I have been dealing with water in my 4th cylinder for a while. I found out water was leaking into the cylinder when my friend's dad did a compression test on it, and noticed that it sprayed a little water out. At that time, the water was only trickling into the 4th cylinder, and had not mixed with any oil. This was over a year ago. About a month after that, we tore the top half of the motor down, put new tensioners and timing chain, new front cover gaskets, new oil pan gasket, new head gasket, and torqued everything down. The car ran, but I noticed that water and oil were mixing five minutes after the car was running. I had forgot to thoroughly scrape the head and block, which caused the massive water leak. I tore the head back off, scraped the head and block, put the head back on, new head gasket, new oil, and my Z ran again. Two days later though, the motor seized due to water leaking into the 4th cylinder again, and I had spun a rod bearing on my 1st piston. At that time, I had assumed that the spun bearing was due to water and oil residue being inside of the motor when it mixed water and oil the first time, and when the oil change was done, the residue remained. The car was down for around seven months due to funds. I was originally going to have the crank micropolished, buy a new rod, and put new rod and main bearings in. I lucked out though, a guy had listed on ebay a complete block (P30 I believe), two four speed transmissions, an e88 intake manifold complete with carburetors. The deal was that everything was free, provided the bidder come and pick everything up. All I needed was the block, but I figured it was a good deal to get everything. I jumped on the deal, and was the lucky person to get the setup. The only problem with the block was that the seller had broken two head bolts off when removing the head, which was easily fixed. The motor was in good sound condition, out of a '71. The only reason it was taken out was because the head had bad valve guides, and would smoke on startup. The seller took the reason to do work on the motor, pulled it out, and was doing an awesome v8 build. I took the motor to a machine shop, they checked it out, said the cylinders had minimal wear, that it was a good block, and got the broken head bolts out with a carbide bit. I bought the necessary gaskets, bolted my old head onto my new block, and dropped the full motor back into my Z. The motor ran without any real problems for around two weeks, until it began to leak water and oil again, via the 4th cylinder, same as all of the other times. The vehicle hadn't been driven at all within the two week period, due to the fact that I had to get insurance first. As soon as I did start driving it, it began to leak water into the 4th cylinder. At that time, I had deduced the fact that my head was more than likely warped (the motor used to overheat), and that was causing the water leakage. I took the head off, put a straightedge on the mating surface, and noticed that it had some warpage to it. I went to pick-n-pull a few days later, to find another e88 head for my block, and I couldn't find any there. I drove to all 3 pick-n-pull's within a 50 mile radius, and couldn't find anything there. I logged onto Zdriver, and made a post, requesting an e88 head to buy. Tom (theramz), had told me he had a spare e88 head laying around from his 260z parts car, and that the head was free, as long as I picked it up. I took Tom up on his offer, and a few weeks later, my friends and I were on a trip to Nevada to pick the head up. We drove down there, talked to Tom for a little while (btw Tom, I noticed you're selling your mounting brackets for your disc brake conversion on ebay, good deal!), he took me out for a ride in his Z, which was some fun [img]images/smilies/biggrin.gif[/img]. We drove back, and a few days later, I had taken the 240Z head (my original), and the 260Z head (the one Tom gave me) down to a local reputable machine shop, and had them checked for warpage. The 240Z head was less warped, so I paid to have it boiled, pressure tested, and resurfaced flat. I was pleased with the work they did, and I bolted the head onto the motor a week later. The car ran again, but only for a few days before it began to leak water into the 4th cylinder again (reaccuring problem!). I had assumed that I must have been doing something wrong with my head gasket or torque, so I did some research, compiled data, bought a new head gasket, bolted it back on, and the Z ran again. No less than a day later, water was in my 4th cylinder. There was no water in the oil at all, but I noticed there was water in the cylinder when I went to make sure the plugs were gapped right. I noticed the spark plug was wet, so I got my dad to come outside, and watch to see if water shot out of the spark plug hole when I cranked the starter. Water shot a good four feet out of the motor, out of the fourth cylinder. I tore the head off, and there was around half a cup of water in the cylinder. At that time I was livid, because I figured the only problem could be my head was cracked. I took the head off, and took it down to the machine shop, armed with pictures of the water in the cylinder and video of the water shooting out of the motor. I had them check for warpage again, and had them pressure test the head again. They pressure tested the head right in front of me, and even went as far as to remove the valves from the fourth cylinder to make sure it wasn't cracked somewhere around the valve train. The head passed all pressure checks, which elimates the problem of a cracked head. I very seriously doubt two blocks would both be cracked in the exact same place, so I eliminated that idea.

The only idea I have left is that the intake manifold may be cracked due to the fact that there is a water line that runs through my intake manifold to cool it down, and to warm the carburetors up faster on cold days. If the intake isn't cracked, then the only other thing I think it could be is a bad gasket between the carburetor spacers and carburetor on the back carburetor. I bought a rebuild kit, and rebuilt the carburetors, and now I'm just waiting to bolt the head back on, bolt the carburetors onto the other intake manifold that the guy from ebay gave me, and see if it leaks again.

Is there anything else that could possibly be an issue? I figure that the head is pretty much perfect due to the fact that it isn't warped, and it has no cracks. The block shouldn't be cracked, and if it was, it'd be like a one in a million chance that it was. The only other idea is that there is a leak somewhere in the intake manifold/carburetors, and that is the only other lead I have.

If I have missed anything, please let me know! Sorry the post was so long, but I figured that I might as well write everything in detail so that I might fix the problem.

 

I'm changing your name to Saint Job! The manifold must be the culpret. You should plug one end and try to pressure test it with a water hose or take it to the shop and check with a vacuum gauge.

 

lol, that could be my name under my name, if that makes any sense (registered user). I hooked a water hose up to it, and it didn't do anything but spray muddy/rusty water out at my girlfriend. I hooked an air compressor up to it, and it shot even more rust/mud crap out, and I didn't notice any leaking. I don't know if the leak actually lies within the intake or with the gaskets, but due to my deduction, I believe the problem to lie within the intake manifold.

I'm kind of lost as where to go, but I hope to figure something out. We'll find out this weekend, hopefully.

 

I have enough to build another motor as well, provided I get the crank micropolished if I want to use the 240Z crank. Can someone say 3.1 stroker? lol.