260z Overheating issues
Posted 06 June 2012 - 09:32 PM
I'm new to the forum,
So I purchased a 1974 260z 2+2 off a fellow member and since I have had it I can't drive more than 15 minutes without it overheating.
so I have tested the thermostat, flushed it, checked fan,checked water pump cleaned it out all new gaskets screws and sealants, clean out rad,
pretty sure not the head gasket.
Noticed oil smelt like it had a small amount of petrol in it, checked hoses were not collapsing, seems to be ok while idling in driveway.
Ordering new aluminum radiator just in case, rich while idling.
would really appreciate some ideas and advice thank you.
Posted 06 June 2012 - 10:58 PM
Posted 07 June 2012 - 01:59 PM
Assume when you say 'overheating' it's the gauge reading high? Check the radiator/hose and make sure it's actually getting hot (water is flowing past the thermostat). It's such a cheap item and so easy to replace you might as well!
Posted 08 June 2012 - 12:12 AM
Posted 08 June 2012 - 12:55 AM
Posted 08 June 2012 - 07:58 AM
Posted 08 June 2012 - 08:18 AM
I would try a bottle of Chemiweld before starting to pull things apart, I managed to get 5 years out of Cressida with a bottle each year. It was pouring water out the exhaust, blowing water out the radiator, and oil in the water and water in the oil, running on a couple of cylinders sick as, 5 min's after treatment runs fine.
My Bob cat has now gone 5 years with one bottle.
Posted 08 June 2012 - 11:20 AM
Also check for a temp difference (with your hand before it gets too hot) between the top and bottom rad hose; if the one near the thermostat is cooler than the lower hose, water is not circulating ie could be either rad or tstat.
Posted 08 June 2012 - 11:30 AM
Posted 02 September 2012 - 03:44 PM
Let us know who the member you purchased it off is and we'll fix him up
Posted 04 September 2012 - 02:04 PM
Posted 04 September 2012 - 04:40 PM
If your radiator is clear, your thermostat is Ok and you water pump good then look for a blown head gasket, easiest way is to pull out the plugs and look for one that is has been steam cleaned.
Also make sure you have flushed your cooling system with a radiort flush to get the gunge and rust out of the water jackets around the block.
Posted 04 September 2012 - 05:28 PM
Is it a 3 core vl or vn or 'whatever bloody crappy car' it comes off radiator? And does it have a 12 inch thermo fan on it? If so it did cool fine with daily driving on the old engine, even in traffic in summer. I think the thermo fan controller might have been fried when I sold it, I assume they fixed this or might have replaced with an original fan setup?
Posted 04 September 2012 - 06:09 PM
Replace that thermostat first >> try chemiweld (even a few bottles) >> then pull your waterpump and check that
I think most likely waterpump but other 2 are easier to try first .. also just make sure to keep an eye out for milky looking coolant, sure sign of problems in the head as it leaks oil into the coolant
Posted 05 September 2012 - 02:54 PM
I think we missed that one! Dodgy cap will stop the system from pressurising properly so could cause the coolant to prematurely boil. Plus they are cheap and just about the easiest thing to replace on the whole car (provided it's not actually overheating and spitting boiling liquid at the time).
Correct me if I'm wrong there, that's just what my limited understanding suggests!
Posted 16 September 2012 - 07:19 PM
After that I would be looking at the thermostat and then the radiator. In this case start with the cheapest item and finish with the most expensive
Posted 16 September 2012 - 11:37 PM
if you take out the t/stat water has no restriction so it flows so fast through the radiator it cant cool down therefore boils,
I've read this statement before on this forum, pretty sure it is incorrect. Increasing fluid velocity increases the convective heat transfer, which will improve the efficiency of the whole system, which results in lower average water temperature.
Posted 19 September 2012 - 09:55 PM
Posted 20 September 2012 - 08:51 AM
My 306 pug showed this, and a bottle of cemweld fixed it.
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users