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Oil pressure


boxboy

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So I changed my oil a while back with a filter that was new, but was in my truck when I bought it a year ago. Napa filter. I had used a new Napa filter the last oil change and didn't notice any issues. But since the latest change I have noticed that it has taken a few seconds (3-4) to build up oil pressure. First I thought it might be because I have been using 20-50 upon recommendation that older engines like it. So I drained the 20-50 and put in 10-40. No difference. So after reading a few posts on here about filters that have bad one way valves, I decided to swap it out for a new one. I got all ready for oil to come gushing out the filter as it typically does since the filter is for some reason designed mouth down:angry: Anyway, unscrewed the thing and there is nice clean 10-40 in the housing, but nothing came out of the filter! I am assuming it is the filter's one-way valve failing. What filters do you all use? Ever had this issue?

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NAPA gold are good, expect to spend about $6 for a good filter. Avoid Fram, back in the 60s they were premium filters but the company that owned them and the name has been sold and passed around like a 15 year old at a biker meet. They are sold on the reputation of their once good name but the quality of materials is very poor.

 

Replace the filter for sure and the oil is optional.

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I did not know that filters have a valve in them, I still don't think they do, on some datsun oil filter housings/mount pedistals on the block there is a tube that sticks up out of the center, that tube goes almost all the way to the top of the filter on the inside, it's funtion is to keep the filter full of oil, if the tube is removed the oil drains back out, now I am not saying that this is what is happening to you, I am just throwing it out there. It sounds like your filter is draining when the engine is off, and is having to refill upon starting. My datsun roadster had/has this center tube. wayno

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Some filters advertise an 'anti drain back valve'.

 

I've seen these tubes Wayno, they aren't in all motors. It screws into the block and replaces the threaded fitting there. The base of the tube has the threads that holds the filter on. Would work best in vertical mount filters.

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Hmm? Now you have me wondering Wayne. Mine has a tube that is most of the way up the filter, yes. But apparently it is not keeping the oil from draining back out when the engine is not running. I agree with your diagnosis. Could there be another explanation other than the filter having issues? If I have oil pressure (I don't know how much, but enough to get it to the top end and turn of the idiot light), then I am assuming that oil is circulating and filling the filter when it is running. But the fact that the filter was empty when I removed it means its going somewhere. Where is the question. I just did this today, so tomorrow when I cold start I will see how long it takes to build pressure. As far as whether it has a "valve" or not, I don't know. Just read it in some post on here a while ago.

 

This is part of the reason I would like to have a oil pressure gauge. I need some time off so I can get to a yard and find a set up out of a 720 and hook it up.

 

Mike, this is a J13, so it is a vertical mount. The tube I have is as you described with threads at the bottom to hold the filter on.

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Wayne, here are a couple of sites that list the filter for WIX and NAPA filters for the J13. Both mention that they have an "anti drain back valve".

 

http://www.wixfilters.com/filterlookup/PartDetail.asp?Part=51512

 

http://www.napafilters.com/filterlookup/PartDetail.asp?Part=1512

 

. . . so the must exist! I am using the Napa ones. I assume that the one I used that had been sitting for a while in a non-temperature regulated garage, and who knows how long on the floorboard of my truck simply had a stuck or non functioning valve. I replaced it with a new one.

 

Now, I started the truck again yesterday after 30 hours of not being driven and it seemed to take a second or two for the light to go out, but I may be hypersensitive to it at this point. I am not sure what else could be the reason oil is draining out of the filter. I guess oil could be not getting into the filter in the first place, but then I would think my oil pressure light wouldn't go out at all, and I can see oil oozing out the rockers through the filler cap, so I am pretty sure the pump is working. I will keep watching it.

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I started the truck tonight and got a couple (2) consecutive knocking sounds then oil pressure built up and nothing strange after that. Subsequent start ups (3) at 1 hour intervals and all was normal. Instant oil pressure and smooth starts. Am I worrying too much? What are the knocks all about?

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I started the truck tonight and got a couple (2) consecutive knocking sounds then oil pressure built up and nothing strange after that. Subsequent start ups (3) at 1 hour intervals and all was normal. Instant oil pressure and smooth starts. Am I worrying too much? What are the knocks all about?

 

Maybe you are worrying about it to much, do you think the sound is a rod knock? My valves make a little clicking on start up. What viscosity oil are you using?

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It sounded like a rod to me, but I haven't ever had one go bad before. Definitely not the valve train. I know that sound. Like I said, once it was up to pressure I heard nothing and didn't on subsequent starts. I am using 15 40. I had been using 20 50 before regasketing.

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It sounded like a rod to me, but I haven't ever had one go bad before. Definitely not the valve train. I know that sound. Like I said, once it was up to pressure I heard nothing and didn't on subsequent starts. I am using 15 40. I had been using 20 50 before regasketing.

 

In the past I had an engine that had a slight rod knock, it could be heard on cold start, then it would go away, but it could also be heard after it was warmed up. I use 20-50 on everything.

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