Help with Installing Intake/Exhaust Gasket on 280ZX

[rubiconxj]

I've had my 280zx to the mechanic twice and it still leaks from the exhaust side of the gasket. He told me the header from MSA that was on it was toast. I ordered a new one and it didn't leak for about 2 days.

I can't afford to keep paying that jerk to "fix" the leak. Now he tells me that the head is warped. I talked to a reputable guy at a local machine shop who said that was very unlikely.

Anyway, how hard is it to change that gasket? I am aware that it is the intake and exhaust gasket. I have worked on American cars many times before, but foreign cars scare me. Is there a place I can find instructions on how to replace that gasket. Should I be concerned with breaking brittle injector harness or plastic when attempting this?

Thanks in Advance,

Jonathan

[evildky]

they are easy to work on but some of the bolts are a pain to get to, removing the intake and exhaust the forst time might take you a few hours after you've done it a few times more like half an hour, the injector connectors are brittle just take your time pulling them off

as for the leak a lot of time leaks around the thermostat housing lead to corrosion around the #1 exhaust port which results in the gasket blowing out, you can take your header in and have the surface of it checked to verify it's flat and true, and coat the intaek/exhaust gasket with copper gasket spray (I've had good luck with this stuff) assuming the corosion isn't too bad, and yes it's unlikely that the intake exhaust side of the head is tweaked but if yu pull the head you can have it resurfaced by a machine shop as I have done

it's also possible that your header mounting flange is too much thinner than your intake flange and the studs and washers that seat between them can't apply an even load due to the differetn thicknesses, a machine shop can surface the intake manifold to match the thickness of the header flange to make for even seating force

it's also possible if the leak is coming from the middle or rear of the manifold surface that the mechanic is a bonehead and simply didn't get everything cinched down correctly

the front and rear studs should be in the head before anything else, you then apply the gasket (I highly reccomend coating with a couple of coats of the copper spray first) then sit the header in place and apply the bolt tht goes to the top middle of the head, situate the header and gasket and torque that center bolt doen as well as the end studs and nuts, now thread the rest of the studs in along with the extra thick washers for clamping, just start the nuts as you want plenty of room to work the intake into place and put the bolts in the top at the ends of it first, torque them down and then start tightening the studs and nuts, once thats all done you can hook up the exhaust and intake piping

[rubiconxj]

Are bolts or studs used from the factory. From what I remember they are bolts. I assume they need to replaced with studs.

Also like I said the header is brand new. What gasket do you recommend, I've always had good luck with felpro blue. It is leaking from the port nearest the firewall.

Finally if I take it to another mechanic what would be a fair price for him to do the work?

Thanks for your help. I have a couple more projects to complete on this thing so hopefully you can help me on those once this one is over.

[evildky]

the top of the intake manifold has bolts and the exhaust manifold had one bolt in the middle (and maybe the 2 right below are bolts I can't remember for sure right now) the rest and studs and nuts, as for gaskets I've used a felpro, beck arnley and federal mogul and noticed no significant difference in any of them, as for what's a fair price that depends o how much work he has to do, if the manifold requires milling he has to strip the manifold and have it milled down, which will cost more then a simple gasket job, a simple gasket job shouldn't take more than a couple of hours tops at whatever their work rate is, I'd suggest trying to hook up with your local Z club (zcca.org) and find out who in your area they recomend as an experienced z mechanic, they might even hav a member willing to help you do it yurself and save some cash for speed aprts and if you havn't pitched the old header yet you might consider putting it on ebay, it likely can be re-used as the new header didn't solve your problem

[evildky]

ok I just checked, 3 bolts in the certer of the exhaust manifold, 4 bolts in the top of the intake and all the rest are studs and nuts