Cam Shaft Seals

[Dave 53]

First start 3 days ago! Huge milestone! I've been letting it idle in the garage looking for leaks and any other issues and after about an hour and a half total idling over 3 days, drips of oil from the timing belt cover under the cam shaft. I was fine chasing coolant leaks, but this oil leak is a big depressing setback. 99.9% sure it's gotta be a cam shaft seal leak.

2002 WRX. Can the cam shaft seals be changed without pulling the engine? Can't tell if there is enough room to work. Seems doable without pulling the engine, but if not, I'd rather find out before trying and learning the hard way. Any cam shaft seal tips appreciated.

[NevaLift2Shift]

First start 3 days ago! Huge milestone! I've been letting it idle in the garage looking for leaks and any other issues and after about an hour and a half total idling over 3 days, drips of oil from the timing belt cover under the cam shaft. I was fine chasing coolant leaks, but this oil leak is a big depressing setback. 99.9% sure it's gotta be a cam shaft seal leak.

2002 WRX. Can the cam shaft seals be changed without pulling the engine? Can't tell if there is enough room to work. Seems doable without pulling the engine, but if not, I'd rather find out before trying and learning the hard way. Any cam shaft seal tips appreciated.


Yes, I've done this for that exact same reason, then I realize my STI cams never had the AVCS holes plugged. I would highly recommend a cam lock tool, Company 23 works great. You will need to pull valve covers to hold the cams while you remove the cam gears. I would highly recommend using OEM cam seals or high quality seals (i.e. Not Felpro).

[Dave 53]

I did it. First of all, if you have the engine out (yet to be installed), I think everyone is in agreement that it's a good time to do a timing belt, water pump, etc. Do your camshaft seals too! They should last 150,000+ miles, or they might not. Also if you are starting a build, I suggest NOT installing the firewall until after several successful (leak free) go kart runs. Let your car idle in your garage for about an hour+ after that glorious first start to see if there are any cam seal or any other leaks. (I had to chase down a few coolant leaks too). There are many reasons to need access to the front of the engine, especially the right side, so when you finally install the firewall, don't glue it in. You may need to remove it in the future.

There are several good You Tube videos on EJ20/25 timing belt and camshaft seal jobs. Watch them, take notes (blot torques, tool sizes, etc.) Here are a few notes on how the job is different with the engine in an 818 vs. in a Subaru or with the engine out of the car and tips I didn't see on any of the videos.

1. If mileage warrants it, get a new timing belt. If not, use a white paint pen to mark the belt / pully match-ups before removing. A new belt should have these marks, but they will be worn off a used belt. My belt had about 2 hours of run time on it and I could just make out the marks.

2. Remove the timing belt by removing the idler next to the crank opposite the tensioner, and then remove the tensioner.

3. There are a few You Tube videos on how to remove the cam pully by using an old timing belt and some vice grips to hold the pully. Since I didn't have an old timing belt and it looks like a sketchy method, I bought the ELK cam pully holder on Amazon. It required a small bit of grinding/ filing to get it to fit. Reading the reviews, it seems many others have the same issue. It took me less than a minute with my 4 1/2" cutting wheel, but if you don't want to have to do that, get a better quality tool. The ELK tool was fine after I grinded it. No need to remove valve covers.

4. You'll need a 10mm hex socket. I had to trim it down (4 1/2" cutting wheel) to fit between one of the cam bolts and the frame. My bolts came off without any issues using the 10mm hex socket (you'll find many videos about bolt removal issues). It just took two people, one to hold the cam tool onto the cam pully and the other to crack the bolts with about 3 feet of cheater pipe. 141735

5. To remove seals, drill an 1/8" hole in the seal, then use a 2" #8 wood screw to pull the seal out. Drill access to the exhausts cams was an issue. Use a 90 degree hex drill adaptor with a stubby 1/8 hex drill bit available at Amazon. 141736

6. To pull the seals, I used needle nose plyers and a scrap of wooden paint steerer stick. Use the wood to protect the end of the cam shaft. Tip of the plyers on the wood and the screw in the crotch of the plyers. Test your plyer orientation to determine where to drill the hole. Heating the seals with a heat gun made it much easier. Actually, I was just pulling the screws out of the seal before heating, so heat was a must.

7. A 1 1/2 inch PVC pipe plug (pictured above) worked prefect to set new seals.

8. I didn't see any good tips on reinstalling the timing belt. Through trial and error, here's what worked for me...
8a. Wrap the drivers side exhaust cam, then the intake cam. Use a pair of vice grips and a popsicle stick to lightly clamp the belt to the top of the intake pully.
8b. Wrap the passenger side exhaust, then intake pullies.
8c. Install the idler.
8d. SLOWLY press the tensioner pin back in in a vice. Hold in place with an allen wrench. Install tensioner. 141734
8e. 5 times, make sure the timing belt marks line up with the pully marks.
8d. Pull the allen wrench from the tensioner.

In summery, the biggest difference between an 818 and a Subaru or with the engine removed is cutting the 10mm hex socket and using the drill angle adaptor with the stubby drill bit.