Is the 603 engine's intake manifold painted? - Page 2 - PeachParts Mercedes-Benz Forum

Jeremy5848 · #16 07-14-2008, 10:48 PM

Quote:

Originally Posted by sixto

. . . Can they do the eposed surfaces of the head? And front cover? And IP case? And engine mount arms... And...

Sixto
87 300D

Yes, if you remove them from the car and carry them in!

My plan of the moment is to do a little more hand scrubbing and then to wait 6 months or so to see if the aluminum (or whatever alloy it is) re-oxidizes. The car is 21 years old; who knows how long it took for the intake and crossover to get as bad as mine are. Maybe if I have them bead blasted and then do nothing, they will only gradually deteriorate over a period of years. If the engine was originally base untreated metal, I'd rather keep it that way.

On the other hand, if they look like s*** after six months, I'll definitely schedule the shop to anodize after bead blasting the parts.

vstech · #17 07-14-2008, 11:25 PM

odds are pretty good that manifold had some salt contact on it.
if there is no more salt spray the manifold will stay pretty clean for years and years.
still, powdercoating sure does look nice...

Marty600 · #18 07-14-2008, 11:59 PM

Warning, do not sandblast or glass bead that part, you will hate yourself for the weekend it will take to get the INTERIOR of the component, and it's oily sooty deposits it contains, to be free of the abrasives, which will stick in there worse than a magnet.
I went thru this 20 years ago on a gas engine, my son would not listen and came to my shop and glass-beaded his taurus SHO intake runners, whoa, same story.
I used silver hightemp engine paint on my benz's intake and valve cover, it still looks great 10,000 miles later. I FARMED OUT THE CLEANING JOB, and you should do the same, they went into a tank that used steel balls and fluid, and some type of revovling/agitating action--I did not see it working--but it cleaned out the inside of the intake,
just wait till you see what it looks like on your car--frankly, the guys around here with 'hot tanks' would NOT place it in thier tank, it seems that diesel byproducts damage the water-based solvents in use today...BTW, I think it was painted, from the factory...at least my 300td '92 was...And 1 last note, many casting grades of aluminum do not polish out all that great..you will have to sand the intake to remove the porosity--it's gonna take many hours of work...and then the burden begins of maintaining that nice polish--show car, or driver? Powder is best, paint is pretty darn good.

Jeremy5848 · #19 07-15-2008, 02:01 AM

Thanks for the advice, Marty. I cleaned out the plumbing after the EGR valve accidentally fell off and I had to cover the holes with some metal plates (that Brian fortuitously had) to prevent leaks. When I checked last week, the insides were clean and dry. I do know that some kinds of sandblasting are not good for soft alloys like aluminum; the people I talked to today do seem to know what they're doing but I would have them try on a small part of the manifold that is out of sight, just in case. The silver paint is a possibility, let me see how the bare aluminum looks in a few months.

I do not see the intake as ever being "polished" like (for example) the valve cover. The intake and crossover are both rough-finished castings and I plan to keep them that way, just not so dirty looking.

Marty600 · #20 07-16-2008, 01:31 AM

Hmmm, never saw the inside of my EGR, but the crossover tube and intake I have, they were the 'tarry' ones, and I learned that was considered normal. Anyway, Best Wishes.

daw_two · #21 12-19-2009, 05:53 PM

I know this is an old thread......but I'm searching and wondering what's been done before me (Coda).

I cleaned the inside of her intake manifold and crossover tube. Now, I'm looking at the outside and wondering if I should polish it or what.

So, what did you ever do, Jeremy?

Jeremy5848 · #22 12-19-2009, 09:25 PM

Quote:

Originally Posted by daw_two

I know this is an old thread......but I'm searching and wondering what's been done before me (Coda).

I cleaned the inside of her intake manifold and crossover tube. Now, I'm looking at the outside and wondering if I should polish it or what.

So, what did you ever do, Jeremy?

After cleaning the inside of the intake manifold and crossover as best I could with gasoline (yes, outdoors), I dunked them in a bucket of hot soapy water and scrubbed hard with a hand-held wire brush. That took most of the "corrosion" off (I was surprised it worked so well). After that, I followed up with "Mother's Mag & Aluminum Polish" and medium-grade steel wool. It cleaned up well enough that I decided I didn't need to have them bead blasted or painted.

From time to time I do a quick polish with the manifold on the engine and a more thorough job when I remove the pipes for glow plug replacement. I have found that once you have them cleaned up, they stay pretty clean as long as you aren't leaking oil and soot all over the inside of the engine compartment. People who never clean under the hood won't do this, of course, which is how the manifold gets cruddy to begin with.

Jeremy

daw_two · #23 12-19-2009, 10:10 PM

I cleaned the inside with Gunk removal soaked for a few hours and then car wash powered it off. Touched up with some Gunk removal on the outside, old toothbrush, and paper towels. That got it pretty good.

C Sean Watts · #24 12-19-2009, 10:42 PM

Quote:

Originally Posted by daw_two

I cleaned the inside with Gunk removal soaked for a few hours and then car wash powered it off. Touched up with some Gunk removal on the outside, old toothbrush, and paper towels. That got it pretty good.

I used some 'enviro-friendly' foaming oven cleaner in mine followed by garden hose, then off to the spray off car wash. It was a sooty mess but the intake looked great.

Jeremy5848 · #25 12-19-2009, 11:10 PM

Quote:

Originally Posted by C Sean Watts

I used some 'enviro-friendly' foaming oven cleaner in mine followed by garden hose, then off to the spray off car wash. It was a sooty mess but the intake looked great.

I have heard that oven cleaners can damage aluminum but maybe the "environmentally friendly" types are OK. Glad you had good luck and it wouldn't be as big a deal on the inside anyway since no one will see it.

Renntag · #26 12-19-2009, 11:25 PM

I wouldnt spend the money for the powder coating....I would however either purchase a parts blaster or gain access to one.

Next, I would use engine enamel to beautify the parts of your choosing.

If done properly the effect will be excellent.

Best of luck.

C Sean Watts · #27 12-19-2009, 11:35 PM

Quote:

Originally Posted by Jeremy5848

I have heard that oven cleaners can damage aluminum but maybe the "environmentally friendly" types are OK. Glad you had good luck and it wouldn't be as big a deal on the inside anyway since no one will see it.

I read the labels and all the one with lye I put back (the ones to look for are 'foaming, fume free'). I think if I left it on too long it might have oxidized but if you have a hose ready and treat it like hair dye, always do a small test spot in an inconspicuous area -

...

compu_85 · #28 12-20-2009, 01:03 AM

Wow, I could have sworn mine was painted

I'll have to get out the buff ball and see how much of old man winter's work I can undo...

-Jason

strelnik · #29 12-20-2009, 03:42 AM

Quote:

Originally Posted by Jeremy5848

I've been continuing to clean up my poor abused '87 a little bit at a time. The valve cover is starting to respond to #0000 steel wool and Mother's Aluminum and Mag Wheel polish and will eventually look pretty good. However, the crossover pipe and intake manifold look crummy, as you can see, and I think that they must have been painted at the factory. Can anyone confirm that, have pictures of what it is supposed to look like, knows what paint to use?

Jeremy

I would use the finest scotch brite, about 1200, on the valve covers. That's the best you'll get unless you have the aluminum professionally rectified, and I don't mean polished with ammonia products that further destroy the surface.

scottmcphee · #30 12-20-2009, 10:56 AM

It's time to SEE some refinished parts, according to how the posters are touting... pictures tell well. 'nuf talk. Show me your crossover and intake, and say what you did.

blast
bead
polish
powder coat
...
whatever

show it

I want to do this job too, and haven't picked a method yet.

By the way, the OP was never answered completely, the answer is MBenz used a engine metal protectant spray on these parts, that yellows over time.