I got the manifold off and this is what I found,...

overkill · 10-20-2002, 07:14 AM

SoCal said that if there was oil on top of the valves that it means that I have bad valve guides. The oil in the manifold and intake ports means excessive back pressure. He also said that the oil came from the breather tube,... where from the breather tube? What coul be the reason fro excessive back pressure? Does that mean that there is somthing wrong with my exhuast?

Makis · 10-20-2002, 09:22 AM

I doubt what you have there is oil. I believe what you have there is tar/carbon deposits from the fuel. You will need to take good time and clean it all up. Excessive back pressure may contribute to more depositing. High backpressure could be the result of a broken CAT.

overkill · 10-20-2002, 10:12 AM

REALLY! Dude I was complaining of a rattling under the car a while ago! My thats it! The noise was coming from the CAT area! COOL!

overkill · 10-20-2002, 12:23 PM

Ok, I cleaned th4e manifold to thebest of my ability, right now atleast. First,... that is not OIL! I couldn't get that **** off! I had to soak that fugger in HOT water to even come close! I removed and cleaned the throttle switch to a shine. Whats the best cleaner to get this **** off! I want to get as much of it off as possible! I heard brake cleaner is good, is that true or is there something better?

Makis · 10-20-2002, 01:22 PM

Quote:

Originally posted by overkill
REALLY! Dude I was complaining of a rattling under the car a while ago! My thats it! The noise was coming from the CAT area! COOL!

This may be, but the CAT has got a number of shields around for heat insulation. It may just be that one got loose and is rattling. It should be easy to inspect th CAT externally. Those shields will not stop the CAT from working correctly though. So your CAT may be damaged internally. The efficiency of the CAT can be tested for backpressure, check the manual. Also one easy way to do (but not very reliable) it is with a vacuum gauge. See this link

http://www3.bc.sympatico.ca/BOBLEVIS/vacugage.html

Makis · 10-20-2002, 01:28 PM

Quote:

Originally posted by overkill
Ok, I cleaned th4e manifold to thebest of my ability, right now atleast. First,... that is not OIL! I couldn't get that **** off! I had to soak that fugger in HOT water to even come close! I removed and cleaned the throttle switch to a shine. Whats the best cleaner to get this **** off! I want to get as much of it off as possible! I heard brake cleaner is good, is that true or is there something better?

Carb cleaner should be quite good, but this staff needs to be scrapped away.

overkill · 10-20-2002, 03:00 PM

Ok, this is what I got. I got this purple stuff from home depot that actually works very well. IT's made by zep. I also got one of those toilet bowl brushes with the blues bristles. The head looks like a gum drop. I shoved it in where the breather tube connects and scrubbed it out. It was very clean when I was done. Now i have to cut of some of the bristles so i can get it in the tubes of the manifold and scrub that out. Thanks for your help.

overkill · 10-20-2002, 03:39 PM

Am I suppose to bolt the throttle switch onto the throttle valve housing so that it clicks everytime the circular door just opens and just closes? That makes the most sence.

turbohead7 · 10-20-2002, 03:50 PM

Hey Overkill, sorry I'm late in responding to your post. What you have there is definately carbon deposits, not oil. This is completely normal on higher mileage 944's. Although backpressure blowing oil into the intake is entirely possilble, if your cat was that plugged up you probably couldn't run the car. I've removed plenty of 944 intakes and saw this condition, so don't worry. Carbon deposits can come from a number of places, including an overly RICH mixture, so make sure the O2 is up to date and the pressure regulator is OK. Carbon deposits can also form from dirty gasoline, try using Sunoco. Porsche actually reccomends Chevron or Exxon both known for their clean fuel/superior additives. Make sure you've replaced the fuel filter recently. Insufficient combustion can also force CO or partially unburnt fuel back up into the intake, so make sure your ignition system--especially the plugs are in good order. As I'am sure you already found out this stuff can be particularly nasty to remove, I've found that soaking the bad areas with carburetor cleaner and good old fashioned scrubbing works best. Be careful with the Home Depot cleaners as some are very corrosive and should not be used with aluminum. Good luck and happy wrenching!

turbohead7 · 10-20-2002, 03:54 PM

The throttle switch is a two position switch, it tells the DME whether the throttle is off idle, or wide open. Unlike a TPS which tells the fuel controller exactly where the throttle is. It should click just as the throttle opens, and at WOT (wide-open-throttle)

overkill · 10-20-2002, 04:27 PM

Cool, thanks turbohead7! I am just about ready to continue my venture. I have to finish writing notes and cleaning up.

CJFusco · CJFusco's Garage

RE: Cleaning....

Simple Green, my friend, Simple Green.

overkill · 10-21-2002, 06:07 AM

I have simple green too,...