zigzag240 Posted May 5, 2007 Share Posted May 5, 2007 I have a F54 with P90 and SUs that I spent several months rebuilding and dropped it in last week. I have 250 miles on the motor now it and it runs perfectly. Oil pressure is 15-65psi, compression is great, the engine is solid with no leaks or noises. Pulls hard and starts perfectly. Today I just gave it it's first oil change and found that oil filter was empty, and appeared to have only the oil I poured in to prime it (!) What could cause the oil to bypass the filter like this? The way the oil passages run I thought the oil had to pass through the oil filter first. Since I'm getting great oil pressure this one is really baffling me. Could it just me a bad oil filter? Quote Link to comment Share on other sites More sharing options...
TBK Posted May 5, 2007 Share Posted May 5, 2007 This is just a WAG but what about the gasket that goes between the sump and block! If I remeber right it wasnt included in my engine gasket kit and I had to make one! Maybe it is sucking air into the filter????? but wouldnt think you would have pressure unless its air pressure???? Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted May 5, 2007 Share Posted May 5, 2007 How do you know it was the same oil you primed the filter with? Was there a different color between the pan oil and the filter oil? Check the little ball bearing next to the filter threads on the block see if it pushes in and rolls. Maybe the oil is going through the filter but it drained back to the pan so it seems like it was empty. does the engine have 15 psi at idle? Are you using a hi volume turbo pump? If the answers to those questions are yes then that seems fine... if you dont have a turbo pump then 15psi is a little high for the N/A pump, my psi is about 7 at idle (7 psi is just a guess, the needle hovers a little above the 0 just like every Z ever made) But then again it sort of depends on your oil viscosity is it 15psi cold or hot, are you running 30 or 10/40 weight? Hope that helped Matt- Quote Link to comment Share on other sites More sharing options...
zigzag240 Posted May 5, 2007 Author Share Posted May 5, 2007 All the gaskets are fine, so I just changed the oil/filter and ran it a while, and shut down. When I unscrewed the new filter it began to really drip new oil, so the new filter appear to be filling ok now. The only thing I can think of is the filter's relief valve was leaking and allowed most of the oil to drain back into the block, and the filter looked empty. I'm using a turbo pump and it really seems to be putting out the presssure. My scare for the week, thanks for the tips. -B Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted May 9, 2007 Share Posted May 9, 2007 The only thing I can think of is the filter's relief valve was leaking and allowed most of the oil to drain back into the block, and the filter looked empty. -B Sorry but I saw this and a light went on. If I haven't started my Z for a few hours it will take a FEW SECONDS to build up any oil pressure. I just figured the bottom end was worn out a bit. Hmmmm. Quote Link to comment Share on other sites More sharing options...
johnc Posted May 9, 2007 Share Posted May 9, 2007 NAPA Gold 1515R. Quote Link to comment Share on other sites More sharing options...
SHADY280 Posted May 10, 2007 Share Posted May 10, 2007 ^ oil filter that doesnt drain??? Quote Link to comment Share on other sites More sharing options...
jeffp Posted May 11, 2007 Share Posted May 11, 2007 John mentioned a filter and I guess that is a good unit. The thing about the Nissan oil filters is that not all of the filters have the flapper/sealer in the filter. That little flapper gasket seals the outlet of the filter when the oil pressure is not up. This maintaines the oil in the filter, so you don't have to prime the filter for each start up. What eill happen with the incorrect filter is that every time you start the car, you wil see a delay in the oil pressure coming up. So check the filter. Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted July 29, 2007 Share Posted July 29, 2007 So is this valve/flap something I could see if I had a filter in my hand? Can you get a NAPA filter anywhere or just from NAPA? What other filters will work (right)? Quote Link to comment Share on other sites More sharing options...
nbesheer Posted July 30, 2007 Share Posted July 30, 2007 When I bought my K&N it said it has one of those valves and still when I start the car up I don't have pressure but I get pressure a lot sooner then with my nissan filter I had on there before. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 1, 2007 Share Posted August 1, 2007 Yes, the flapper JeffP is mentioning is referred to in the Oil Filter Business as an 'Anti Drainback Valve' and functions exactly as JeffP says: holds the filter full so you have no 'accumulator to fill' before building pressure int he system. The Nissan Filters do have an Anti-Drainback Valve, some premium filters boast of 'silicone anti-drainback valves' which seal more positively and tend to not harden in the heat inherent in the oil system. Not all filters that 'fit' are proper as designed. Many industrial filters do NOT have the drainback valve in them as for remote field servicing they don't want oil held in the filter to drain all over the equipment. An Atlas Copco GA160 Air Compressor has three spin on filters that go threaded side DOWN...if you had an anti-drainback in there, a gallon and a half of oil (hot, searing Air Compressor Oil, 215 degrees F) would be waiting to shower your groin area as you spun them off! But on a Nissan L, you want an Antidrainback valve, for the aformentioned reasons. Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted August 1, 2007 Share Posted August 1, 2007 So is the flapper the rubber-like part that covers the holes around the center (screw on) part of the filter? I know in another thread someone was saying that the ones with orange silicone flappers are better than black because the black will harden. I bought a Mobil 1 filter at walmart and it has a visible large spring in it (hopefully not the low pressure bypass valve) and an orange seal of sorts behind the holes. Fram tough guard did not have the spring (visible) and their piece was black. Sooo, I wanted to know before I put the filter on the car and got no benefit from it. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 2, 2007 Share Posted August 2, 2007 Springs are usually internal bypasses to keep the filter element from collapsing under some flow conditions (idiots that rev their engines cold comes immediately to mind) chances are good the 'orange thing' you see is indeed a silicone anti-drainback valve. There should be a manufacturers website you can directly reference for information on wether there is an anti-drainback valve or not. I got into researching some of this when I worked at a filter supply company---there are some air compressor filters with about 2X the filter media capacity (and better micronic filtration rating), and similar bypass valve arrangements, but alas they didn't have the anti-drainback valve---and that is important when the filter contains almost 2.5 QUARTS of oil, mounted to the side of a block. For remotes with the screw on portions pointing up it's not a big deal, but I didn't feel like adding remotes to my car at this time... Quote Link to comment Share on other sites More sharing options...
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