Nadim Eid

I had ticking noise on my 96 993 Carrera 4s since I bought it in January 2016. Last year I decided to have the engine Rebuilt by professionals here in Czech Rep. They changed exhaust valve guides, piston rings, chains, crankshaft bearing shells, connecting rod bushes, main bearings, etc... Crank shaft was cleaned and polished and heads were sent to another company to do the guides, valve seats, etc...Injectors were cleaned and rebuild as well. ALL lifter were replaced too. Plugs are new, plug wires too...

Before the rebuilt, as I mentioned, I had a ticking noise (only when engine was in operational temperature) on the left side of the engine, but my oil pressure was as It should be, around 4-4,5 cold and 2-2.5 when warm. The ticking was present thru all range of rpms.

Now I have still ticking noise present (although less pronounced and only on idle), but it is present, when the engine pass "8 hours" mark on temperature gauge. Oil pressure shows 4 bars when stone cold, after 30 seconds it goes down to 3 bars and then it stays around 1.5 bar till the engine gets warm (9 hours) and then its showing less the 1 bar. When I rev the engine, It goes to 4,5 bars already from 2500 RPM.

Please check videos. Car is in operational temperature and ticking is present on idle from left bank.

I have some possible causes on my mind:
-maybe the chain tensioners are installed not correctly, and the oil flow is compromised by this.
-some lifter/s can be bad even when new and bad pressure sensor
-Pressure reales valve stuck
-bad rocker arm and rocker shaft and bad pressure sensor
-bad cam and bad pressure sensor

Thanks for your insights


and



Here revving it a bit

95_993

It sounds like ticking lifter to me. Do you know if the shop pulled and cleaned the oil spray bars in the cam towers? They have very small holes that can become clogged, leading to premature cam wear. It's likely they dis given everything else they did, but just thinking m.

I would try to isolate which cylinder is ticking the loudest with a stethoscope or something similar, then pull the valve cover to inspect cam lobes, rocker and valve clearance per the shop manual, although that requires a new, dry lifter.

Lastly, I would ask what oil you're running? Sorry, I have to ask. If you're oil is a lower viscosity, it will show up with lower oil pressure at operating temperature. It could be as simple as running 15w-50 or 20w-50 and seeing if you pressure comes up to the usual 2-2.5 at idle.

Nadim Eid

Hi 95_993,

I am using Motul V300 15w 50 now, but before I was using Mobil 1 0W 40. Oil didn't change anything.
I am listening around the engine with stethoscope for some time now, and it is not very easy to isolate the exact side (upper/lower) or cylinder, from which the sound is coming from. It sounds clicky clacky everywhere on this engine...
According to spray bar. I suppose, they did, because this gentleman has a big name in Porsche restoration business here in Czech Republic. I saw some pictures during engine assembly process, and everything was very very clean, before they put it on the engine..

I believe that the lifter is very possible cause. If I measure the valve clearance, do I really need to install new dry lifter? I believe, that if I turn the engine to position, where valves will be closed for the particular cylinder, I can measure it with installed lifter as well..

Cheers

pp000830

Hi Nadim,
993 engines can be noisy with valve noises. May be normal. I had a tapping valve noise for a long time that went away after several months, Carbon debris in the valve seat maybe?
There are oil pressure relief / regulating valves on the bottom edge of the engine case halfs facing to the right opposite the drain plug and another pointing down, see the picture below.
They have a spring and other parts under their caps that if hanging up or missing can result in loss of oil pressure.
Also, your pressure sender or gauge may be a little off.
If your oil pressure is truly low it can explain greater valve noises.
https://rennlist.com/forums/attachme...lief-valve.jpg
Andy

Nadim Eid

hello Andy,

can I remove the pressure valve without loosing all the oil fill?

thanks

rk-d

I'm not sure what's going on with the oil pressure. Posts above have good thoughts.

The valve lifters are noisy. It's normal to hear a little ticking in the wheel well. If you are hearing a louder clacking, then it's a problem.

pp000830

Hi Nadim,
Only a small portion of the oil fill rests in the engine case. One can capture it in a small pan and put it back in afterward.
I suspect the spring and the little piston are inexpensive and so just replacing them and seeing what happens may be a good option as an experiment. If any metal debris from the engine break-in period has interfered with the valves' action just removing the spring and piston and putting it back in would probably release it.
Andy

geolab

Hello Nadim ?

Your engine ticking is 100% normal, this is the 993 engine sound .
When you cold start the engine, pressure sensor should show at max, slightly above the 5 level. and warm temperature idle, should show 2 or slightly above
Since cold yours show 4, so it is showing 1 at idle, this sometimes trigger the pressure light warning on dash
But these pressure sensors are really not accurate, because they are of the Rod type, and a slight nano particle inside could render the sensor obsolete
The 993 oil pressure senders ar made in Czech, by VDO
Change this sensor and enjoy your car
. I also changed the lifters myself and It had the same sound as yours before and after enjoy

You asked the same question here on Rennlist in 2019 with an audio file, and my opinion never changed

Gbos1

me thinking …… he had his engine rebuilt over some ticking from a 993 engine I mean…. Was your engine burning oil at a rapid rate as in < every 500 miles and adding a Quart?

Nadim Eid

Hi everyone

actualy it was burning 1l per 700-800 km. We found, that the exhaust valve guides were worn. Oterwhtise good Healthy engine. It was also leaking oil quiet badly from one cylinder and bearing were totally shot on rear differential, so It needed some love everywhere…

by the way, I measured oil preassure with external gauge yesterday and it shows exactly the same pressure like the Sender, so sender is not the problem. I ordered both pressure release valves as Andy sugested. I let you know if oil pressure will show higher numbers or not

Nadim

geolab

how did you measure oil pressure with an external gauge ?

Without a gauge, technically speaking, cold start or hot revving engine should peg pressure at full max.
This is the technicality of the 993 oil system.
Your gauge does not show the same on cold start and rev, you said, 4bar and 4.5 bar, not normal

Nadim Eid

Hi,

I folowet the procedure and used the exact special tool mentioned in workshop manual
You just remove the oil temp sensor and screw in the VAG gauge…








Nadim

geolab

As per Workshop Manual
-Warm up engine to operating temperature
(80 .C to 90 .C oil temperature).
Use oil temperature tester (Special Tool
9122 + 9122/2) to check temperature.
- The oil pressure at idle speed must remain
between 2.0 and 2.5 bar. Have a second
person raise the engine speed to 2,500 rpm.
Read off oil pressure on tester. The reading
must be above 5 bar.

If you followed the proceedure , with the VAG and MAX pressure pegs to 4 or 4.5 only, then next step is the pressure release valves as you were advised. yes

os993

Hello Nadim, what does your shop say? Do they agree that the noise is too loud or are they saying it's normal?

Nadim Eid

Hi,
they need to listen to it personally. It is 5 hours away, so I will rather solve it by myself, if it is possible. Also, the car stays there ushually very long, as they do not have time. Left bank is signuficantly louder, then the right one.
Nadim