300zx cooling issues

[ghstdrvr]

I recently bought an 88 Z na. When I drove it home it began to pour steam out of the overflow as I pulled into my driveway. Like most Z31s, the temp gauge doesn't even work but still even at idle gets really hot. It does smoke on start up but quits when it reaches operating temp. The hoses will bulge from excess pressure in the system. I've attempted to burp the system, after OT is reached it begins to push some coolant out then just bellows steam. I dont have any milky oil and the coolant level doesn't drop any from day to day. Today was the first time the level dropped, but waited til OT and now it shows no signs of coolant around the cap. I'm puzzled as to what the problem is because this is my first Z car. Any ideas of what to check? troubleshooting tips? or how to rule out certain issues? please help


Posted from Zilvia.net App for Android

[DeleriousZ]

Start with the basics. How does the core look on the radiator? Is your fan in good operating condition? Have you tried flushing the cooling system? Is your thermostat stuck?

[ghstdrvr]

The radiator core looks great w/o any bent fins or holes. The fan does stop when light pressure it applied at idle. I haven't got around to flushing the system but I know that the thermostat isn't stuck because you could see the purge of coolant before. I feel it's not a blown head gasket because the oil isn't milky and there's no steam in the exhaust, just rich startup smoke. Yesterday I was gonna burp the system but after about 10-15 min it started blowing steam. the steam didn't stop until I cut the car off after another 10-15 min of running time at OT. I then looked into the filler hose where no there was no sign of coolant. I've never had a vehicle show these issues in the cooling system and it literally has my head spinning. Any ideas where to go from here?


Posted from Zilvia.net App for Android

[DeleriousZ]

If I were in your position, I would replace the fan with a known good one, at least the clutch part of it, and flush the cooling system.

You should be able to find a working fan clutch online quite easily, check out z31performance.com for z31 specific classifieds.

Is all the ducting still attached to the radiator?