Clean Up Your Engine Bay Young Man!

As you may have already seen this is what the engine bay of our 1983 Porsche 928 looked like upon purchase.  Complete but in obvious need of some serious clean up and general TLC.  The dirt and carbon deposits are pretty obvious.  This all needs to be cleaned up in a big way.  Being a bit of a barn find it is important to give the entire engine bay a good once over, to ensure that no foreign debris is lodged anywhere that could cause damage to the engine or potentially cause a fire.

We pulled the air filter out of the air box and found that a furry creature of some kind, most likely of the chipmunk variety, had been making a home in the air box.  It was also clear that Chippy had a thing for acorns.  I guess in the mind of a chipmunk the trip through the air tubes up each side of the engine to the air box made a perfect place to hide/store nuts.  Basically a den with two exits. Fortunately there was no real damage done and also no bodies to remove.  After a good vacuum of the air box it was now 100% nut free and safe to be within 100m of an elementary school. The first move in the clean up job was to remove the air tubes running on either side of the engine bay and the air box they connect to which is at the very back.   Once off you can get a good look at the inside of the mass air flow sensor unit (picture below on the left) and the back side of the air guide housing itself (picture below on the right).   You can see there is a lot of dirt and oil inside. 

The oil was coming from the oil separator.  This is the black can with the yellow knob you can see in the engine bay picture above. Interesting thing is, the black can is actually silver!  See dirty picture to left and clean to the right.  The black is years of oil leaking down the side of the can.  This is a symptom of a missing gasket.  These two pictures give you a decent contrast of the before and after.  Without that gasket oil leaks down the cup and ends up all over the rubber coupler that holds the throttle body to the air plenum leading to oil in your air.  Not really ideal.  To really get to everything the "spider" needs to come off the top of the engine.  This is pretty straight forward as long as the <CENSORED> bolts are not seized.  In my case only one single bolt was seized and it took three times as much time to free as all the others combined!  Heat, penetrating oil, TNT nothing worked. OK maybe not TNT. In the end the bolt was not seized to the engine head, thank God, it was seized to the leg of the intake manifold and after much inch-by-inch work it came free still stuck in the leg.  The picture below shows the top of the engine without the spider except the offending leg.  See it sticking out there.  Just laughing at me.  Telling its friends what a loser I am. Yes I heard you!  Who's laughing how eh?  But I am not bitter.

Once you get everything off you can easily do a good clean up of the throttle body. It is always a good idea to replace the rubber Plenum-to-throttle-body coupler as well as its two hose clamps. While you have the air guide housing and throttle body exposed check the little bonded rubber buffer mounts.  They will most likely have separated  giving the air guide housing the ability to move about. Not really what you want.  The picture to the right shows a new mount at the top and half of a separated one on the bottom.  Once these separate they can be an absolute <CENSORED> to get out.   The two pictures below show one of the air intake legs and the plenum on the bench. The tape measure gives you some perspective on the size of the two pieces.  These pieces need to be scrubbed down to remove all the dirty and carbon deposits.

This was a very messy, manual and tedious process.  A Varsol tank would be a plus here but if, like us, you do not have one in your garage, you can get by with a smaller rubber maid bin, a collection of wire brushes (not too course) and medium steel wool.  Keep the brush and the steel wool wet with the solvent of choice to ensure you are not too rough on the surface of the parts.  You will find this takes time and patience but the end result is worth it.  

I considered powder coating the parts after seeing some of the pictures in the forums.  It looks very nice and super clean.  You can even choose the colour you wish to use to match any colour scheme you have going on under the hood. Once we got them cleaned up it was decided to stick to original as much as possible To do the  actually cleaning chemicals were required. I used copious amounts of the liquids depicted in the picture to the left.  Really you should feel free to substitute your favourite or preferred. Rest assured you will require far more of the one in the bottle than the others combined.  Far more!

After all the cleaning is done the reassembly begins.  This was far easier than the tear down.  New gaskets will be required for the air intake legs. The old gaskets must be completely cleaned away from the top of the engine and the bottom of the air intake leg.  After the spider was completely back in place I re-installed the injectors on the fuel rail (see previous post).  Before I did this I replaced all of the rubber inner and outer bushings on each. (See picture to right) This helps ensure a clean seal and tight fit.  We do not want any air leaks.  After that the reconstructed rubber fuel lines were also put back into place and new air tubes were installed.  The final result is shown in the picture below.  Quite a contrast to the original state of the engine bay as seen in the picture at the beginning of this post.

All that is left now is to reconnect the fuel lines at the back of car and to see if it will start again after all this work.  Cross you fingers!

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