njwilser

Well, as everyone seems to like the Mahle oil filters, I bought four of them on-line a while ago have been using them exclusively on my 85/1. Well a few months ago I was getting repeated low presssure starts for about 30 sec. to a minute.

So I changed out the oil and filter (w/ a mahle) and all was fine. Well the last couple of mornings, same damn thing. No pressure on the gauge, and clackety clack from the engine for thirty seconds or so, then pressure rises and pegs the gauge. Other than at start up, the car exhibits strong oil pressure.

BTW, I have 10/40 in for the winter and run 20/50 the rest of the year.

I assume this problem relates to the anti-drainback valve in the filter, and not the OPRV in the car??? Or the oil pump in the car as the last Mahle I pulled off the vehicle was actually empty.

Am I the only one disappointed in the Mahle anti-drainback valve???

I purchased an STP S6941 oil filter manufactured by Champion Labs, as I understand they are Porsche OEM also.

So for now I will try the STP filter, unless someone can shed some differrent light on this and explain why my mahle filters appear to be "draining back"

Thanks, Mike

Crunky

I get the same thing for about the first minute or so. I had been using a K&N oil filter for the last 3000 miles and 15-40, just changed the oil today and went with 10-40 and a Mahle filter, still same noise. I don't know why, but I'm hoping for an answer too....

AznDrgn

I'm probably gonna get flamed for this but I run either a Purolator filter or a Hastings filter in mine and I have pressure as soon as the engine cranks over. I would say you guys are definately having problems with anti drainback valves or else there is a leak in your oiling system allowing the system to un prime itself.

KuHL 951

I won't flame you, I use the Purolator One also...great filters when I can find them. I have had issues with a few of the new Mahle's also. They aren't all made in Germany anymore.

yellowline

The one on my car now came from Austria, I don't think that's too bad. I have no trouble with it.

CO951

Does the Purolator One had the anti-drainback valve?

AznDrgn

Yes

Jfrahm

I have used a lot of Purolator filters, they are great. Mahles have always been good for me also. 30-60 seconds seems longer than I would expect the filter's drainback to be an issue. It only takes a few seconds to get oil pressure after an oil change for me (5-10 sec.)

Stephenwz968

I've used the purolators and the mahle, does anyone have any experience with the STP filters? I can see a spring loaded valve in the bottom of it, but haven't ever used one.

njwilser

Stephen,

I agree and noticed the same thing that a new empty filter only takes a few seconds to fill and develop pressure. The only thing I think may cause this is that the air in the system passes thru a dry filter media quite rapidly, but when the filter is oil soaked and full of air, the system has a difficult time bleeding that air out of the system.

I searched a bit and found that user "lemming" experienced the same as I. I think that Mahle may have had a batch of filters where the nitrile drainback check valve was of poor quality and would develop a set after a while and wouldn't seat properly allowing the oil to drain back.

FYI, IMHO the STP S6941 is the exact same filter Porsche is selling over the counter as OEM w/ different paint. Available locally at Auto Zone for around 5 bucks.

In the future STP for me. Not impressed w/ the Mahle at all. Your mileage may vary. Thanks for the input guys!

Mike