choc545

Looking for some help here. My oil pressure sensor is leaking. The prior owner had it replaced at the dealer at 74k miles, 78k miles and 84k miles all for leaking. I've got 96k on the car and it's been leaking ever since i picked it up with 94k. Obviously there is a problem. I'm going to tackle replacing it again this weekend and was wondering if it would be worth using some Permatex 82180 Ultra Black Maximum Oil Reesistant RTV silicone gasket maker. I was thinking I'd put a little on the threads, some around the washer and then install.

Anybody think this would cause an issue? Anyone tried it? Obviously it's going to be difficult to remove the silicone from the threads if I ever need to down the road but other then that I can't see any downside.

I appreciate your thoughts.

Thanks,
Paul
'04 545 w/6spd, 96,000miles.

Wolrab

Can you tell if it's leaking through the body of the switch, or it's the sealing ring that's leaking? With 4 failures in quick succession, I'd suspect that it's not the oil pressure switch itself, but something to do with the surface the seal ring seats on. The thread doesn't make a seal, so that's not in the picture. I would take it off and look very closely at the surface where it seals. Maybe it got damaged the first time they replaced the switch, or there's a blob of hardened something stopping the ring from sealing properly. Possibly they tried gasket maker before, and didn't clean it off properly. I'm not a big believer in gasket maker.

Mine leaked at 110k and again at 162k, which is not great, but I think it's considered about normal. Tolerable, anyway.

RTR

+1, check the surface.
And I think it usually leaks through the body, not through the sealing ring. Also was in torqued to the proper specs?

545iMike

Are you 100% sure its the switch or could your vacuum pump be leaking. Pump is right above the switch and its common for the pump to leak.

mfrasca

Rtv is definitely not the fix! If one little drop of that was to get into the wrong place, it could be catastrophic. Are you sure it's not the upper timing cover?

choc545

Thanks for the responses. I hadn't thought it could leak through the body of the switch. I just assumed it was the sealing ring. I'll be sure to clean everything around where the sealing ring meets the timing cover. I'm pretty sure it's not the vacuum pump as that was replaced at 60k miles 2.5 years ago.

Net, net it doesn't sound like RTV is reccomended. Thanks for your thoughts. I'll tackle this weekend and post a follow up on what I found after really digging into it.

Thank!

choc545

Update: so I cleaned off the vacuum pump, oil pressure sensor and everything around it last night with brake cleaner. I let it sit all night and this morning found oil underneath the vacuum pump near the front of it. So the vacuum pump is the issue and not the sensor. I'm guessing the dealer couldn't figure this out and that's why they kept replacing the oil pressure sensor. A new pump is $350 so I did some digging and it turns out there is an inner seal that goes bad creating the leak. The seal is different then the one that goes between the pump and the upper timing cover. Www.realoem.com site only shows one o-ring but the link below has both for $18. The good news is you can rebuild your pump for $18 rather then buy a new one for $350.

http://www.bmpdesign.com/product-exe...earch_model/92

545iMike

Can't believe the vacuum pump only lasted 2 1/2 years.