Pickup up a 97 Z34 with 104,000 and it runs great! As I drive along below 2000 rpms it is fine, it sometimes climbs to 260 after a short time at 2200rpm+. If while it is very hot, I put it in neutral and I shut off the engine and start it again 10 second later it will drop into normal range with in seconds. It has plenty of clean oil and water, thermostat and temp sensor are new, I have tried to make sure it has been bled free of air, no debris on radiator, fans seem to work fine, no leaks have been detected visually.

What should I do now? Replace water pump?

 

Is there coolant in the system? If so, what color is it? If there is no leaks its prob. not the water pump and could be a false alarm (the coolant temp. sensor goes on these cars often).

 

First, welcome to the forum. You may want to post a thread introducing yourself.

Second, It almost sounds like an air pocket in the system. If you are constantly bleeding air, I would suspect a head gasket (but I could be pre-mature in that diagnosis).

Are you loosing any coolant?

 

Thanks everyone: after doing a combustion leak test I have found that it is a blown head gasket at a minimum and I will now decide if it is something I should try or if it is best left to the pros. I will know more after I get the heads off.

 

Mk, well..if u can get the heads off..then you can also bring them to the machine shop to be fixed and reinstall...doing the heads is not really very hard on these...