Well looks like a while since I updated this. Well the owner took the car home without me getting any significant seat time. He hadn’t insured the car so I only went around the block with it. I told him he would taking it at his own risk . And guess what- it over heated on the way to his house. Idled perfectly as he left and later I get a call with him saying -“ I think it over heated “. In fact it had. He’s not too mechanical minded, so it didn’t register that the steam at the gas station might be an indicator somethings wrong.
So I went to his house and sure enough - water in the oil. But why did it overheat when I idled it at my house forever and took it around the block with no problems. Took the radiator to the radiator shop and they said it was toast. So we proceeded with a HG replacement . And of course while we’re at it we had the head sent to the machine shop for a valve job. Running water in this engine had just caused too much damage and we we had to replace anything that the water touched.
Also found that the somewhere in its life the valves made contact with the pistons . Since the cam sprocket was on #3 , I figured someone didn’t get the adjustment right the first time or something like that. We pulled the freeze plugs and were glad we did, they needed changed because of the water . The head just needed a slight skim to get it true and the valve guides and valves were in good shape. The machinist just had to touch the valve seats a bit.
So I get the engine all back together and it runs perfect! I check the oil and I’m still getting water in the oil- WTF! Now I’m worried that the block is cracked . The owner is freaking out and thinking he is in too deep. In my mind, it runs too good to be a crack block. No bubbles or air in the radiator . How to figure this out? So I got a radiator pressure checker from Oriellys .
I pressurized the system at normal pressure and with the valve cover I could here a faint his coming from the timing cover -down inside . But what am I hearing ? So I bumped the pressure up to 15lbs and bingo - the seal on the timing cover that was hissing is now spraying water into the timing cover . Good news is I found it, bad news is I have to pull the hole front end apart again.
Alas , owning a vintage machine can go like this. I told the owner that in the end he will have one of the nicest 280z’s in the Midwest when it’s done . And almost a rebuilt motor -ha. We are going to do the timing chain also