1980 280zx engine knocking

[Reece]

Hello! I am new here but I have recently started to restore a 1980 280zx and I have had some trouble. First, it took a lot to start but I finally was able to get it running smoothly but shutting it off after 5 minutes just to be safe. Whenever I had gotten in the car I noticed the clutch pedal is completely depressed, no resistance, nothing I pumped it a couple times after pouring brake fluid in the clutch master cylinder but still to no avail there was no pressure. Lastly, (I know this was stupid) I noticed on the engine block, I have no idea what hose or anything but there seems to be a huge opening in that hose, I’ll attach pictures and a video of the clutch pedal if I can. Thank you so much for reading this and please help! Thanks! 
 

 

ps: this car needs a lot of help, hopefully I can get it running better and smoother soon! 

[Zed Head]

The clutch pedal is two issues.  There is a spring that pulls the pedal back.  Sounds like someone removed yours or it broke.  And the clutch master cylinder seals might be shot.  Check the fluid first and try bleeding it.  The pedal should always be up even if the master cylinder is bad.

The open hose is the cooling fan system for the injectors.  It won't affect engine operation.  Most of them don't even work, unless it gets very very hot.

Your title says engine knocking but you didn't say anything about knocking.

Download the Service Manual and the 1980 EFI Book.

https://www.classiczcars.com/files/category/14-280zx/

Edited May 12, 2020 by Zed Head

[Reece]

Awesome! Thanks for replying!

Yes, sorry for not mentioning the engine knocking noise coming from the engine, I felt my post was getting too long and decided to monitor it more.

I first noticed the engine knocking when I started the car up, I do not know if the knocking was just because the car had no been started in over 20 years or because of another problem with the engine that is unknown as of now.

Whenever I got the car running smooth at idle I decided to rev it a little just because I was curious about it and as soon as I did that the knocking became more aggressive so I eased up on the throttle and it was barely noticeable. The actual knocking is coming from the header of the engine, and sounds like it is coming from the back of the header. 

Anyways I do not want to take up anymore time, thanks for the reply and hope to hear from you soon!

P.S. Sorry if this was a bad explanation, I tried my best!

 

 

[Zed Head]

57 minutes ago, Reece said:

Whenever I got the car running smooth at idle I decided to rev it a little just because I was curious about it and as soon as I did that the knocking became more aggressive so I eased up on the throttle and it was barely noticeable. The actual knocking is coming from the header of the engine, and sounds like it is coming from the back of the header. 

Could be an exhaust leak, they get confused for a mechanical knock often.  Could be low on oil, or a rod bearing.  Rods have been known to blow a hole in the side of the block if they let go.  Could also be something under the valve cover.

I'd check the oil first.

[siteunseen]

Agree with Zed Head on the rear exhaust leak. Not really a knocking noise as much as a ticking in my experience.

[Reptoid Overlords]

It might be useful to post some pictures of where the header, or exhaust manifold are.  You have the ability to put audio on the site, so maybe get it started and record the noise you are hearing.  I see a good bit of grime on the engine in your picture, no offense.  Mine looked like that too when I got it.  I remember my intake/exhaust manifold gasket had failed when I got my car as well..also the exhaust manifold bolts were so loose that they were almost removable by hand(they would've come out by hand if you could get your hand under the intake manifold). 

Edited May 12, 2020 by Reptoid Overlords

[Reece]

3 hours ago, siteunseen said:

Agree with Zed Head on the rear exhaust leak. Not really a knocking noise as much as a ticking in my experience.

 

4 hours ago, Zed Head said:

Could be an exhaust leak, they get confused for a mechanical knock often.  Could be low on oil, or a rod bearing.  Rods have been known to blow a hole in the side of the block if they let go.  Could also be something under the valve cover.

I'd check the oil first.

Now that y'all say that I remember after I had gotten it started it sputtered black sud, which could have been rust so maybe somewhere in the pipes there is a leak, thank y'all, that makes a lot more sense now haha!

[Reece]

24 minutes ago, Reptoid Overlords said:

It might be useful to post some pictures of where the header, or exhaust manifold are.  You have the ability to put audio on the site, so maybe get it started and record the noise you are hearing.  I see a good bit of grime on the engine in your picture, no offense.  Mine looked like that too when I got it.  I remember my intake/exhaust manifold gasket had failed when I got my car as well..also the exhaust manifold bolts were so loose that they were almost removable by hand(they would've come out by hand if you could get your hand under the intake manifold). 

I did not even think about recording it haha that is a good idea, tomorrow or the next day I am available I will go down there, start it, and get some better pictures/videos of the actual knocking (I hope it does not make that sound) but I will also upload some pictures of that sud I mentioned earlier coming from the exhaust!

No offense taken at all, my relatives have let it sit for too long... However, better now than never!

Thank you for replying!

[Reptoid Overlords]

Any progress with your car?