Chain Tensioner Relief Valve issues

[artwangler]

In Wayne's book 'Rebuild and modify' 911 engines, he mentions that the "pressure relief valve" on chain tensioners are know to fail. What is this 'common' failure? Does the valve stick 'closed' or stick 'open'? My tensioners allow oil to seep from the relief valves with little resistance.
I pushed oil into the tensioner to 'Bleed' air bubbles. However, one of my tensioners seems to easily allow oil to escape, the other tensioner requires more pressure for the 'relief valve' to open.
Should I be concerned about the pressure at which the 'pressure relief valves' open? Is my engine oil pressure suffering because the tensioners are allowing oil to escape easily? Or is that normal? What is the 'common failure of the pressure relief valve' that Wayne mentioned in his book?
I bought a replacement 'new oem' tensioner but it seems no better than my old tensioner. Are they both OK or are they both failing at the 'relief valve?"
Many thank to anyone who knows about 'relief valve' issues.

[Trackrash]

The relief valve on those tensioners is an enigma. I asked that question years ago and here is the thread. Carrera tensioner questions And a follow up. Tensioner failure >opinions?<

Bottom line is if the plunger, when you have the unit filled with oil, is not totally firm, Porsche says replace the tensioner. The problem is you didn't test the tensioner just after you opened up the motor.

[artwangler]

Hey, thanks for the reply.

my main plunger has plenty of resistance, enough to keep the timing chain tight. It is the 'pressure relief valve 'that 'weeps' oil out the top of the 'reserve' chamber. The idea is for the 'reserve' chamber to stay full of oil and be free of air, it does this by allow a steady flow of pressurized oil to escape at the top of the reserve oil chamber. My concern was raised when oil weeped easily from the 'pressure relief' valve on one tensioner, while that was modest resistance (or back pressure) with the other tensioner. It seemed that the tensioner that was 'weeping' excessively could lower my overall oil pressure, or lead to too much oil in the sump. But, when I purchased a brand new OEM tensioner, it also 'weeped' easily, under very little oil pressure that I created using a large syringe full of oil driven into the tension's oil inlet.

I'm trying to find out if anyone knows how much pressure it should require to open the 'pressure relief valve' of the 'reserve oil chamber'
Thanks for your contribution to my search.

[dannobee]

The common failure is that the "hat" holding in the spring and ball bearing comes out and the parts eventually find their way into the sump near the oil pump pickup. There are several thread here, with pics to show what to look for.

[Trackrash]

Originally Posted by artwangler

Hey, thanks for the reply.

my main plunger has plenty of resistance, enough to keep the timing chain tight. It is the 'pressure relief valve 'that 'weeps' oil out the top of the 'reserve' chamber. The idea is for the 'reserve' chamber to stay full of oil and be free of air, it does this by allow a steady flow of pressurized oil to escape at the top of the reserve oil chamber. My concern was raised when oil weeped easily from the 'pressure relief' valve on one tensioner, while that was modest resistance (or back pressure) with the other tensioner. It seemed that the tensioner that was 'weeping' excessively could lower my overall oil pressure, or lead to too much oil in the sump. But, when I purchased a brand new OEM tensioner, it also 'weeped' easily, under very little oil pressure that I created using a large syringe full of oil driven into the tension's oil inlet.

I'm trying to find out if anyone knows how much pressure it should require to open the 'pressure relief valve' of the 'reserve oil chamber'
Thanks for your contribution to my search.

I also thought it strange that about 10 psi would allow oil to weep out of the top check valve. That is the way it works, FWIW. I discovered that the inlet actually has a restriction, thus regulating the amount of oil going through. I agree, it doesn't make sense, but that is how they work.