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Jabronie

Head gasket leak. Any video tuts?

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I have to replace my head gasket and I'm not a mechanic. So does anyone have a video they recommend on how to do it, and who you recommend to get one from?

77 280z 2.8 NA
 
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First thing to do is visit Nicoclub.com and download the factory service manual for the vehicle. You're not going to find a video that tells you all you need to know. 

If you want help, you should list the vehicle year, any changes to the motor, and you might want to provide info on the facilities you have to do to work in. 

On my 280ZX, it was much easier to leave the manifolds on the head when removing and re-installing it. Getting the cam and timing chain right is critically important.

Important: Look for threads about making and inserting a wedge that holds the timing chain tensioner in place. If you mess that up, you will have to pull the timing chain cover. Getting the timing cover sealed when you re-install it is a bitch if you have the head installed first.  

Label EVERYTHING. Every bolt and nut goes into a bag and is labeled, Every vacuum line must be labeled, along with the port it goes to.  And if it's fuel injected, the fuel feed and return lines should be labeled along with the connections on the fuel rail.  Sandwich bags and a Sharpie are your friends, and so is wide blue painter's tape.

Edited by Pilgrim

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Yeah my apologies. I edited my OP.
Ok I'll check em out, and thanks for the heads up on the timing chain.

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There was a recent discussion about this, including photos of the timing chain showing where the tensioner is. When I did the head on my 280ZX, I had no idea where it was and didn't get it secured correctly. It cost hours of extra work, and I never got the timing gear cover to seal when I tried to install it with the head in place.  I ended up paying a Z-car mechanic to do it again and get it right.

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There was a recent discussion about this, including photos of the timing chain showing where the tensioner is. When I did the head on my 280ZX, I had no idea where it was and didn't get it secured correctly. It cost hours of extra work, and I never got the timing gear cover to seal when I tried to install it with the head in place.  I ended up paying a Z-car mechanic to do it again and get it right.
How much was the bill ?


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I found this one online.

But I would still refer to a manual https://www.nicoclub.com/service-manual?fsm=280z/1977/77_datsun_280z.pdf

Watch the video, read the manual, its a fairly simple motor to work on. Ask lots of questions.

To me the cost is one thing to consider, but I dont like people working on my cars, i find that people cut corners where I dont, i really dont like going back and fixing peoples mistakes. If you can find a shop in SC that has done this type of repair before then that would be great.

IIRC the KA24DE motor off a 240sx has a similar fitment of the headgasket around the headgasket on the front cover, i was able to use Hondabond on it to seal it up, never leaked. https://www.amazon.com/Genuine-Honda-Hondabond-08717-1194-applications/dp/B00STVCWYY/ref=bmx_2/134-8296344-1317705?_encoding=UTF8&pd_rd_i=B00STVCWYY&pd_rd_r=d926952c-de54-4cf3-a89b-e8db9faaa134&pd_rd_w=EkDA4&pd_rd_wg=0GAxu&pf_rd_p=c5e1cf4b-c006-4b7a-bb44-797de0814d9a&pf_rd_r=FTC761W54E2DMSPJZQSA&psc=1&refRID=FTC761W54E2DMSPJZQSA

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16 hours ago, Jabronie said:

How much was the bill ?


Sent from my Pixel 2 XL using Tapatalk
 

It was done along with some other work, so unfortunately I couldn't pick it out as a discrete cost. However, taking the timing cover off and having decent access requires pulling the radiator, fan, water pump, and crank pulley.  I can't see less than 4 hours of labor there.

The challenge is that you have the front of the head gasket at the top of the timing gear cover and the pan gasket at the bottom. Replacing the timing gear cover requires you not only to keep the timing gear gasket in place, but to avoid messing up either the head gasket or pan gasket while putting the cover in place. I tried but could not get all gaskets to seal, and I've been working on cars for a long time.

I got lucky and found a gent at a local indy shop who actually worked on Z-cars at a dealership in his early career

Edited by Pilgrim

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On 11/29/2020 at 2:20 PM, Jabronie said:


 I'm not a mechanic. 

77 280z 2.8 NA 
 

How not is not?  You're probably going to break some bolts and/or studs, on the exhaust manifold, maybe even a head bolt if the head's never been off.  Injector hold-down screws break also.

How many miles on the engine?  How do you know you need a new head gasket?  What is leaking?  It's a job.

  • Like 1

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Good point about the potential for broken studs. The exhaust studs on the Z heads/manifolds are notorious for breaking over time.  IMO the most effective way to fix that is to take the head to a machine shop for the broken bolt or stud extractions.  I'm not good enough to trust myself trying to drill and tap broken studs when the entire head may be compromised if I screw it up. 

On my 280ZX head one stud was mechanically removable, but on the rear side of the head required a laser to cut out the old stud.

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Nobody wants to know what a "tut" is?  I do.

image.png

Edited by Zed Head

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1 hour ago, Zed Head said:

Nobody wants to know what a "tut" is?  I do.

image.png

It's from Christopher Robin.

Tut Tut.jpg

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Somehow I have this image of Tut with a NASCAR trucker's hat on, turning a wrench while in his gold robes.

That would make a good "video tut."

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Edited by Pilgrim

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One comment about pulling the head - on my 1983 ZX turbo the manifolds had bolts in places that I simply could NOT reach. Also, some bolts spanned a break between intake and exhaust manifolds, and held both of them in place. I spent hours trying to get the manifolds off the head while it was mounted, and simply could not.

I had to pull the head to get the manifolds off. I also re-installed the head with the manifolds already in place, and before doing so I replaced the exhaust studs with higher-grade material to prevent them breaking again.

Leaving the manifolds on makes the head much heavier, but it's worth it to avoid trying to mount them with the head already installed.  

Edited by Pilgrim

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If you decide to tackle it I will suggest raising the front with ramps or jack stands. It'll help your back. After about an hour I can't take anymore bending over. Also cover those thin fenders with towels or those plastic/rubber magnetic fender covers. You'll need a few special tools also. The timing chain wedge, head bolt allen socket, cam sprocket socket, torque wrench and few others I cant think of. Best of luck on whatever you decide to do.

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The bolts that hold the timing cover in place respond nicely to a small, handheld impact driver.  Be patient.  Do not give in to the temptation to just put a wrench on it to see whether you can make them pop loose.  Use of a power impact driver is at your own peril.

Getting the nuts on the front-most and rear-most exhaust manifold studs is, in my experience, a crapshoot.  If you snap off the stud, do not give in to the temptation of trying an 'EZ-out' remover.  Better to weld a nut onto the end of the stud.  Lots of videos available online to explain this procedure.

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I think I have a '77 intake manifold on my P79 in the ZX.  It doesn't have the webbing.  Perhaps I'm wrong, and it's an earlier manifold. But if he doesn't have the webbing it'll be slightly easier to get the exhaust manifold bolts out..I remember the EGR tubing giving me lots of problems when I first got the car before pulling the original motor.

Edit: I must have a '75 manifold, there is no EGR.  The webbing is what makes the exhaust manifold bolts so tough to get out/replace.

Edited by Reptoid Overlords

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3 hours ago, siteunseen said:

It'll help your back.

Check his avatar.  I don't think he's worried abut his back.

  • Haha 1

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