So i've had my 87 for about 4.5 years. electrical issues here and there but nothing major. the last issue was resolved by cleaning the main chassis ground and the connections to the main fuse box in the engine bay a couple weeks ago. Car has been running great since... until now...

My brother borrowed my car for 3 days and yesterday morning I noticed it was out on the street instead of in the driveway or the front yard where it normally gets parked so I grabbed my keys and went to move it. Started with a flick of the wrist but EXTREMELY rough idle and with a new noise, rattling akin to shaking a bolt in a coffee can. After about 5 secs the engine died.

Last time I changed the oil my in dash meter was reading a little low, but still about 25 psi at idle and 40ish cruising speed, 2.5-3k rpm. Chalked it up to the lighter oil i put in last change.

From what I understand, the rough idle and dieing could be low compression but then it shouldn't start so easily if that were the case. what has me worried is the loud rattling sound along with the other problems. bearing or apex seal in the housing? any other suggestions or ways to confirm this without pulling the engine? last time I did a comp test, a little over a year ago, i was getting just over 90psi on the front rotor and just at 90 psi on the rear rotor. i'm going to do another one to check for seal failure but wanted to get some input in the meantime.

I had to move the car up into the yard so I don't have to try to work on it in the street. Adjusted the idle screw up a little and the car did stay running but still really rough. The tach was bouncing from 1k-1500rpm after the initial 3k warm-up. I was also able to get a better idea of where the rattling is coming from since I was actually able to run around the car while it was on. Sounds like it's coming from the CAT area so time to jack the sucker up and ensure everything there is tight.

I forgot to put this in the original post but the car is an 87 NA with 220k on the original completely stock engine/tranny.

tinkered with it a little more, throttle plates look pretty clean. Cat seems tight, as does the heat shield. Waiting to get my compression tester back from a friend now but I started it up for about 30-60 secs and let my dad run around the car listening for the rattling. He's an old redneck mechanic that kept our deputy's cars running for 30 years. He thinks it's coming from the rear rotor... disastrous... with the car idling at 1500 rpm, after i idled it up to get it moved, it sounds like 500 rpm so I'm inclined to agree with him until I can verify compression failure there. the false CAT area I assumed earlier today could have been due to the sound amplifying off the firewall and ground...hopefully I can get the compression test done today or early tomorrow.

thanks,
Jason

this a composite of a thread I have up on another forum, the more the merrier!!!, with a couple things updated. been on here for the entire 4.5 years since I bought the car and always use it as the first source of info when i've had a problem and i've never had to post because I've always found the answer!!!

 

Did my compression test. Rear rotor is gone, only one pulse on the meter. Front one still seems good but weak. I didn't want to warm the car up fearing that knocking about sound could possibly lead to internal dmg(if there isn't some already). Car only went a block and then up into the yard so I'm hoping it won't be REALLY bad... time to get it moved into the backyard and get the workbench cleaned off.

 

Brother owes you an Engine!

 

lol styx. I'm fairly confident he didn't do anything wrong and I'm positive that he'll be helping me pull and rebuild the engine. The engine lasted 220k, wish it had lasted longer. Gotta figure out what caused the failure now. I'm hoping to find a something cheap I can throw in there while I rebuild this beast. If not I'll just be making the 300zx my daily driver for a bit. =D