I just bought a 83 280zx 2+2 t-tops, digital dash for $500...definitely not a daily driver ...at least not yet...however, I let my mechanic take a look at it and in his opinion, the car has a bad engine....When you crank it up, it smokes for about 3-5 mins or less but its a lot of smoke....after the car warms up, it doesn't smoke anymore...driving down the road after it warms and the car doesn't smoke....the engine has 223k miles on it and the car was sitting for over a year or so; little rust, crappy seats...but all in all im happy to get it sooooo cheap...I hate to get rid of it...I wasn't expecting to have to replace the engine so soon...Does anyone have any ideas/alternatives....Can't i use Smoke-B-Gone or something...LOL...?!?!?! My mechanic did suggest a used engine for like $1600 parts labor...but to be frank im not interested in that at all...I could just buy one for that!!! Any feedback would be appreciated...Thanks in advance...Im new to this site and z-cars....Help.

 

Check it with a compression test and a leak down test before considering the motor toast. It may just be all the leftover stuff inside the motor from sitting for so long.

 

1600 for a used engine? LOL do it yourself. its easy and you can get a nicely built motor for well under a grand. sounds like you got some static dynamic compression issues. aka when the car warms up and everything expands the compression ups cause the rings seal better. hence no more oil blowing past and burning. there for it no longer smokes. do you know what the compression is in all the cylinders?

 

Welcome to ZDriver! What color is the smoke?

 

thanks for all the help...the smoke is really white and really isn't blue, ya know so honestly i really can't say...I asked my mechanic about the compression test however he said he doesn't feel thats the issue...(he works on these cars alot...) said he was going to check something with a transmission hose that could be leaking into...the engine...(uh...yeah...) ...and causing the smoke...but again in his opinion compression isn't the issue...but I will ask him to do one just so i know the numbers

 

"When the car warms up and everything expands the compression ups cause the rings seal better ....." ....is exactly the first thing he explained to me...

 

Smoke:

White = burning coolant
Black = burning too rich
Blue = burning oil

Have you looked at your oil dipstick? Is the oil foamy? You may have a warped head / leaking headgasket. You can also pull the spark plugs & check the tips (do this before the smoke is gone when warming up).

 

k, will do Nismo. Have you ever heard anything about the transmission fluid causing the car to smoke like that? The seller told me that the trans may have a leak but it doesn't slip or make strange noises...and i haven't noticed any puddles on the ground underneath it...Could this potentially be my problem?

 

Actually... yes. Auto transmissions have a vac line connected to the back of the intake manifold (by the vac line for the brake booster). If for some reason it's sucking ATF into the intake, it will burn white smoke.

How do I know this? Well... I bought a 4Runner last fall, power steering didn't work. Turns out the previous owner hooked up the vac lines to the intake wrong... I added some ATF to the reservoir and POOF! Lots of white smoke as it sucked all the ATF into the intake.

 

...and the smoke is more White than Blue-ish ...im at least sure about that which made me comfortable buying the car...and like i said, the trans fluid has been staying low. I saw the car one weekend and the seller and I put a quart or less in it...and came back 7 days later to pick it up and put a whole bottle of Lucas Trans Condition in it....allow me to mention I drove the car 250 miles to get it home...it didn't run hot and the temp remained the same...

Since Im getting such great help allow me to ask one more question...Some one rigged my fusible link...when the fuse blows, the digi dash goes out along with my tail lights and my alternator does not charge my battery...besides rigging it with a 30 fuse, can i purchase a new fusible link or can i get one from the junk yard...? what years work?

 

So they popped in a 30amp fuse? Easiest thing to do would be to find one at a junk yard & swap it in. or you could upgrade the wiring w/ your own... it's up to you.

How about posting an up close pic of the fuse links?

 

If you're losing that much ATF, it sounds like your modulator valve for the transmission is bad. It's located on the driver's side of the transmission right above the small heat shield that attaches to the front of the transmission oil pan. Replace the vacuum line that's down there as well when you change the modulator out. If you're blowing the 30 amp, maybe you have a + wire shorting itself out somewhere?

 

I will take some pics of the fuse links when i go see the car tomorrow...again thanks for all the help...Maybe I'm in denial but I'm not convinced the engine is bad.

 

That's good... when you've got a problem, just keep narrowing it down until you find the cause. Then weigh the possible solutions. Welcome to owning a Z!

 

If you drove the car 250 miles, it still has coolant in the radiator, didn't run hot, and you still have oil that isn't milky, I'm going to say your engine probably isn't bad. I could be wrong, but that doesn't seem like the issue. How does the car run? Or even when cold and it's smoking how does the car run? I think it's odd that the mechanic doesn't want to take about 5-10 minutes to run a compression test on the vehicle. It doesn't really seem possible that the engine would be in such a shape that the compression would be causing you all kinds of problems when cold, then warm up and seal enough that it has no problems. I could be wrong though.

Also, when you check the tranny fluid are you checking it while warm or cold? You need to check it after the car has been warmed up to get an accurate reading, as most of the time if you check it cold it'll appear low.

 

magbe i'm missing something, but this is winter, and all cars, even if they are rolling off of the nissan assembly line after 17.5 hours of building, if they are cold and have been run before, will steam out of the exhaust. it's the condensation that forms in the pipe when it goes from near 1000 degrees to the ambient outside temperature. if your only quarel with the engine is white smoke on start up, then i wouldn't be the least bit worried about the engine.

 

I forgot to add that into my reply. Yeah especially if the car is sitting there idling the pipe takes longer to heat up and burn off all the condensation then if you're actually driving.

Like I said I think it's odd that you mentioned nothing about driveability issues, drove it 250 miles to bring it home, and the mechanic just says you need a new engine while saying he knows that he doesn't need to do a compression test.

If you want do a compression test yourself, you can either buy a tester or I believe rent one. All you gotta do is pull the plugs put the tester in each plug hole, preferably the screw in type, then crank the engine for about 6 seconds. Get out check the reading, write it down, repeat. It's super easy doesn't take long, and then you'll know for sure. Personally even if the guy does a compression test, unless you're there to see the results of each cylinder, I'd be weary of what the mechanic tells you since he seems so eager to get you a new engine.

 

to expand on that, not just 6 seconds, but exactly 4 revolutions for best results.

 

ONLY the screw in type. disconnect the AFM so the fuel pump doesnt work and hold full throttle and crank the car. it will only give one number so it doesnt really have much to do with time/amount of cranking. do a compression test, it is the end all be all of motor rebuilds.... mostly. other than a knock and other stranger internal engine problems. but in this instance.

 

what do you mean only one number? mine goes up with every revolution. after a few it levels off and stops going up, but if you don't do 4 rev's it might give a low reading. i can confidently say that with my guage, you need 4 revolutions. and it's no piece of crap or old or anything

 

thats what im saying, whether its 4 revolutions or 100 its only going to go up to one number. obviously it wont cpature the proper reading on one revolution

 

oh ok. i thought you said any number of revolutions would give the same number

 

My 280 had been sitting at a salvage yard for quite a bit of time w/o being started. It took quite a bit of time to start her the first time, and she smoked like a freight train (blue smoke) for about 5 minutes. The next time I cold started her (the next day after I took her home...$500, heck yeah!) the smoke lasted for 2-3 minutes. A couple more rounds of 30-45 second smoking, and it has now stopped, even on the coldest day. If it had not...well, I would have most definitely rebuilt the engine. That's part of the fun of owning one of these cars...playing around with them. If you are not prepared to take the time to learn how to work on them and do the work, then you should probably consider another vehicle. If you are, then you will have a lot of fun!

Chris

 

Most definately. These engines are easy to work on and learn. It takes time, but anyone can pretty much work on one of these cars given the right resources. (like Zdriver! Thanks).