I'm wondering how long the average L28 engine in a 280Z will last, miles wise? I know every engine will be different and of course taken into account all the infinite number of variables, but from experience?

I currently have my L28 out of my Z and I'm cleaning it up and going to replace the necessities. However deep in my heart I really want to rip it apart and give it a complete rebuild. It has 177,000 miles on it, I've never seen it run since I bought the car after 8 years of sitting and went straight into giving the engine bay a refreshment. The PO said it ran fine when he stopped driving it.

Anyhow I just want to know because if it will easily make it to 250K then maybe I should just wait it out, if not maybe I should follow my heart and go right on in?

Thanks guys.

Mine has about your mileage on the original build. It has very good compression and seems solid. It doesn't burn oil. It might have pulled an additional inch of vacuum when new, but I can live with that. I find this a bit miraculous because when I bought the car, the engine innards looked like the inside of a BBQ grill. The sludge was polymerized and abbrasive. Even so, it seems no damage was done. I have no reason to do a rebuild.

I suspect 250k with reasonable care isn't out of the ordinary.

Of course it would be nice would be to mill the head a bit to increase the compression ratio, but I'm not going to pull the head just for that.

But that's just me. If you want to rebuild and can afford to do it... Go for it!

250K it is just getting broken in.

Fastwoman nails it. L engines will live through an astonishing number of miles before requiring major work. Having said that, since you have it out of the car already, it certainly wouldn't hurt anything to give it a look-see and refresh those parts showing a bit of wear.

The head is usually the first thing that needs work (can anyone spell valve seals??), well before the block, which is very very strong and long lasting. A compression test and leak off test will tell many tales. If you put most of those miles on, and did proper timely maintenance throughout, its got a long life yet.

If you just can't resist, refresh the head and leave the bottom end alone.

When I bought my 78 it only had 42000 miles on it. I had been parked for 3 years because of a bad rocker, at least that's what the PO thought. It turned out that the nut had backed off and the rocker wasn't on the valve. Even so, I pulled the head and freshened it up, valve job, seals, etc. When I sold it a couple of years ago it only had 98000 miles. Because of that, my car likely had that 'additional inch of vacuum' that Sarah spoke of which is, IMO, the main reason that I didn't have many of the EFI problems that I see people trying to chase down here and the reason why it never faied a smog test. And it still hasn't, not even with the new owner. The 'tightness' of the engine is probably more on the EFI cars since there are no real adjustments you can do to compensate for low vacuum, compression, blow by, etc.

Edited July 27, 201113 yr by sblake01

The 'tightness' of the engine is probably more on the EFI cars since there are no real adjustments you can do to compensate for low vacuum, compression, blow by, etc.

That should have read: The 'tightness' of the engine is probably more important on the EFI............

Well that is good to hear, and I have heard all along that these engines will take a heavy beating!

I really want to rebuild it just so the engine will be better then new, but then again I really want to rip the entire car apart and rebuild every little thing and make it perfect.. College, time and money are a bit of a road block right now however.

Guess I'll just clean her up well, replace the necessities and let her sip on some atf when I get her running.

Thanks a bunch for the help, the people on this forum never cease to amaze me!

My 79 280 ZX (I'm original owner) has 215,000 miles. The head has never been off. I did a compression test 10 years ago and everything checked out. Over the last 10 years I've done 2 track days per year - really pushing it to the limit and it still runs great. Engine oil has always been changed before each track event so it probably never goes more than a 1000 miles betrween oil changes. I also keep the valves properly adjusted. It also has rhe original fuel injectors. I run a can of BG44K through it once a year.

Good maintenance begets longevity.

It's really only living when it's pushing 4500 RPM's or more and a cool breeze it's running over it's metal skin! Drive Fast My Friend!

My mom had a 810 maxima (same basic engine just 2.4 liters) and at 450,000 miles the head gasket blew. That was in 1993. My stepdad pulled the head, cleaned everything reinstalled with a new head gasket and my sister in law still drives this car to this day. Probably has close to 750,000 now...

Mine (125,000 miles) is knocking lightly for a few seconds when you start it, so I think that the main bearings might be a little worn, right?

Other than that, I change the oil every 1000 miles (or every spring) and keep everything clean, and the EFI/electrical connections cleaned with DeOxit, so the engine runs just fine. I will probably refresh the engine over the winter in the next few years.