[Zipway]

Hey everyone,

I've been perusing the forum for a while - I love this community. Makes me happy to have chosen the ST. I'm looking for a bit of help. I bought my ST a few months ago to replace my Focus SE which was tired of me driving it so hard. I purchased the ST already modified with most of what you see in my sig (big turbo + forged engine build + dual catchcans + etc). (13,000 miles on the clock right now) It drives great and seems to be tuned well, but recently noticed a pretty significant oil leak (enough to cover the rear motor mount with oil over the 1 tank of gas since I last degreased it.) I can see it dripping from the driver's side of the valve cover (which then covers the rear motor mount and the back of the engine) I'm afraid there may be leaks near the crankcase, too, as there's also some oil dripping from the passenger side as well. (See pictures - oil circled in red)

Last week I took it to the dealer who was nice enough to consider me for warranty work, despite the mods. The dealer blamed the big turbo (tuned to 22psi) and aftermarket PCV system for overpressuring the crankcase. After that I took the whole PCV system apart and verified its function and check valve direction. The dual can crankcase vent system seems to be doing its job correctly. That's when I found the leak is almost certainly coming from the valve cover. The thing is I see in the car's maintenance history that they've already replaced the valve cover gasket once since the engine build due to an oil leak. In the 5000 miles since that service, the leak seems to have come back.

Not sure why the valve cover would leak again, even after a seal replacement. Anyone have any thoughts? Should I be considering a new valve cover entirely instead of just a gasket replacement? And any idea on what to check for the passenger side leak? - the dealer said the crankcase seal was leaking, but I'm skeptical. Maybe the other side of the valve cover?

Thanks for your help, guys!

 

[blinelaxd27]

hmm that's a pretty heavily modified car so could be hard to diagnose and the dealer may be hard to work with.

my valve cover was leaking when I bought my car and had the dealer replace and no issues since then. I would replace the valve cover gasket/rtv and go from there so that you are not chasing 2 issues at once.

 

[Zipway]

hmm that's a pretty heavily modified car so could be hard to diagnose and the dealer may be hard to work with.

my valve cover was leaking when I bought my car and had the dealer replace and no issues since then. I would replace the valve cover gasket/rtv and go from there so that you are not chasing 2 issues at once.

Probably a good plan - I'm a bit hesitant to replace the gasket because that same job was done just a few thousand miles ago by a shop who verified no leaks after their replacement. Any thoughts on what could be causing the leak to come back? I was thinking of maybe replacing the valve cover itself when I do the gasket (looks like it's only $50), in case it's warped in some way.

Does anyone know of any writeups on doing the valve cover gasket? I have the service manual and it looks pretty straightforward, but I'm sure there are some caveats not mentioned in the manual.

 

[Zipway]

Updating this thread for the sake of anyone chasing this issue in the future. The dealer ended up tracing this leak to the high pressure fuel pump. They covered it under the powertrain warranty. The leak seems to be fixed for now! See invoice below for specifics:

MOTOR OIL LEAKING.
verified oil leak use engine oil dye to pinpoint leak to
fuel pump(injection) housing leaking...rr fuel pump and
housing and replaced gasket and retest ok at this time...

PARTS------QTY---FP-NUMBER---------------DESCRIPTION---------LIST PRICE-UNIT PRICE-
1 CB5Z-9276-A GASKET WARRANTY
1 AA5Z-9E583-A SEAL WARRANTY

 

[yue0707]

Hmm i'm having leaks in exactly the same place on my 16 Focus ST w/33k miles. I'll let the tech know tomorrow when I take the car in. Thanks!

 

[Blackula]

Recurring Valve Cover Oil Leak & More?

Hmm i'm having leaks in exactly the same place on my 16 Focus ST w/33k miles. I'll let the tech know tomorrow when I take the car in. Thanks!

Still have your sound symposer installed? The symposer valve attached to my battery box was rubbing the fuel line, and the factory even put some cellophane tape over that spot in the hose, like that would protect it. I'll admit no one else has reported that or responded to my comment when I've made it a few times, but as that dude in Amadeus says, "Ah, there it is."

Edit: someone else did confirm thru PM that their symposer was rubbing the fuel line.

 

[yue0707]

I was thinking about removing that since I don't use it anymore, but after doing the downpipe installation a while back, I didn't notice any leaks.... Oh wait omg... Now I remember, there a huge puddle of fluid right below the symposer valve where the shift linkage is on top of the transmission.

Ford.... Why, just why lol. No wonder my oil has a ton of fuel in it and I lose a quart every 1000 miles. I'm almost 100% sure it has everything to do with this. The turbo on the cold side also has oil all over it and the BOV as well as the engine block. Never smelled burning though and you would of since the ventilation system is right above the exhaust. I notice the PCV has been working overtime if I look inside the charge pipes. God this car's a mess. 2016 with 33k miles and I feel like I have a car from the 70's in terms of maintenance.

Yea its Stage 3 but I honestly think these leaks have nothing to do with it. Its been like this since 15k miles, just getting slowly worse and worse. I explained this problem to the dealer, got routed to the manager so i'm still waiting for a call back to see if they can take my car in. If they deny me because they know all my mods, no problem. I know the parts that i need to get and i'll do it myself. Not gonna cause trouble with the dealer and play cat and mouse with them. Been there done that, never doing it again.

 

[SIstomper]

If the motor was rebuilt and the rear cam caps weren't rtv'd properly it'll leak no matter what. Here's a pic of a motor I just took apart and you can see the rtv under the rear cam caps