removing oil pump Options

[dmenche914]

i got some good replies to my prior question about how to best remove the oil pump (engine out of car) I am not rebuilding the engine now, just want to check the pump as pressure was a tad bit low when hot.

It was suggested that I might have to loosen the case half bolts to get the pump out.

Will I run into problems with case half leaks if I need to do this?

Isn't the case halves sealed with "glue" to prevent leaks, and if I seperate the halves even slightly, I would need to re-apply sealant?

How can I reapply sealant to the halves If I do not fully split them, and clean them up? Remember, I am only pulling the oil pump, do not plan to work ont he bottom end of the engine at all.

thanks dave

[ArtechnikA]

...just want to check the pump as pressure was a tad bit low when hot.

first, been a long time since i've done a /4, and never done a T-IV oil pump (several T-I and T-III's tho...) since you're not getting a lot of responses i'll try to help tho.

first - what do you propose to 'check' by removing the pump ? i can't imagine.

you may wish to remove the COVER and check for excessive wear in the cover, and you can check the backlash in the gears. but i don't think there's anything to be gained (and many potential issues) by removing the pump body. removing the cover is NBD.

i have seen little turnbuckle thingies that press (GENTLY!) against the mounting studs to relieve the clamping pressure for removal. you're not looking to part the case, or crack the case sealant - only slightly relieve the clamping pressure, and that -should- be enough for you to draw the pump out - i think i've seen some gearpuller-like tools that straddle the opening and allow you to use screw pressure to pull the case.

that said, the number one cause of low oil pressure symptoms is bad senders, bad gauges, bad wiring between the two, and bad grounds at either end. (IOW - instrumentation, not oil pressure at all.) after that is rod bearing issues - but most all Porsche engines run fairly low hot idle oil pressure, especially on too-thin oil.

[JWest]

Rich, you can't just remove the cover on a stock T-4 oil pump - basically it is assembled backwards from a T-1 style pump and what you see on the outside is the part that goes into the case. Once the pump is out you can take it apart from the inside.

Dave, I really don't think you have a problem, though. I saw the other thread and you said you have 35 - 40 psi at 3K RPM, correct? Conventional wisdom says that betwen 10 psi and 1 bar (14.5psi) per 1K RPM is good pressure (applies to most engines). The oil pump is usually the last thing to wear out in these engines, so I don't think you have anything to worry about, nor will find anything wrong with your pump.

But, if it will give you more confidence then go for it. I think the case seal will not break ifyou just loosen those front bolts enough to relieve some pressure.

[ArtechnikA]

Rich, you can't just remove the cover on a stock T-4 oil pump - basically it is assembled backwards from a T-1...

i keep forgetting that! thanks for pointing out the error of my ways.
i'll go chant "i don't do /4's" another thousand times ...