The Intake Manifold: Clean and Shine

Intake manifold still in the car (Volvo P1800E 1970).

Below are photos before removal of the attachments and cleaning (Click for full size photos).

Intake before the bulk of the repolishing, but after loosing polish in the wheel cleaner mishap ( see text below).

A manifold of issues cleaning the manifold. After stripping the intake of all the hose fittings, throttle plate, TPS, and cold start injector, the first cleaning attempt involved hot water, Simple Green and a scrub brush. The Simple Green removed a good portion of the grime, but things were still looking grim. Next in the arsenal came a spray can of a carb cleaner. Carb cleaner helped in a few spots, but still not great. I should have tried paint thinner, one of my new favorite part cleaning fluids...... next time. Lots of Googling suggested that aluminum wheel cleaner (the kind for wheels without a clear coating) was the thing to use. Well, it did a great job getting the rest of the gunk off, and with the gunk, the original shine/polish. I assume this was an acidic cleaner that etched the surface? Now, had a nice clean manifold that looked terrible. Had this been a relatively smooth casting, loosing the original polish would not have been a big deal because it would be trivial renew with metal polish. The rough "sand cast" surface creates problems for the metal polish. To avoid all these pitfalls, it seems as if most people decide to media blast and then followup  with a clear or metallic powder coat or paint. Other options seem to be grind off all the casting marks and surface irregularities to create a smooth surface that can be easily polished. The manifold is rough cast and it seems that most of the advice on the "interwebs" is geared toward manifolds that are inherently smoother. I had a hard time finding useful information on how to approach such a rough surface.

 I'm still weary of painting things and try to avoid it if possible.  I see paint as something that can scratch, peel, chip, discolor and always need to be repainted, therefore "natural" surfaces would seem the most durable and easy to maintain. Clearly, lots of people with MUCH more experience than I have in these matters paint these things, they must be on to something. The paint looks good and may even aid in cleaning by creating a smoother surface that oil and grease can be wiped off.

I decided I would try to polish my now clean and dull manifold although after the cleaning described above, maybe I should have just painted it. Live and learn.  Just taking polish to the surface only shined the high parts, simultaneously filling the voids with black residue, not so good. A carbon steel wire brush on a Dremel seemed to do a good job, but I was worried that I might be causing the aluminum  on high parts to actually smear over the pores, possibly entrapping stuff in the pores of rough cast surface.  As I used the wheel I noticed the apparent porosity of the surface diminishing, without the apparent removal of material. The dremel did help clean up hard to reach areas, but mostly I went after/over the whole thing first with a rough and then a smooth Scotch Bright pad, followed by metal polish and a few rounds of scrubbing out the reside with a toothbrush and dish soap. Actually, the dish soap was not so good at removing the residue from the Mothers polish; Mr. Clean worked better.

Here is the finished version, before replacing all the fittings.

The manifold certainly looks much better than when when the process started. If I were starting again, I would try using Never Dull wadding polish after the Simple Green. The Never Dull did not produce a great shine (Mothers did that),  the solvents it contained were effective at cleaning the surface and it certainly would not have damaged the surface like the wheel cleaner. I wonder if Mothers polish contains more fine abrasives than the Never Dull.  The final result is not perfect, but certainly a step in the right direction. I can always work on it latter, right now there are bigger fish to fry, like all the other parts and the seized engine....

Bosch Coil

In the car...

Out of the car before cleaning and painting:

Note: my hands would not be so dirty, those must be my Wife's...

The coil was painted with POR-15; I've been having issues with air bubbles in the paint as you can see... although the lighting in this photo makes them a little more noticeable than I think they will be in the car... (and I'm sticking to that). At any rate, it looks much better then it did, I could wet sand and spray it, but I do like the fact the POR is so durable; also, I can't spend my whole life working on one part... so, time to move on. The bracket was originally galvanized; I sanded it down to remove rust, applied Napa self-etching primer and then Rustoleum "Bright Coat" "Metallic Finish" "7714 Aluminum".  I'm trying to list all the paints used so that when/if things fail I will know what works and what doesn't. Testing with an Ohm meter showed that the primary and secondary coil were within in specifications so it should be OK.

The South end, with part number (0 221 102 0) 12V

Fuel Pressure Regulator

Before..

Here is the Bosch fuel pressure regulator in the car, it's held in place by a nut that attached to a bracket on the heater/blower box.

The Bosch fuel pressure regulator  (stamped 0 280 160 001,  below the part number are the numbers  123) was cleaned up using a wire brush on a Dremel tool, and lots of metal polish (Mothers). The bracket was cleaned up and painted with POR-15 gloss black (available here); more air bubbles remained in the paint that I would have liked, but I will wait to repaint it once I know how I will paint the heater box, to which the bracket attaches. The new regulators I've seen on the web look to be cadmium plated. Clearly I would have polished some of that off, but there was no evidence of it, even on the hose barbs that would have been covered.....? Testing of the pressure regulator will have to wait until more of the fuel system is up and running.

Manifold Pressure Sensor

Bosch Manifold Pressure Sensor






















After cleaning

I cleaned it up using a brass brush on a Dremel tool followed by Mothers Mag Polish. The base was cleaned up and painted with black POR-15. It could use more polishing, but at this point I'm not sure if it works, more on that below..

I assume this is the original part.... but, it does have a VW logo and part number (311 906 051 B), in-addition to the Bosch part number (0 280 100 001). I tested it to see if it would hold a vacuum, it did, but only for about 30 seconds. I'm still reading up on how the part works, but it does seem that there is supposed to be a epoxy plug on the adjustment screw (not sure if this is to seal the unit or just keep the adjustment screw in place). Some epoxy (amber colored, lower right in photo above) seems to remain at the base of the screw housing, also the screw was covered with a blob of black putty which I'm sure was not air tight... not sure if that was original. So more testing and reading is needed on this part...

Edit: Got an email from Brad Anders who points out that "The 001 MPS is for the Type 3 VW's (e.g. Squarebacks)" Other responses suggest that this part was likely replaced and would not have appeared on a P1800. Thanks for all the responses! I guess this is one more thing to deal with when the car gets closer to being done, which is still a fews years off....

Coolant overflow bottle bracket (take 2)

This is the bracket that hold the bottle for the coolant overflow in the car.

I think the part was galvanized.... so I thought I would try Rustoleum's "Cold Galvanizing Compound". Well it looked really good!

Until you touched it, OK dragged a fingernail across it, the "paint" does not stick even after the metal had been etched! Well some web searches turned up that this is what it does, its not really a paint, but a "compound".... Not sure what it's good for, but it's not good for car parts.... So, the part sat around for a long time because it was depressing to look at it and think of all the wasted time. Finally after the old "paint" was  taken off using lots of paint stripper and a metal brush, I coated it with NAPA self-etching primer and Rustoleum Bright Coat "Metallic Finish" "7715 Aluminum". Looks good and should be more durable.

Windshield washer bottle and holder.

Here is the very rusted windshield washer bottle and holder in the car.

All painted. At some point I will look for a new holder, this one is in rough shape... degreased, POR Metal Ready, and POR-15 black semigloss. This should keep it from rusting for awhile, the sun in the photo really catches the rust pitting, in the car, I don't think it will look so bad. I did not test the motor which sits in the bottle, I figure it's easy to get to and is the least of my issues at this time.

Throttle Position Sensor

Removed the Throttle Position Sensor (TPS) cleaned the inside up a bit and painted the metal and screws.

On the intake manifold...

Opened up. I'm not sure if that is the remains of dirt or an old gasket along the edges of the metal backing plate. I think it was an oil and dirt mix that creeped in over time; there are two notches on the left side of the metal plate which would prevent a seal anyway, so a gasket would seem not to make sense.

Cleaned and painted, I used the NAPA self etching primer over that just some silver colored spray paint. I think I will replace the two mounting screws seen on the upper right of the photo....