Retired, broke and have gas guzzler Nissan truck

[Old Mechanic]

God be with your wife and I pray for her speedy recovery. The gauge should fairly rapidly get to normal operating temp which is close to halfway, and very steady regardless of operating condition.

Also check to make sure the fan clutch is not seized. You should be able to move the fan with some resistance with the engine not running. When you first start the engine the fan will make a considerable amount of noise for a few seconds then it will get much quieter. This means the clutch is working properly. If you see the temperature rise while operating the truck, say you are pulling a load uphill or something similar, you should hear the fan noise increase as the clutch engages more as the temperature rises.

The clutch is the aluminum hub that the fan is bolted to, and it is also bolted to the water pump. If the clutch has frozen then the fan is being directly driven by the engine and it will make a lot of noise. A normally working clutch fan will never drive the fan higher than 2500 RPM. This is so it will not use more power than necessary for proper cooling.

No (check engine light) codes would be a very strong indication that the thermostat is your main issue.

Prayers for your wifes health and better circumstances for yourself. I am pushing 61 myself.

regards
Mech

[JatMat]

I received the truck as a gift from daughter, it was no longer used in her business. The first tank, (someone had punched the trip meter) on the fill up when I calculated the mileage it showed 12.? a mile. On the fill up, I added one ounce of AutoMatic Transmission fluid per gallon. On the second fill up, I had not many more miles on the trip meter so I did not bother to calculate. During the second fill up, I again added the ATF to the tank (Adding the ATF lubicates the top end of the engine and it does work.) My Mercedes went from around 18 to 20-22 in town, hwy went from 24 to 29. Now, I just filled up the truck the third time and decided to recalculate. It ended up 17.94 miles per gal. This time I added some fuel injector cleaner.

Today, I changed the plugs again to a hotter plug, new air filter, new fuel filter and inflated to 40lbs from the 28 that someone had done. Tomorrow, the hotter thermostat (180) will be put in. I am now coasting every chance I get, anxious to see what the difference will be. I do appreciate all the responses that I got and they will be used. Thanks to all for the help.
Jim
I will be back.

BTW: The Mercedes computer notices NOTHING with the ATF in and runs great, I would suggest you at least try it. ONE ounce per gallon that the tank holds, first time, just fill up and put in the ounces that is the capacity of the tank, second time, the amount of the fill. I now only add the ATF on every other tank. Mileage has not dropped back.

[Frank Lee]

The top end doesn't need any lube from fuel. Couple that with knowing that oil in the combustion chamber does only bad things, and I think it's prudent to say simply don't add any stuff to the fuel, at all.

You may think one tank did better than another because of it, but tank-to-tank variations are often quite high due to external factors.

You don't even have a fuel log here for us to look at.

[oil pan 4]

Hotter plugs, hotter thermostat and oil up in the combustion chamber are not the way you want to go.
Zinc - Phosphorus anti wear additives and calcium based detergent in the ATF will clog the catalytic converter.
Zinc dithiophosphate - Wikipedia, the free encyclopedia

[JatMat]

Originally Posted by Frank Lee

The top end doesn't need any lube from fuel. Couple that with knowing that oil in the combustion chamber does only bad things, and I think it's prudent to say simply don't add any stuff to the fuel, at all.

You may think one tank did better than another because of it, but tank-to-tank variations are often quite high due to external factors.

You don't even have a fuel log here for us to look at.

And I don't plan to. My choice! As for the ATF, don't know why it works, but it does, if you haven't tried it, then you are just guessing. It was a method used by a good farmer of mine running around 20 trucks and tractors around a 5,000 acre farm, he did it and everyone who has tried it around my area swears by it. May do harm to plugs??? I don't know, don't care, if it is giving me 4 to 5 miles per gal better avg. The plug is recommended for my engine, but performs better, so I have been told. The hotter thermostat was recommended to me by a member of this forum for my driving habits. I fill up same station same pump, always has, it is owned by another friend of mine, so I have always shopped there. I am on a lot of forums, don't think I have ever been so criticized by folks who have not tried something. You are entitled to your opinion as I am. Thanks to the one who talked with me via PM and HELPED me as one who had the experience with my vehicle. Thanks for the help, the ones that did and good bye to everyone else. I am outta here.

[Frank Lee]

Anyone care to test oiling their fuel? I'm not gonna carbon up my top end to prove nothing.

[slowmover]

ATF is basically 5W-20 without the carbon combustion additives, and some added compounds not specified for motor oil. There is a nearly decade-old discussion of using ATF outside of design over on BITOG, without the numbers or studies or other to promote its use thusly (other products have a better and verifiable track record).

One is welcome, as always, to do with ones car as one will. And if the "experiment" seems successful, fine. Just that one shouldn't stop there if record-keeping indicates changes not otherwise substantiated.

Hope that JatMat will give himself a break and realize that the "contentiousness" of a viable site for information is not an impediment to its use. Vehicle enthusiast sites with overly specific consensus are of little help in the end. Records are just a tool, for example, but enable others to peer over ones shoulder in consultation on the problem.

Sounds like the repairs are underway, and a plan is in view for the immediate future.

.

[Frank Lee]

Sheet, I wasn't even being contentious. Smokey Yunick, engine development legend, told me in his book that oil in the chambers is bad. That I believe, especially after de-coking 2 strokers and oil burning 4 strokers.

It is a known fact among EMers that tank-to-tank fe calcs WILL show variations large enough to overcome the effects of "mods".

Many reputable sources say just about all additives are unnecessary. I didn't just make it up- I just put it out there "frankly".

[slowmover]

All additives would be unnecessary if fuel quality were consistent. And this is decidedly not so. What additive is another thread.

As to "contentious" don't be so prickly, as the whole of thread may be seen that way (to be generous to the OP's current reaction).