rdewert

IMG_1170.MOVHave been totally baffled by my 993 C4S ticking noise. Have had all the lifters replaced and it still ticks.
The car runs good but has a noticeable miss at idle.
Are there different size lifters for these engines?
My indy put them in but he is baffled also.
Any thoughts are much appreciated.
Thanks in advance.
RD

JasonAndreas

Have you tried to pinpoint the source of the sound with a mechanics stethoscope?

Andy Hodapp

Did he make sure to soak the lifters in oil first? Where did you get the lifters from? Possible one could have been bad right out of the box. Also would love to see some pictures of the car, what color is that? Looks amazing!

windydog

Check for cracked spark plugs wires.

rdewert

Have used my stethoscope and the noise seems to come from the left side at #2 or #3 cylinder but it difficult to pinpoint with the engine running.

rdewert

Thanks Andy. I'll check with my indy. The lifters came from the Porsche dealer.
The color is violet metallic. 49.5k miles

rdewert

I'll check the spark plug wires. I did disconnect both spark plug wires on #2 and #3 but the ticking is still there.

nine9six

Possible exhaust leak at any one of the various connections?
Exhaust leaks so often make a ticking sound.

Churchill

That is LOUD. It also doesn't sound like lifters. I would take it to a better mechanic. Hard to diagnose these things over the internet, but could be an exhaust leak. How much oil does it consume? Very badly worn valve guides can sound like that -- it's the valve head beating on the valve seat.

Again, Step 1 is get a better mechanic. Your guy sounds lost, and you've already wasted hundreds if not more paying him to blindly swap out parts rather than correctly diagnose the problem. Move on before you waste more money.

Endoman

Many moons ago, when I was a student a friend had a ticking/tapping noise coming from his Ford. Car ran ok, no oil smoke. It was a 4 cylinder ohv engine with pushrods and rockers. Rocker covers removed, nad. Compression was a bit low on one cylinder so I pulled the head to find a piece of broken piston ring embedded in the crown of the piston. It was a small piece of the top ring. As students the cheapest quickest fix was a new piston, the top land ot the piston had a piece missing and the bore had very light marks. New b/e shells fitted and the car ran fine, well enough to sell it at the first opportunity.
Worth having a look with a bore scope and a leak down and compression test but I do hope that is not the problem as the fix will not be so cheap or easy.
I have seen a 3.2 engine with a stretched timimg chain where the tensioner was touching the casing but it was pretty easy to spot it was coming from the front of the engine.

rdewert

Thanks very much. Problem is there are very few indy mechanics left to diagnose these cars. Even the dealers don't have many mechanics who can work on air cooled engines .

rdewert

The car uses no oil. Very low oil use. I did switch to 20w/50 Penn Grade from Mobil One on the advice of a good 911 shop in Indianapolis.

Churchill

Where do you live? You don't need an air-cooled 911 specialist to figure out why your engine is missing at idle and making a loud knocking sound. You just need a competent mechanic. There must be one in your community.

Cheekybird

I know of several great shops in the midwest, less than 2 hours from Indy in Cincinnati and Columbus.

http://kraftwerksperformance.com
http://northendwrenchinc.mechanicnet.com
https://www.hhmotorcars.com

Nadim Eid

hi, I have exactly the same problem. Replaced all 12 lifters and i have the same noise on the same side of the engine.
When the engine is cold, it´ s smooth and quiet

did you solved it?