77'two_eighty

I bought a 1977 280z with unknown miles and the body is in great shape and I have been driving nonstop since i got it, and it started making some pretty nasty ticking noises and so my dad and I adjusted the valves to the tolerances in the manual so i am pretty sure it's not a valve tick. I believe it's an exhaust issue but not sure, pretty good exhaust smell in the car. On revving the engine it pops out the muffler coming back down. One of the lobes of my cam has some scarring on it, don't know what to make of that. I am planning on doing an entire exhaust kit to the car headers to tip, but i don't know what would be best. On motorsportauto they have a few choices but i'm new to the Z car, I would like something that sounds tough, but when i'm on the freeway i don't want to deafen myself. Any ideas? I have a few more issues that i have questions on so i'll list them and if people want to throw ideas at me that's cool and if not that's alright.

1. Tach moves up smoothly until about 4400 and then starts jumping around back towards 0 and when i shift it goes back up and does it again in each gear.

2. Radiator overflow was low so i filled it up to the max line, and recently it filled itself to overflowing. Car is running at about 195 and i don't know the regular operating temp. I'm thinking replace the thermostat (motorsportauto has a 160 and 180 so i'm confused there) and possibly the water pump if needed.

3. Heater doesn't seem to be working, even when the car is warmed up. Maybe due to issues with coolant.

4. Belt squeal is notable on takeoff, i replaced the alternator belt last weekend because it broke after driving 120 miles straight. The belts seem like they are tight enough.

5. Occasionally feels like i have a decrease in power. That's pretty vague but don't know how else to put it.

6. Car died the other day coming off the freeway, and then worked when i started it up and revved it a little. When you rev it, it comes back down to about 600 rpms and then goes back up to a little under 1k (875-950)

My first guess for the ticking and decrease in power is that some piston rings are worn out. Maybe a fuel pump or something.

I keep planning on doing a compression test but i've been pretty busy at work, so i guess some stuff may depend on the results of that.

I really appreciate any help i can get. Thanks for your time.

jfairladyz

2. That temp is about normal for a Z car in warm weather (not sure on temps up where u are though). My 280zx would regularly run between 190-200 unless it was fairly cold out.
3. Could be an issue with the heater door not opening. Could be a blocked heater core or a bypass valve stuck in the closed position.

As far as the ticking noise goes, are you sure its not the fuel injectors?

77'two_eighty

how do you go about testing that? i'd have to pull an injector and put it in like a mason jar and see if it's spraying correctly right? man i hope i don't need to replace those things. I had to replace every fuel system component of an 86 VW cabriolet i had and that was a real pain in the wallet.

jfairladyz

eh, my injectors were loud from the day i bought my Z and the 2+ years I had it I never had to replace the injectors on it except for one the first week i had it cause it wasnt tickin at all. They were just noisy.

BoulderZ

I'm with J, I'd be pretty certain it's the injectors. They're old school, and kinda loud, but work pretty well. You could do the pull-the-injector-put-it-in-a-jar test, but it's a huge pain to do that with the OEM "trombone" rail. Easier test: Get a big long screwdriver. Put the tip of it on the injector body while the car is running, and get your ear on/close to the handle. You'll be able to hear what the injector is doing, stethoscope-style (if you have an automotive stethoscope, use that). If what you're hearing from the screwdriver/stethoscope matches with what you're hearing in the ticking pattern, then you know it's just the injectors. Maybe they've just been loosened up by your driving it around lately. If the car sat awhile, maybe they're getting a little clogged or sticky with stuff that sat in the fuel system. Might want to try a new fuel filter and some injector cleaner for a couple of tanks, or a SeaFoam tune-up.

You mentioned topping off the rad o-flow bottle (good). But, have you checked to make sure the rad itself is full? Might have something to do with the no heat, or could be a core/valve prob like J said. While you're at it, you could flush the whole system and put new coolant in, which might not be a bad idea, considering who knows what previous owners may have done.

Finally, just a routine cleaning of your electrical connections might help a lot of the behavior. Seems like the EFI sensor plugs get corroded quite a bit by this age (mine were all green when I disassembled the car).

congrats on your new Z!
Dave

77'two_eighty

i'll try that my friend has an auto stethoscope so hopefully that is all i'm hearing but i still want to do an exhaust to the car, any suggestions? I was thinking the 3 into 2, but don't know much about them.

BoulderZ

I went with the 6:1 coated MSA header, and their 2.5" exhaust system. It installs really easily, but I haven't finished the rest of the car yet so I can't say anything about function or longevity. I would note that it does make it extremely difficult to keep your EGR valve functional, where as the 3-2 systems tend to work pretty well for that (making emissions testing much simpler, if that's a concern in your area).
Dave

theramz

1. Could be high speed coil breakdown, bad connection on the - side of the coil or the condenser.
2 don't add coolant to the overflow when it's cold. As the engine cools it sucks the coolant back in.
3 idk
4 Idler pulley may have bad bearing.
5-6 vacuum and intake tubing leaks.
7 check all the connections to temp sensors. If the ecu is reading cold engine then the cold start injector (top of manifold after the throtle body) will be firing to enrich the mixture causing the ticking.
BTW all VWs are expensive pos. jmo

77'two_eighty

lol yeah it was a pos, and i'm glad that i've been freed from that money pit and onto this new one At least if i put money into this one it will be worth it in the long run either resale or just having a sound fun car. Those sound like good ideas, thank you guys for your help. I will give those a try, also i used the auto stethoscope and found that my third injector from the firewall is loose, the bracket that holds it in place is wiggling, and it is making much more noise than the others, so i'm going to go get a bunch of replacement stainless screws for those parts. And while i'm doing that i'll replace the o-rings with the one's i already bought.