S130Z Posted January 19, 2010 Share Posted January 19, 2010 Hey everyone! I'll start this off with my setup. I'm running the stock turbo motor in my ZX that I recently rebuilt 1800 miles ago. I have minor head work done and I also have a GT3063. I'm also running MS-II is this makes a diffenece. I recently had a problem after an encounter with a Mach 1 on the highway. I was running some pretty high AFR's at about 15psi. After I pulled over from my victory, I noticed I had quite a bit of positive crankcase pressure. I made myself a catch can to help with the positive pressure so I could drive it without puning oil off the exhaust.(I had not realized I may have damaged the motor at this time) After realizing the car smoked under boost, I decided to run the usual checks on the PCV valve and ran a compression test. The back 3 cylinders were 100, 90, and 115(the front three were all at 155). The irregular numbers had me cross off the head gasket as a suspect. At this point I figured my rings or ring lands are bad, so my plan was to pull the motor and check for any possible cylinder damage before ordering pistons. This is wat is confusing the hell out of me. I pulled off my homemade catch can, which ended up having about 10 oz. of fluid in it. I proceeded to drain it expecting oil to come out, but no, it was coolant. It wasn't as green as coolant starts off as, but I could tell and smell it was coolant. So I then decided to pull the head off befor I pull the entire motor as I was running out of day light. To my surprise, the head gasket looked brand new, the pistons showed no sings of burning water, the cylinders were clean and the combustion chambers looked normal. I continued to check the head for cracks, but found none. In the morning I will look over everything again with more day light to spot a potential problem. Anyone have any thought of why there would be greenish water in my catchcan? I just dont know what to think about this. Thanks for any input you may have! Quote Link to comment Share on other sites More sharing options...
JSM Posted January 19, 2010 Share Posted January 19, 2010 You didn't state, but did you check the oil in the Crank case for water too? There was no evidence of water in any of the oil on the head itself when you pulled the valve cover? No milky oil? Also when was the last time you checked the catch can? Quote Link to comment Share on other sites More sharing options...
S130Z Posted January 19, 2010 Author Share Posted January 19, 2010 I have pulled the dip stiick before, and after letting the car run. There have been no signs of water in the oil. I am going to drain it tomorrow and make sure. I have had the catch can on the car for a week, and it was the first time I draind it. Quote Link to comment Share on other sites More sharing options...
roninjiro Posted January 19, 2010 Share Posted January 19, 2010 Where do you have your catch can lines hooked up at??? That is extremely odd you have no excess fluid in your oil pan if your blowby is coolant. Was all of the fluid coolant with no mixture of oil? Quote Link to comment Share on other sites More sharing options...
S130Z Posted January 19, 2010 Author Share Posted January 19, 2010 It was just streight coolant. It's almost like it is was vapor and then condenced back into coolant. There was just a tad bit of what looked to be oil and coolant sludge at the bottom, but not much. The catch can line is streight off the valve cover. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted January 19, 2010 Share Posted January 19, 2010 I could understand a little water/coolant in the catch can if you have a minor crak that lets a little water through into the oil which then evaporates when the oil is over the boiling point of water, to then condense and collect in the catch can. But not as much as 10 oz with no milky oil signs... Quote Link to comment Share on other sites More sharing options...
roninjiro Posted January 19, 2010 Share Posted January 19, 2010 Thats what i was thinking. But also I do not understand how you collected 10 oz in that short period of time. I am thinking you need to dye test the head for cracks. Quote Link to comment Share on other sites More sharing options...
S130Z Posted January 19, 2010 Author Share Posted January 19, 2010 Thats what i was thinking. But also I do not understand how you collected 10 oz in that short period of time. I am thinking you need to dye test the head for cracks. Well I went back and looked at the can. It ends up it's a 16oz can(I thought it was a little over 20oz). So now I would say there was maybe 6-8oz of water in it. But that is still WAY too much. I will also have to get it tested for cracks when I take my rod assemblies to the machine shop to get new pistons pressed on. Quote Link to comment Share on other sites More sharing options...
Mayolives Posted January 19, 2010 Share Posted January 19, 2010 A leak down test would have been helpful but it's too late for that now. You really need to look very, very closely at the head gasket for signs of where it could have been leaking. Quote Link to comment Share on other sites More sharing options...
S130Z Posted January 19, 2010 Author Share Posted January 19, 2010 I have been thinking about some of the compounds in exhaust. I know that H20 is a by product under certain cercumstances. Is it possible that the blow by from bad rings/lands could alow the water vapor to condesnse into the catch can? I also noticed the water wasn't exactly the original color of coolant, so could the oil mixing with the water give it a greenish hue? I know this is far fetched, but it's the only thing that came into my head as I sleeped. Quote Link to comment Share on other sites More sharing options...
roninjiro Posted January 21, 2010 Share Posted January 21, 2010 I have been thinking about some of the compounds in exhaust. I know that H20 is a by product under certain cercumstances. Is it possible that the blow by from bad rings/lands could alow the water vapor to condesnse into the catch can? I also noticed the water wasn't exactly the original color of coolant, so could the oil mixing with the water give it a greenish hue? I know this is far fetched, but it's the only thing that came into my head as I sleeped. Now that i think about it, that does make sense. I have had this problem before also, on my very first z. My scenario was more like cracked head and bad rings though. Also for me my car smoked white really bad as well as "coolant" blow by from the valve cover with no coolant in the oil. Talk about bad luck Quote Link to comment Share on other sites More sharing options...
Swervey McZCar Posted January 24, 2010 Share Posted January 24, 2010 (edited) It was just streight coolant. It's almost like it is was vapor and then condenced back into coolant. There was just a tad bit of what looked to be oil and coolant sludge at the bottom, but not much. The catch can line is streight off the valve cover. For what it's worth, I had the same problem. Did you check your coolant level before you tore it apart? Mine would use enough coolant to empty the overflow tank in about a week. I did comp check (normal) then tore it down. Found signs of coolant in 1 cylinder and the head gasket perfectly intact. I had been using a felpro gasket that blocks several coolant ports on the P90 head. I re-surfaced the head (JIC) and swapped to the Ishino gasket which is exactly like the OEM gasket. If you determine the head is not cracked, look for signs of coolant passing into a cylinder such as 1 really clean piston. RUIZ Racing had the same symptom but I never heard what his solution was. A Nissan mechanic friend informed me later the L6 was prone to coolant leaks (usually out the side) and the dealership would occassionally resort to using stop leak on them with great sucess (FWIW). Pic of blocked coolant passages. These are open on the OEM gasket and the Ishino Gasket Edited January 25, 2010 by Swervey McZCar Adding pic Quote Link to comment Share on other sites More sharing options...
S130Z Posted January 27, 2010 Author Share Posted January 27, 2010 Hey guys! got back from the ladie's house around 12, made myself a drink and started tearing* down the bottom end. Its about 2am now and have all the piston assemblies out. AND GUESS WHAT!!!!! The back three cylinders all have shattered ring lands! Good think new pistons came in the mail today. From what I could tell from the cylinders, they all look fine. I will get my new pistons pressed on tomorrow, hone the cylinders and start putting everything back together. Ill keep everyone updated on how it goes. Oh, I also need to rewire MS, so maybe this weekend she will be done! Quote Link to comment Share on other sites More sharing options...
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