I suppose you could pull the water pump to see if it has those sheet metal impellers instead of cast. Some of those break off.

11 hours ago, gundee said:

I suppose you could pull the water pump to see if it has those sheet metal impellers instead of cast. Some of those break off.

Maybe i should try to do the radiotor test removing the thermostat to see if the water flows or not!

On 6/22/2025 at 1:26 PM, kully 560 said:

water does not really flow until the thermostat opens at temperature!

Do i still need to pull the water pump to inspect and flush the radiator to determine if its blocked somewhere?

On 5/1/2025 at 6:32 PM, Namerow said:

Faulty PCV valve? Not surprised. The quality control for these 'consumable' automotive parts is atrocious (spark plugs may be the only exception). They can cripple a car's performance, but spotting a defective item is difficult. You really need to install your 'tune-up' parts one at a time. If the car's performance collapses, you know you've just installed a new-but-defective part. Moral: Buy only the best -- even though they're just 'routine maintenance' parts. Even then, be alert and be suspicious. The auto business is a low-margin enterprise. Even name-brand 'replacement parts' manufacturers have to skate close to the edge in order to keep their shareholders happy. p.s. They do a much better job when it comes to supplying parts for new cars b/c now there are new-vehicle warranty costs involved and their customers (the auto manufacturer) will pay more to keep those costs under control. In the auto biz, it's all about $$$.

I will defer to others when it comes to your fuel pump circuitry. My thesis is all about making the system (your engine, along with its fuel and electrical systems) as simple as can be, so that problems much easier to diagnose. Once that's done, you can add back the complexity (emissions control equipment) as you see fit. If it were me, living in Panama and driving a carbureted 50-year-old classic, I'd limit that to the PCV system. All the rest of the 240Z's emissions control gear, viewed from a 2025 perspective, is -- not to put too fine point on it -- finicky crap.

My 72 240z has no emmission crap. All of these parts were removed by the first mechanic. We dont need that crap in Panama. Last mechanic doesnt show up. Just giving excuses to finish his work. Nevertheless, he did capped the PCV valve and tuned the carburetors in such a way. He argued that plugs 3 and 4th were getting fouled because oil was getting through the damaged pcv valve to the engine. This kind of logic makes no sense. I'm not a mechanic, but I'm not dumb. I'm planning on installing the new PCV valve this Saturday and checking how many turns he gave to each nozzle. To me the car lacks some punch.

Any advise on how to tackle this issue and forget about this mechanic would be positive. Im also doing a leak down test on all the 6 cyl and draining the radiator to see if there is any blockage.

2 hours ago, 72 Datsun 240z said:

I'm not a mechanic, but I'm not dumb.

Any advise on how to tackle this issue and forget about this mechanic would be positive. Im also doing a leak down test on all the 6 cyl and draining the radiator to see if there is any blockage.

I haven't checked in on your continuing problems for a while, so please catch me up on what you've done about suspected lack of water flow through the radiator. Does the car overheat?

Did you run it without a thermostat to see if flow happened?

Did you run it with the thermostat long enough for it to open and allow flow?

After reading about all the issues you've experienced for years, I have to wonder what keeps you connected to this Z.

Well no good mechanics in Panama. Car temperature reaches barely past half of the thermostat and 3/4 with thermostat. My problem is still under heavy traffic when engine starts to misfire. So i guess we will need to tackle this problem systematically.

Why would i sell the car. Its a matter of getting it fixed or not?

2 hours ago, 72 Datsun 240z said:

So i guess we will need to tackle this problem systematically.

It seems that's what you've been doing for the last decade and really aren't any closer to a solution than you were when you first recognized the problems.

Unless you have a strong emotional tie to your Z, I suggest moving on to another car that you can enjoy driving with confidence that it will run well and get you where you want to go and back home. Just a suggestion that could make your life less complicated and more enjoyable.

I once had a '74 Porsche that I never drove farther from home than I cared to walk back. I knew several AAA tow truck drivers by their first names. I was happy and relieved to finally sell it and eventually bought another that I've owned for 32 years.

Edited 3 hours ago3 hr by psdenno