Cloud9...68

Never!!

jax

Carslave,
Can I check the lifters without removing the cam? Of course I would rotate the cam so the lobes are pointing up and test each cylinder sequentially. This vehicle was driven 2-3 days a week about 30 miles each time. My balance belt was a little tight and so the car whined more than she clanked. Do lifters "dry out"? For example if the engine had not been run in the month while performing this service? I drenched the top end with oil before turning her over (without DME relay), and then let her run when everything seamed to be in order.

Cloud9,
I don't recall the engine making this type of noise prior to dis-assembly. The etc, included a new oil pump drive gear/o-ring/washer, belt tensioner/belt tensioner bolt/clips/o-rings, and all new rollers. I tried to torque the main crank bolt to 155, but it ended up just being my body weight dangling from the torque wrench. Oil pressure at the gauge is 5.

mbardeen,
I did not remove the back cap, and both plugs are in there. I dont think there is a plug (or supposed to be one) on intake cam side at the front of the engine.

Alan, I may have to go that route! It just seems like I have just as much experience with these engines (none) as the local experts. It is the SF Bay area though so I'm sure there must be someone!

The only other info I have withheld is the disappearance of a long valve cover bolt (and rubber stopper and washer). I searched long and hard EVERYWHERE. Being concerned it fell into the engine I took another and tried to get it to fit into the oil drain galleries and it just wont fit.

I did not use the cam saddle tools but went slow when removing and installing the cams. That being said, maybe I bent a cam? Could this be caused by something like that or would the car not even run?

I truly appreciate all comments and recommendations (as well as Doug's help on the phone) you all have provided. Thank you so much.

car_slave

Yes - just press down on the unloaded ones and see if they budge. Lifters can make noise after sitting for a while. Also, make sure your cover retaining bolts went in properly. I recently got one wrong and it made a bunch of noise as it rubbed on the cam

tamathumper

Bear in mind the oil pressure gauge on the dash might not tell you what the oil pressure is in the upper end. I say might because I had an oil galley plugged with a cut off finish nail by a surreptitious previous owner of a 944S, and it caused my poor tensioner performance due to low oil pressure, but IIRC he had also rigged the oil pressure sender so it was always pegged at 5. Not something I noticed at the auction, but I found out later at great expense.

jax

I havent had a chance to investigate further yet. Is there a way to check oil flow to the head? Cut a hole in a tarp and run it with the valve cover off for a few seconds? Might be worth the mess, plus I have to drain the oil anyway. Im kind of joking but not by much.

Cloud9...68

Interesting thought, although the challenge will be not knowing what's a "normal" amount (if any) of oil gushing out of the top of the head. I googled how to test for oil flow to a cylinder head, and nothing came up. The only thing I can think of would be to remove the oil feed line to the variocam, and attach a line with an oil pressure gauge. Kind of like the attachment you had to use when you timed your cams to pressurize the variocam with air, except in reverse. But again, not knowing what a normal oil pressure reading at the inlet to the variocam is makes interpreting the result a challenge. Of course, if the reading is zero, you will have identified a definite problem.

jax

I found the valve cover bolt!!! It bounced off the ground and into a small oval hole on the inside side of one of the wheel ramps. (No the car is not off the ramps yet). So at least I know that is not the problem. Im anxious to check my lifters but hav not had the chance.

Cloud9...68

I seriously doubt you'll be able to check whether your lifters are defective or not, unless you go to the trouble of removing them and then finding severe corrosion on them. They're very simple devices - as long as oil is getting to them, they will do their job. Besides, your engine wasn't making this noise before the work you did, so why would you think your lifters suddenly decided to stop working?

I'd focus on coming up with a way to confirm that you're getting oil flow to your head, which may be easier said than done, but somebody somewhere must have devised a way to check this. As I said, at least conceptually, connecting a line with a pressure gauge attached to the variocam's oil inlet would be one possible way, but there must be others.

RajDatta

+1.

RajDatta

Bending cam would be next to impossible. I doubt that's your problem. Sounds like oil is not pressurizing something. How long have you run the engine after putting it together.
Sometimes it takes a few mins but be 100% certain that variocam check valve was put back in.
A good way to check if your oil pressure gauge is rigged is by turning the ignition key on without starting the car and see what it reads. The oil pressure should be 0 with the ignition key on.
If you run out of ideas, drop me a PM and I will give you my contact.

Cloud9...68

I agree. Somehow, you don't seem to be getting enough oil to you head. There must be a way to attach a pipe or tube with a gauge attached to the thread that connects your variocam oil feed line. You might want to consult with a local hydraulics shop.

jax

So, I have been / am very much consumed by the birth of my firstborn and first home purchase that I have been unable to resolve this issue... until now. My mother-in-law is in town visiting with the baby which meant it was the golden opportunity to fix the Porsche! After spending Friday through Sunday cleaning and organizing the garage so I could park her (the car not the mother-in-law) inside and get back to fixing her, the strangest most wonderful thing happened! After sitting for a good 3 months I pulled her out of the driveway did a three-point turn so I could drive her face forward into the garage and right as I pulled in I noticed the terrible clicking noise all-of-a-sudden stopped. I put her in neutral and opened the hood and revved the engine a bit only to hear the soft whine of the BS belts. I think I may have a miracle garage. You just drive in your broken car, and whallah, fixed!

If anyone else needs the services of my garage Im sure we can make a deal.

Thank you all.

Paul Waterloo

Interesting read. So how many minutes/hours did you run the engine before the noise went away?

The Audi 40v engine has the same system, I've changed the "variocam" in them before....and it takes a while for all the oil to build up and pressurize the system. When they do go bad, they make the noise at start up like a diesel engine as a check valve or the sort that fails allows the residual oil pressure to bleed off. This allows for excessive wear on the plastic chain guides and a negative feedback loop for the whole system.

Jfrahm

Oh yeah it's Paul from the D2 A8/S8 forum. Hi Paul.
The 968 can get a chain slap sound but that is usually super scary and indicative of a really blown variocam unit and a chain that is slapping the cam cover. There is also lifter noise from lifters that are low on oil and/or plugged up, and in this case some time and clean detergent oil might have sorted that. A third noise is a weird little 'braaap' noise the variocam makes when it's somewhat worn, I think when it activates/deactivates. I am not sure what causes it, maybe slow activation or looseness in the piston in the middle causing it to shake until it's fully extended.

A clacking is usually not chain slap but rather lifters not fully pumped up, the last time I did a 4v head I almost reached for the Rislone when the noise quieted on it's own. I had not soaked the lifters before assembly.

Cheers,
-Joel.

tamathumper

The chain slap is a "staccato buzz" that turns to a frightening "razz" at higher RPMs.