how long can an engine sit before its too long? with and without ATF or MMO. and after it has reached the point of being too long, how long does the engine usually last before it needs a rebuild? just curious, and i know it depends on the circumstances but you get the idea of what im wanting to know. thanks

 

My engine sat for 5 years in my car that was just parked in the driveway.

I unsiezed it (then consequently wrote my article on how I did it) and I've put 12,000km on it since. No problems, but it doesn't have all the power of a new engine of course.

My OMP is working so I don't think I'll be needing a rebuild anytime soon. I don't drive it light either (the shift buzzer is your friend).

As for "how long is too long?", well if you prep the engine properly, it can sit a long time. People commonly let engines sit for the 6months of winter. You just have to put a tablespoon or two of oil into each chamber and crank it through. That'll keep it lubed enough to turn later on.

Why do you ask?

Jon

 

i was just curious and i am about to purchase an rx7 with 68k original miles and lots of goodies installed. it sat for a few years though and when they started it up they didnt use ATF or MMO. it doesnt smoke and it runs good(has side draft, RB exhaust and many other mods). i also tested the compression and it was around 90-100. i am getting a good deal, it just needs some body work, but i was also just wanting to know. i also heard that it can be bad to have ATF in the engine for too long, something about the o rings?

 

If atf was that bad for o-rings, all of our ps pumps would be leaking long ago.

 

The car I'm currently driving sat from 1994 or so until 2 years ago. It needed the ATF trick to get it started but it has run extremely well since. It even passed inspection in its first year with no changes except for an air filter, plugs and plug wires. The only thing that suffers from being dry so long are those darn O rings at the top of the housings. They dry out and then leak when they see that 100 psi of oil pressure again and nothing short of a rebuild can reliably stop the leaking. To answer the question directly....that engine sat for at least 8 years before I towed the car home.

 

Are they both made of the same material or are you just giving advice based on your ASSUMPTION?

As for the original question: My '80 sat in the desert for 9 years before I got it about
3 years ago. The motor wasn't actually seized, so after swapping carbs, flushing the fuel system, an oil change and squirting a bit of oil in the spark plug holes, I rope-towed it down the street about 15mph with my '78 Courier and it started right up. Still driving it, and it's got 176,000 miles on the original motor.

So the answer is: how long a motor can sit is highly variable and depends on a number of factors, not the least of which is the question of "how good is your karma?"

 

I've had my 80 GS for 22 years now, yeah I'm an old fart, you know thats what your thinking :-). Until this past summer it had been up on jackstands since about 1998 or so. It had developed bad rear axle bearings and I didn't have time then to get into it.

In the first 4 years I made sure to start the engine a couple of times a year and keep gas stablizer in it. Later I got lazy and didn't start it for a couple of years and let the gas go bad. I also had started working on the bushings, bearings suspension and brakes so I couldn't really roll it out and start it. Plus the battery died.

Needless to say, I had a mess to clean up. The tank had crap in it which I had to take out. Had to change all the filters. Rebuild the carburator. Once I got everything sorted, it started up just fine, no smoke or problems at all. I'm probably lucky, but the car wasn't abused very much so it had a better chance than some others might. The first to time I started it I did put some 30 weight into each spark plug hole, rotate the engine by hand a bit and also sprayed some wd40 into the carb when it first started just to make sure everything was lubed real good after not running for awhile. I think that helped.

BTW, my car has 96,000 on it and during that 7 or 8 years only saw ~100 new miles. So you could say the engine sat fairly idle for awhile. I think it all depends how the car was put away and how its treated when you fire it back up. I personally wouldn't resort to the ATF trick unless it was seized up. Oil usually does the trick and is safer.

 

WG...does the engine have the dreaded "dowel pin" oil leak now that you've got it running?

 

I'm not sure how long would be too long. I think mine sat for eleven years total, nine before I bought it and two after I bought it. I put on a starter, ignition coils, spark plugs, spark wires, fuel pump, and filter and it cranked. I fear it wasn't too healthy though, it started up after a few tries too.

I'll tell you what though, all the white smoke made the yard a lot less populated with airborne insects. I still don't think the endless white smoke was a good sign though...

****, I made myself nervous.

 

It didn't until you mentioned it.

 

Ooops...

 

Mine sat for two years with bad gas in the middle of the desert. I will be the first to admit, it wasn't happy to start, but I got it there, and after a new carb, and some fine tuning, it ran fine. I dumped MMO into the carb whilst getting it started, though.

 

That is hilarious man, you made my day...