Headgasket leak 91 300zx tt

[whamo]

Im new to this forum but not to datsun/nissan. I have a 71 240z that we recently completly restored and a 04 350z. I am going to look at a 91 300zx today that is supposed to be in fairly good condition but has a blown headgasket. The seller isnt a mechanic and he says the cars starts and runs but shouldnt be driven (I agree and hopefully he hasnt) He tells me that water pours out of the headgasket itself. I will check the coolant and oil for signs of contamination when I get there. Are there any common areas for a headgasket to fail on these engines? Also what is the most common cause of a blown headgasket on this particular engine..... it seems to be fairly common from what I have heard and read.

[evildky]

Welcome to Nico

and externally ealkign HG is very unsuual, is it ossible the mechanic si a nt much of a mechanic and the leak is one fo the thousan coolant lines beneathe the plenum or behind the motor?

generally when the HG's fail it's water int he coolant or water int he combustion or combustion int he exhaust, but a coolant passage leaking outside the motor well I've never heard of that happening on a Z, is it possible someone did headgaskets and got a damaged gasket?

and feel free to post some pic's of that 71 in the classic Z section

[whamo]

Thanks, heres the link to my introductory 71 z car post.

zerothread?id=433702

I ended up buying the 300zx and no the water isnt leaking externally, its leaking into the cylinders and steam is coming out the exhaust. It sounds like the previous owner shut it down quickly and didnt try to continue to drive the car. What are the odds that headgaskets alone would fix the problem. I checked out the factory service manual and it doesnt look like pulling the heads will be that tough. My thoughts are to pull the heads, check for flatness and install some good headgaskets...... maybe the cometic style. I have used those before on high compression applications.

[whamo]

Here are some pics of my latest Z aquisition.

[evildky]

ok thats sounds more normal, and I'd still have the heads checked for flatness before slapping on a new HG

if the car is a turbo you're better off pulling the engine to get the heads off, not sure how difficult it is to get the heads off the n/a in the car but it should also be easier to ppull the engine, then you can go over the motor and replace the rear main while you're at it

[whamo]

Thanks, I decided to pull the engine and after searching the forum found that there are a few different schools of thought for engine removal. The Nissan shop manual shows the engine and transmission coming out the top together. Other references show them coming out the bottom, or various combination's such as trans out the bottom engine out the top. I hve allready dropped tghe trans out. What is the best method from removal of the engine? Do the turbos have to come off first? Is that even possible?

[evildky]

taking the turbo's off can be done wiht the eingeine in but yoiu have to unbolt the engine and jack the engine up, much easier to remove the negine

I like to take the trans otu the bottom, firts time it took me 8 hours to do get it all out, the secone time it took only 4 there is a steeo learnign curve, once oyu knwo what to do in what order it's a lot easier

[whamo]

Any tips on pulling the engine out the top? I have a 4 post lift and the only real problem I had removing the transmission was reaching the top driverside bell housing bolt. I had to use every extension I own to reach that bolt. I couldnt even get the tip of my finger on the head of that bolt. I just kept searching with the socket until I found it. I'm not sure how Im putting it back in...............

[evildky]

most of us leave that bolt out

[whamo]

Yeah, I'm considering that. But I think I have an idea how I can put it back in.

[evildky]

I put it back the first time, and left it our the secone time, gets old quick