Hi all, I'm a noob to this site, happy to join up! I've got a weird question that shouldn't happen...

So I just bought a Sunrader RV, it's on a 1984 Nissan/Datsun 720 pickup dually cab and chassis with the Z24 carbureted engine. A great running engine and vehicle, love it so far! I went today to change the oil and filter for the first time, and strange stuff happened. Went to my local Autozone, then to O'Reilly's, then to the RockAuto website, no matter where I go you see what looks like a bunch of inconsistent filters specified, and they don't look like they're interchangeable, and for the most part don't look like they even fit. All these places specify a Fram PH8A, or various brand versions of it, which is a big fat filter, they're all about 5" tall and nearly 4" (3.66") in diameter. But they also specify a Fram PH3682 and a bunch of other brand versions of that filter, which is just under 3" diameter and 4" tall. There's like choices of six or eight filters by brand in each of these two basic sizes. Dang, that PH8A fits my F-150 engine if I remember correctly!

The filter that's currently on the engine is the small size, looks like 3" diameter and 4" tall, a Carquest, can't see the number on it. However, the shape of the engine block where the filter screws on looks too small for a 4" diameter filter, so I'm also doubting the PH8A for that reason. I have a separate problem, the current filter is on so tight and hard to reach it looks like I'm gonna have to take out the alternator to make space for a filter wrench that won't crush the thing on the engine.

SOOO, I'd love a little feedback as to what filter other folks with the 84 Z24 engine are using? Is there a chance the current filter is stuck cuz it's the wrong one?? Am I gonna learn that the gasket seal is the same diameter on all these filters (they sure don't look it in the pics)??

Thanks!

Welcome to NICO! Have you got some photos of your camper?

That is quite the conundrum!
You've done a ton of research, hopefully someone can chime in with what they use.
In the meantime, I'd be getting that old one off and then buying 4-6 of those potential filters to see if any of them work and make sense.
For really stuck filters, I like to use those plastic jar openers. They're compact and fit most any where and let you apply a butt ton of torque.


Let us know what you ended up doing!

Ph16 *was* the correct filter for that engine. Fram changed their filter. The new one fits but its a little smaller. It should be a PH3682.

Don't sweat the external dimensions - all that matters is the mount. For example, I'll usually compare oil filters at the store, and select one with the same diameter threads and gasket surface, but a bigger "body" - more capacity is always good.

You can use ANY of the following list (which is probably where the confusion comes from) - Check it out:

http://www.oilfilter-crossreference.com ... ram/PH3682

Welcome aboard!

Hi guys, thanks so much for the replies. Confusion cleared up! I've had to divert for a few days for some health issues in the family, but I'm gonna get on the truck this week. (I'll try to figure out posting a pic to the forum, also)

The engine is original, has 120K on it, runs like an absolute top. I'm *very* impressed with this drive train, it's every bit as good if not better than the famous Toyota R22 of the same age. I drove the rig from Casper, Wyoming down to Austin, TX when I bought it a couple of months ago, and have done a 2500 mile road trip since, the engine is using a quart of oil every 2500-2700 miles, so it's in great shape. The whole rig is showing deferred maintenance that I'll be getting after, *all* of the fluids everywhere in the vehicle (clutch, brakes, antifreeze, power steering, tranny, differential) need changing/replacing, they're all really dirty. Engine oil was clean on purchase, but it's ready now. I'm thinking of using one of the extended life filters, Amsoil, Mobil 1, or similar, and putting in full synthetic from here on out. I'll probably have the oil tested once or twice as the miles add up, but I'm thinking I should be able to go up to 10,000 mile change intervals. I have a VW Jetta turbodiesel, which can only use full synthetic on a 10k change interval, it's really convinced me of the value of synthetic oil for engine life (I have 480k on that diesel and it's running strong as ever). Anybody have any problems with seals in the Z24 when they did that?

I'm also at some point gonna have to get at a leak at the rear of the 5-speed tranny, from underneath it looks like it might be coming out at the top opening for the shifter, I'm hoping I can get that seal out without dropping the tranny by opening up the shifter floor cover.

Thanks, I'm glad to see this forum is active, I'll be doing what I can to contribute.

Just my two cents, I use the smaller filter because it's easier to get in there. I think STP's is the biggest (fram and purolator are smaller) and it's a little harder to get under the intake manifold with all the hoses under there...

Yeah, the spaghetti is a mess on this engine. I guess the mid-80's, before they started using catalytic converters, saw a *lot* of vacuum lines for the beginnings of pollution control. But I found I could move some of the lines, including vacuum and power steering, around a little, I now have small path for a hand to reach in there and get at the filter.

I put on a Mobil 1 extended life filter, it's not too big, but I'm hoping to get 10k miles out of it along with Mobil 1 High Mileage full synthetic. I'm probably gonna get it tested at 7 or 8K to be sure.

I've got cooling system, brakes, and clutch fluids flushed and changed, new tires, lots of work on the interior. We've taken three trips, couple of weeks each, and put 6000 miles on it now, it is just a great running engine.