Billy Idle

Ok, not so many posts... but I'm now fully engaged with my S4 after letting her sit all last summer, & I'm now in the midst of a complete R&R on the intake & a cam oil plug/cover overhaul, complete with tensioner pad, & cam journal oil plug to pin upgrade.

Problem: driver's side, attempting to clean the oil check valve, & I've bent the 3mm Allen key trying to undo the lock screw. I'm guessing galvanic fusing/corrosion between the steel? screw & alloy block.

I'm thinking of heating the casting around the inside of the cam tower where the screw is with a torch or heat gun, & air duster can to freeze the screw from the outside, to try & break the corrosion between them.

BTW, I had a lifter clatter on this bank, before starting this... found the cam plugs soft & misshapen but still in the journals. Not sure if those were the culprit. I'd like to rule out the check valve as the cause.

Thoughts/advice appreciated. I may even pay for a membership





88 Venetian Blue 5MT LSD

MainePorsche

The bolt for the oil check valve was a bear to get my tools on. With a little toil I was able to accomplish it. If you really think it fused it will be difficult, if not impossible to lay heat right on it.
I remember I had tappet chatter on the passenger side. I removed the spring and the ball - they were practically spotless. I was compulsive about checking everything related to the chatter.The chatter was from those two hockey puck like plugs that were floating around under the cam cover. Call Roger, Mark, or whoever is your 'guy', and get the superceded journal pins that Porsche stepped up to. Those rubber things were a poor design doomed to failure. The pins will be a one time permanent fix.

Rob Edwards

The little grub screw/threaded rod (999 218 035 02) that holds the check valve piston in comes from the factory with some blue loctite on it, heat will help turn it out without stripping it.

Page 17-10 of the WSM has a good description of getting the piston out




+1 on the cam journal blockoff pins, this is what you need:

Mrmerlin

if you do take the check valve apart ,
make sure to test to see if the lower seat portion is indeed staked in place.
If the seat moves then it can possibly be lifted by oil pressure and thus cut off the flow of oil to the head then the cams will seize.
NOTE the seat lies under the Ball.

If yours is loose then remove it,
clean the surfaces use some green loctite and drop it back into place,
then stake the edges.

The primary function of the check valves is to stop the oil from flowing backwards into the pan,
when the engine is shut off.

The rubber pucks with pins can fall out and cause a loss of pressure to the head.

For the best possible chance of removing the threaded rod ,
I suggest to drain the block first,
then you can use a heat gun to heat the area.
if you leave the coolant in the block it will not be able to be heated hot enough to free the rod

MainePorsche

Guys, I did this procedure about 6 years ago and I have it stuck in my mind that I used a reverse threaded bolt for removal of the spring guide. I know have have this same clean bolt where I keep my specialty tools and materials.

Billy Idle

Thanks for the feedback guys.

I put the pins earlier this week. When I pulled the cam cover off, the old plugs were still in place but were soft & slightly deformed.






I'm going to try some heat to get the lock screw out, but I'm not going to risk breaking something. I have a sense it may not be the source of the cam chatter anyway, I just wanted to clean it while I have the opportunity.

The chatter occurs whether hot or cold, but only at idle, off throttle. It's no louder at cold start up, which would indicate a passing check valve.
I just uploaded a brief phone video, I took earlier this winter, where you can definitely hear it...



88 Venetian Blue 5MT LSD

Mrmerlin

when was the last oil change?
how many miles on the engine?
how much driving has been done since the video was made?

Billy Idle

The car has made this noise since I've owned it, 4 yrs at 200k km.
I've put less than 6000 km on it. I've changed the oil spring & fall, regardless mileage.
Running Castrol Syntec 5W-50 (that's going to open a can of worms). Tried Mobil 1 15W-50, but the Castrol seems quieter.
I haven't driven the car at all since the video... I pulled it out of the garage, to do some work on my daily driver.
Right now it's on jacks, with the intake & cam covers off, out for powder coating, while I do the R&R.

I've yanked on the cam chain & tried to press in lifters with my finger, there's nothing obvious. I am replacing the tensioner guide pads.

I don't want to pull the head, just to clean the check valve. I'll finish the intake, replace the cam plugs & see where I am. I don't multi-task as well as my wife, & I have enough zip lock bags full of bolts & things right now.

Collapsed, sticking lifter(s), worn cam? Won't know for sure until I button it all back up. Then I'll try the Swepco 502, before I go back in.

I'm still hoping it's the cam plugs... as I said, under throttle, there's no chatter at all, & she hauls!

Billy Idle

Eureka! I got the lock screw out. Left it with some Rem-Oil I wiped on with my finger (not sure if it really helped), & left it for 2 days. Tonight, a couple of minutes on the cam tower just above the check valve with a heat gun, & on the second try at putting some tension on the Allen key, "Click," it freed up. The Check valve & seat seemed pretty clean, so no issues there. The O-ring seal was dry, so replaced it & back in it went. I did notice two indents on the 'plug' from the grub screw, so someone has been in there & inspected this before.

Note the bent Allen key from the first attempt.





Onward!