoam spray from the throttle body side of the manifold to ensure treatment of both cylinder banks, either in addition to the brake booster vacuum line or instead of it.
OK, on to the evaluation of the effectiveness of the treatment.
First thing I noticed was that the inside of the IM was coated with a clear, oily substance. I believe this was residual Seafoam and not PCV-related oil ingestion, as the appearance of the substance was clear and not oil-colored at all. I'm not thrilled about this coating after cleaning the IM previously with intake cleaner--which left no residue--but it's unavoidable.
I also found the same substance where the IM gasket meets the metal intake runners on the head:
Note in the close up the barely visible ring of clear fluid around each opening. Compare this to the pics of the same area I posted in the first post in this thread, and you'll see why I'm convinced this was Seafoam and not PCV products. Later in this thread I'll show what I drained from my catch can when I did my post-Seafoam oil change, and you'll see it's far from clear.
All right, on to the appearance of the valves themselves:
So, the Seafoam helped remove the big chunk of carbon off of the one valve, but still left a lot of residue on each valve trumpet and a "collar" of deposits on each valve stem. Not as clean as I had hoped.
While we had the IM off and the valves accessible, we decided to manually clean them. Again, we referred to intensifi's guide
, although we sort of modified the technique a bit.
I purchased a gun cleaning kit at Walmart for about $20:
The various diameter brushes and extension handles worked well for accessing the valves down through the runners. I was able to bend the brushes into an "L" shape to get the rear of the valve stem and the back of the valve trumpet. The bristles bent/deformed easily, though, and I went through several of them during this procedure.
Another note about using the brushes: as they began to wear, I found an occasional stray bristle laying on the valve after cleaning. I was able to suck them out using the shop vac, which I will describe later. Just be aware and look for them if you use this procedure.
For a cleaning chemical I used my remaining Seafoam spray. I had purchased some intake/carb cleaner for this purpose, but after talking with my dad decided to use the Seafoam instead. The concern was that the stronger cleaner would potentially wash the cylinder walls and leave them dry at the next startup. The Seafoam has some lubricity, so even if it washed the cylinder walls there would be some level of lubrication remaining.
First, I sprayed a small amount of Seafoam into each runner that looked like it might be closed. If the fluid pooled and remained, the valves were closed and those were the areas we cleaned first:
In the pic above, the left valve shows how the Seafoam looked when sprayed onto the valve. It has a blue appearance. The right valve has been scrubbed on a bit, turning the seafoam gray. Eventually it would turn dark gray to black as the deposits were removed.
We had 4 of the 6 sets of intake valves closed initially, so we cleaned those first. The cleaning procedure consisted of:
- Spraying Seafoam in and letting them soak for 10-15 minutes
- Scrubbing with the wire brushes
- Stuffing a narrow strip of T-shirt cotton rag into each runner, wrapping it around the valve stem and using it to help scrub the valves and soak up the majority of the Seafoam gunk
- Using my shop-vac with an adapter and a length of 1/2" diameter plastic tubing to vacuum any remaining Seafoam and as much debris from around each valve as possible
This is us using the brushes to clean the valves:
Holding a flashlight in one hand and scrubbing with the other worked well, but by the end the hand holding the narrow brush handle was pretty fatigued.
I don't have any shots of using the rags, but I can tell you that narrow strips worked much better than larger pieces. It was easier to stuff them around the back of the valve stem and work them back and forth. They came out dripping with black gunk, so be prepared.
Next we used the shop vac adapter and with masking tape attached about a 2 foot length of 1/2" diameter tubing:
We could then insert the tubing down near the valve stem to suck up any remaining Seafoam, debris, or the occasional brush bristle from the valves.
After we did the initial 4 sets of valves, we used a 19mm socket and a breaker bar to rotate the crankshaft bolt by hand and close the remaining two sets of valves. We did not remove the spark plugs to release the compression, and while it was stiff to turn, it wasn't horrible.
One of us turned the crank while the other watched the open valves slowly close. At some point, the valve would seem to stop moving, even with further crank turning, and that's when we would test them for Seafoam pooling.
After all the valves were cleaned, here's what they looked like:
For some reason I only took 5 pics, but essentially they all looked similar.
A couple of notes about this technique:
- I was unable to get all the loosened carbon deposits either soaked up with the rags or vacuumed out. The loosened deposits settled around the perimeter of the valves and I couldn't extract them. They're particularly noticeable in the picture showing the valve after it was cleaned and then opened. I am hopeful that this debris was just kind of loosely wet-caked on these areas and that as soon as the engine was run that they were sucked into the chamber and burned.
- There was a hard "collar" of deposits on the valve stem that proved very stubborn to remove. I was unable to completely remove the collar from several of the valves despite prolonged scrubbing and repeated wetting with the Seafoam. However, I think I greatly reduced the size of the collar in all cases. Perhaps a stronger cleaner would have done a better job of softening/removing the collar.
After the cleaning was all done, I changed the oil/filter and drained the catch can. This is what my RX catch can collected in a little over 2,000 miles:
As you can see, it's definitely not the same stuff I found in the IM or around the port openings. Yuck. After I emptied it, I removed the hose from the center (input) fitting on the can and we carefully/slowly sprayed some intake/carb cleaner down into the can and out the open drain valve to flush the can and drain hose. (The pic above shows only what the can collected, not any additional liquid from flushing the can/hose.)
OK...there you have it, folks. My car ran ~28,000 miles without a catch can. You saw the resulting deposits, the effects of a Seafoam treatment on them, and how I manually cleaned them.
Hopefully my catch can will prevent any further deposits from forming. Perhaps in the future I will pull the IM again and check.
Thanks for reading!