Boost leak check
Still can’t see the needed area of the uppipes well enough for a positive determination. Usually leak at the section directly below the clamp. You’ll need to check both sides.
In the pics the truck looks very original. Good find! And with 300k the OEM up pipes are surely leaking. It's a design flaw. One of your pics almost got it; put the phone close to the up pipe. Looking for soot on the up pipe blown down from the cast iron collector above. There is cheap short term fix but I recommend the cure, bellowed up pipes. And yes they can be a biotch to install.
For the air cleaner either keep the K&N and resolve to keep it clean, or switch to a 6637 kit.
Driver side up pipe... looking at firewall and down
Driver side up pipe... looking at firewall and down
Looking at turbo pedestal
Looking behind turbo exit
Spider, looks like leak on both lower passenger and lower driver side
Lower driver side of spider, looks like it's leaking too
Driver side
Looks like leak or spill from power steering
Looks like leak or spill from power steering
Looking at driver side of engine valve cover
Looking at driver side of engine valve cover
I went looking for more soot and took a bunch of pics. Didn't see soot that jumped out at me. I took a bunch of pics. And I really could only see the driver side of the up-pipes. I couldn't really get any good view of the passenger side up-pipe.
I did notice some old oil leak - looks like possibly from power steering?
This is the area the uppipes are most likely to leak and what I was interested in seeing. It seems like there may be a tiny bit of soot here but not bad. We need to find a way to check the other side. Also check down where they meet the manifolds.
I would check the manifolds well. Can’t tell from the photo but that may be a little soot. My truck has had issues here. Found mine by doing a cold startup and feeling for leaks. The second one was located with a endoscope finding soot behind the manifold. This is NOT a fun job. We can give you pointers though if you end up needing to reseal them.
I would check this first. The CAC is known for wearing a hole here with contact to the PS line or fitting. Lots of oil here and below makes this very suspicious.
I noticed the crazy amount of old oil leak at the PS hose. I figured it was someone lazy trying to fill the PS steering oil. I really should get that all soaped up and cleaned to see if there's any new fluid leaking (and from where).
Now... just gotta wait for it to stop snowing and just warm up above freezing. It's super hard to do anything at the moment with the cold. Can't really feel my fingers or hands when I'm out there so feeling for exhaust manifold leaks with my hands may not yield results.
Thanks again for the suggestions. I'll report back as soon as I can (probably a week given the weather and only having weekends to work):
1. Tighten all the CAC boots
2. Clean the area near the PS reservoir
3. Boost leak test at all clamps and locations prone to leak
Ford Trucks for Ford Truck Enthusiasts
You may need to pull the CAC to see if there’s a hole in it. Might be able to check it during a boost leak test.
Orange boot with standard hose clamp?
T bolt clamps are a nice addition, but can deform the factory plenums. Add a set of Riffraff plenum inserts while doing the job. They are cheap and easy to install. Adds rigidity to the factory plenum so you can crank down the clamps.
Link to plenum inserts L99-03
I haven't gone after these leaks yet. Interesting one is the one on top of the engine. Anything special I should consider besides tightening nuts and possibly cutting air lines shorter and replacing with hose clamps? I'm not sure what the line is on the engine. Should I just tighten that?
Well good news, fixing those leaks will surely help performance.
Bad news, that plenum leak won’t be a fun fix.
This is manifold air temp sensor. Mine was leaking as well. I replaced with one from a part store
even though sensors are preferred to be Motorcraft. Then I stood it up on the end and epoxied the outside of the original and placed in my spare parts box. Kind of wish I’d have tried that first.
This is a plenum leak. I had one of those as well. Motorcraft TA-31 silicone for the repair. Riffraff sells billet plenums with an oring if you want to go fancy. It’s not leaking from the hose if that’s what you were asking. The braided line is a high pressure oil from the HPOP.
Air Intake Heater. Try tightening the large portion. You may need to loosen the nut so the wires have play. But you’ll be pulling the turbo for the plenum repair anyhow….
Sorry to be the bearer of bad news.
Edit: Tpayne621 types faster than I do!













