December 10, 20177 yr comment_537056 I'd add a quick compression test along with the rad. Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537056 Share on other sites More sharing options...
December 10, 20177 yr Author comment_537059 Hold them horses.....one disaster at a time. Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537059 Share on other sites More sharing options...
December 10, 20177 yr comment_537085 Â Get this kit and test for cylinder gases in the coolant system. That'll tell you if you have a HG problem. Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537085 Share on other sites More sharing options...
December 12, 20177 yr comment_537296 I believe you warm the engine with the radiator cap off (so you dont have to open a hot radiator) you should be able to see bubbles in the coolant if the HG is leaking. But, a leaking head gasket will certainly cause the overheating issue... Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537296 Share on other sites More sharing options...
December 13, 20177 yr Author comment_537389 Radiator got checked by a local shop...get a clean bill of health, tried the block test...sure enough turned yellow in aprox 20 seconds of hot running. I guess sitting for 20 years didnt do the hg any good. Off with her head then! Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537389 Share on other sites More sharing options...
December 14, 20177 yr comment_537451 18 hours ago, tzagi1 said: Radiator got checked by a local shop...get a clean bill of health, tried the block test...sure enough turned yellow in aprox 20 seconds of hot running. I guess sitting for 20 years didnt do the hg any good. Off with her head then! Since you have everything apart maybe it would be a good time to install that Stage 2 camshaft! Edited December 14, 20177 yr by esmit208 Mispelling Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537451 Share on other sites More sharing options...
December 14, 20177 yr comment_537453 3 minutes ago, esmit208 said: Since you have everything apart maybe it would be a good time to install that Stage 2 camshaft! And also I almost forgot a new exhaust header w/ emission plug bunge. I case you forgot. Have fun! Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537453 Share on other sites More sharing options...
December 14, 20177 yr Author comment_537462 The cam is a 276 duration by Camonics, The head is ported and polished....nothing is wrong with the header. Thee only part I'll need is a $20 head gasket...hopefully. Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537462 Share on other sites More sharing options...
December 18, 20177 yr Author comment_537813 Update: pulled off the head, found the gasket to without flaw, took the head (E31 BTW) to the machine shop to be resurfaced, got it back and was told they had to take 8 thau off...question is do I need shims?, the history of the head is kinda unknown, I remember getting it at pick and pull (it was ported and polished already) but I don't know if it was resurfaced in the past. Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537813 Share on other sites More sharing options...
December 19, 20177 yr comment_537842 If you don’t know how much them what shims would you use. You could measure the head thickness and figure from there- but I wouldn’t bother . I’m running .050 cut on my 31 with no shims , but cam gear advanced and chain guide adjusted . yo Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537842 Share on other sites More sharing options...
December 19, 20177 yr comment_537843 I don’t see any comments regarding the clutch fan assembly. I also think you remove the freeze plugs at this point and get all the rust out . Link to comment https://www.classiczcars.com/forums/topic/59121-71-240z-strange-overheatingcooling-system-problem/?&page=2#findComment-537843 Share on other sites More sharing options...
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