81 Black L28E

Ok i just bought this car{IE NEW CAR POST}. I changed the oil and put a new filter on it .I purged the cooling system changed the lower rador.hose and therostat. It runs ok but it gets to the F on the temp gau. and sits there for a bit and then it gos up to almst the 270 mark and then it comes back down then it goes back up it got really hot last time AND DIDNT COME BACK DOWN so i turn it off it also kicks water back into the releaf tank it seems to have a broken or missing exaust bolt on the back of the manifold the very last bolt i can see here and feel the leak Ther is NO water in the oil
It also had a broken T at the back of the motor the bottom was broke out it looks like water ran thoughs rubber hoses and the T HOOKED THEM ALL TOGETHER I FIXED THAT TO........the injection fan seems to run for a bit after the car turns off and then it kicks off after a bit?????it seem to have a NEW water pump i can see the new seal and it looks dry
MY ??????? IS
Why is it geting so HOT and Why is it kicking water back into the releaf tank

81 Black L28E

I just ran her down the street to see what would happen it got warm like norm and the heater seem two work good intell i got to shell and then the heater got cold and the temp went up a little bit i turn around a came home. buy the time i got home the temp was right on the F where it would be on the other car the heater was still blowing cold air

Bleach

Is the radiator definately full of coolant still?

81 Black L28E

i just went out and checked the water level there was none both {ie over flow tank and rate}

the top of the motor was still warm and i messed with it an hour and a half ago it really cold out there

WildmaN

HI; It sounds like maybe your radiator needs re-cored. Also do you have the upper and lower fan-shrouds? Those are crucial in cooling. Also what about your thermostat? It sounds like the thermostat is stuck closed. WHich means the coolant will not get to the engine. I have had that problem with my '81 and '82. My other question is, does water shoot out of the overflow container like a geyser. It would happen especially if you revved it and watched it coming up. Hopfully not the case, because if so, you might have a head problem. My '81 did that, and I needed my head re-bulit. And that was a costly situation. Hope this helps. I am by no means a mechanic. But I have had my Z for almost 5 years, and have put over $2000 into him. I like to help people out if I can. ANd I learn as I go. And also I have done a lot to my Z on my own. Just self teaching

Bleach

Well, first of all you just said there was no water visable in the top of the radiator; right?
So that needs to be fixed. That could of been why your heater stopped working. No water flowing (or not much) through the heater core. Fill the radiator, put 1/3 in the overflow tank. Then drive it a little.

Once it is warmed up close to the F in the middle of the gauge, park it and leave the engine running. Look around and under the engine for any visable water leaks. That's a good first step.

If your radiator stays full, but overheats then maybe something is clogged.

81 Black L28E

ok i filled it up and took it for a little drive i got back and opened the hood water was shooting out of the over flow tank so i turned it off and opened the cap and put more water in it then i started it an it ran like norm for a bit and i watched it. all of a sudden it started to push water up into the the over flow tank and then it started to come out of the top of the cap so i opened it up and it came out faster it seems to push water out of the system when it gets up to pressure
or when it get to norm temp
water wasnt coming out of any thing eles but the over flow tank should i just try to cap it off also the water seems a little foamy

Bleach

...super high pressure in cooling system. Hmmm, maybe air pressure from your blown head gasket.

WildmaN

I hate to say it. But it does sound like your head and or gasket is bad. I had the same problem with my '81, and it cost me $1200 to take it out of the car rebuild it, and then I had to get another used head to have rebuilt. And finally put it all back together at the shop. Granted if you do it yourself. Bring the head to straighten or whatever they have to do so you can rebuild it. One it they were able to rebuild it, without having to do much work, or it straightens out in the oven within the first couple of times. Well I paid about $400 to rebuild on the used head. But then the labor was over $700. Hope this helps, and sorry to hear about your car. Been there done that.

81 Black L28E

thanks guys for all of your help iam starting to pull it a part today i will post pics and let you all know whats up iam going to order gaskets and a header today hopeful my head isnt to messed up but for $350 for this Z iam stoked ether way
what kind of whare iam i looking for to tell if my head is bad or if it is just the gasket when it get it pulled apart
hi ho hi ho its off to pull my head i go

Bleach

don't drop the chain, its such a pain
wedge a block instead, when you pull the head
hi ho, hi ho hi ho hi ho...

WildmaN

Yeah good luck to you, you still got a smokin' deal. The car is still pretty clean, and nice shape. Glad I could help, and everyone else, that gave you helpful advice. Keep us up on your rebuild!

Skully

ROFL! hahahaha

EatmyDust

I would have done a compresion test first befor pulling it apart. when you take your head to the shop all they are going to do is shave it cause it is probably warped, and then do the valve job. if you were smart you would take it to a machine shop with out the valves in it, and ask them if they could check it and tell you if it is warped. if it is in fact warped, have them shave it acordingly, then all you pay is far the labor in a shave. then do your valve job your self. If you have done it befor it shouldn't take you long. granted if you are a machanic, and have tools.

Zskyline79

Okay this might be a really big long shot. I had that overheating problem too, the car would like heat up under 20 min of driving. Put in a new thermostat still didnt solve the problem, so I had my mechanic go ahead and pull the radiator off to get it diped and cleaned. Turned out that my radiator had rusted through and that what was causing my car to overheat. I would say check the condition of your radiator.

81 Black L28E

well yesterday went well other than i hate heat shealds and manifolds but its more than half way broken down and i will post some pics tonight

81s280zx

i really dont think its your head gasket my car was doing the same exact same shooting water out of the overflow hole i just replaced my radiator and problem solved car runs great

EatmyDust

I'm sure the car was runing great befor the radiator was replaced. I would have just checked return lines to the radiator.

Bleach

That issue was a LONG time ago guys. The head was replaced since then along with the gasket and has been driving fine since then.