Edit to make sense :-)

So as I am in the middle of backdating my exhaust system, it was hard not to notice how much oil/grime was in the heating tubes (everything that connects to the exchangers and heater hose under the car).

On each side there is a connection to the fan houseing and I am assuming that that's where the grime comes from. Seems like there should be some kind of filter or something to keep the tubes from getting filled with crap.
At least that's how I felt after spending a day trying to clean 'em out.

The parts that connect are at the front of the fan housing. Think of it this way... Anything that goes into the fan gets blown through the heat exchangers. Got an oil spill on the topside of the engine? Expect some of that to get sucked in the fan and blown through the heat exchangers and heater hardware. Water and some dust in there? You got mud.

rob, anything leaking from the front of the engine (main seal), vapors in the engine bay in general, are going to get pulled in by the impeller fan and shoved into the ducting and he's, recoating everything. a BIG reason to make sure all of the tin seals, oil fill tower seals, spark plug boots, etc, are intact and sealing. if your imp housing was all gunked up prior to the change, and you didn't clean it, you just started pushing the crap into your new hes and clean ducting. if the old system was a mess, the ducting forward of the heat control valves is prob loaded too.

k

Actually the reason I posted this question was due to how messy the heating parts I obtained from someone else were. The heating bits I took off of my car weren't exactly spotless though either. I know I have an oil leak (or two). I'll probably take some photos at some point and see if someone can help me diagnose where it's coming from. Unfortunately I don't have the space at the moment to drop the engine to really clean things up.

They all seem to be that way. I was amazed how much grime was in the blowers.

Welcome to the world of 30+ yr old 914's

did you try the oil eater?

k

Yup, worked like a charm! Thanks Kevin. They are all ready for some high-temp paint now.

After painting, I'll be installing a timesert and a 9mm x 8mm exhaust stud to repair the one that stripped out soon too.
Then I should probably see where the oil leaks are coming from. My guess is that one of them is coming from the oil cooler- maybe the oil cooler seals? Seems to me I saw someone say that the oil cooler seals could be reaplced with the engine in the car.
With any luck I'll have the exhangers on within a couple of weeks.

Off to temp the 914 world search engine gods to see if I can find some info on installing oil cooler seals....