924Board.org

[james elliott]

i need some help? I have a 1981 924 that set almost 3 years before it fell into my hands after checking fluids and draining the old gas that was in there and flushing all fluids, plugs , filters, the engine fired right up but was making a loud ticking noise. After removing the valve covers we noticed that one of the lobes on the cam shaft was worn and the cam followers were pitted. After consulting a mechanic who said he knew about porsche engines and had his own import garage, he replaced the cam with a new one and put in new followers and said everything else looked ok .
Now here's my problem after putting everything back together the car will not start unless you remove the air filter and manually work the mixture control arm behind it , and low and behold the engine still makes a ticking noise but as loud as before. Any suggestions on what my problem is besides not taking back to the so called expert, he also says now its a compression problem????????????

[Smoothie]

You can get a compression tester for probably $20-$25 and test it yourself so you don't have to wonder about what the mechanic is telling you. Get the Haynes manual too for reference. Check the valve timing and ignition timing - those things would have been messed-up, then re-set after the cam work, so if they weren't set right, they could be part of the problem. The air:fuel mix shouldn't have been touched, but who knows? Check for vacuum leaks and intake air leaks between the fuel distributor and throttle body - a vacuum leak could account for your having to manually richen the mix by messing with the air metering plate.
There's a small plastic elbow under the valve cover that delivers oil to the tube that distributes oil along the cam - make sure that was replaced.
_________________
"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[Roger]

I posted a reply to your question on pelican
_________________
1981 924 NA

Some people are like Slinkies. Not really good for anything, but you
still can't help but smile when you see one tumble down the stairs.

[gohim]

One worn cam lobe is usually a sign of inadequate camshaft lubrication due to plugged oil supply holes in the camshaft oil supply tube.

A secondary problem is the plastic elbow that connects the oil supply tube. When they get old, that shrink and crack, and leak, and the camshaft oil supply tube loses pressure.

My guess is that the mechanic did not clean the oil supply tube, and the same cam lobe is now being oil starved on the new camshaft, and/or the valve clearance was not properly adjusted on the new followers.

By the way. New followers/lifters cost about $75 each. That is $600 for an engine set. How much did you pay for the camshaft and the followers?

Anything less than $800-$900 for those parts alone, would indicate that you did not get what you think.