M715 project underway 305 chevy with 200-4R auto

[jeeper]

I'm not really sure what a hot diesel would smell like. I don't smell anything unusual.

I'm wondering at this point if I may need a new water pump? When I open the cap I don't see any movement of fluid. I would think I should see the fluid movement?

I also have a new problem. Since I replaced the tensioner I am throwing my belt. The old tensioner had a lip on each side of the pulley. The new tensioner pulley is flat. When I rev the engine now the belt will slip off the tensioner pulley.

[Barrman]

You need a new tool! Yep, an infrared thermometer gun. Get the kind with a single dot. Use it to check temps all across your radiator, both sides of the thermostat, exhaust runners, hoses and about a million other things.

Where is your sender for the gauge? You have drivers head front outside, drivers head rear inside, passenger head rear outside, about 5 places on the cross over pipe and on the pump itself. Use your new gun to verify the temp really is what your gauge says.

You do have a reverse flow water pump in there with the serpentine belt, right? Along with a reverse flow fan? They are backwards from the fan and pump of a V belt engine.

Look for hot or cold spots in the radiator with the gun. It should be generally hotter on top and going to cooler on the bottom. If not, something isn't right.

To justify the new tool. It will help you look for dead cylinders, check bearings, brakes, tire temps, alternator bearings, how hot the cab floor is in the summer and you can play with the dog and cat using the dot.

[jeeper]

I had actually considered getting a thermal thermometer today but thought I'd better save my money in case I need some more parts. I'm getting low on fun money at the moment.

My temp sensor is in the cross over on the passenger side.

I'm pretty sure I have the serpentine water pump on the engine as well as the fan. I took the whole works from the serpentine equipped engine I wrecked last spring.

I guess a trip to Harbor Freight may be in order tomorrow.

With the cap removed should I be able to see the anti freeze moving in the radiator when the engine is at idle? I could when I had the 305 in there.

[Barrman]

With the thermostat closed, coolant should not be flowing freely. Only when the thermostat is open. Which way is it flowing? It should be upper hose to radiator and bottom hose to engine.

Do you have a dual thermostat cross over by chance?

[jeeper]

Thanks Tim.

I only have one thermostat and it is in the crossover.

I am assuming the thermostat is open when I'm looking at the fluid. I guess it may not be. Yet another reason to get the infrared thermometer.

[jeeper]

Okay so I bought a harbor freight infrared thermometer. I didn't really trust the thing at first. I was pointing it at my hand and getting a reading of 86 pretty consistently. Then I opened my mouth and pointed it down my throat. It came back at 96. That's close enough to the 98 I was getting on my fever thermometer.

So I went for a little drive after work today. (I had a short day of only 9 hours).

The crossover started at 29 degrees. (My thermometer in my garage says about 32).
When I got back from my mile or two jaunt my temp gauge had me at ~230. My infrared thermometer measured the aluminum crossover at 185. That is right where my sending unit is installed.

I'm guessing that means the fluid in the crossover is probably actually 190? (I put a new 190 degree thermostat in it this past weekend). The radiator was measuring about 125 degrees. It was warm but not hot when I touched it with my bare hand.

So I'm guessing I need a new temperature gauge and\or sending unit.

[jeeper]

So I had an extra identical temperature gauge on the shelf. I got two each when I bought my gauges last spring. I put the extra gauge in this evening and tried it out. I'm getting the same results with it.

I guess I'm looking for a new sending unit next.

[jeeper]

I must be losing my mind...

I just went through my old emails looking for the sending unit I bought for my gauge.

I bought it from Amazon so I was able to find it quite easily.

Anyway when I looked it up I could see the picture of the sending unit at Amazon looks just like the sending unit still in the block of my 305. I must have pulled the wrong sending unit out of my old engine.

I will be trying the other sending unit later this week.

[Barrman]

That would be great if it was that simple. Once you get the temp gauge right, start playing with it on the brakes. You will be amazed how much out of balance they could be and how just a few turns of a star wrench will make them all the same.

[jeeper]

Work slowed down abruptly this week. I ended up working only six hours today. I hope I get a full week in at this point. I've been working ten hour days for so long I wasn't expecting a slow down.

I will be watching what I spend for a while now.

That's a bummer too because I will be wanting a new temperature gauge and sender soon. I figured out today that I should be seeing 80 ohms resistance on my sending unit for my Teleflex gauge to read 200 degrees.

I have two sending units installed in my crossover right now. One reads 60 ohms at 200 degrees and one reads about 120 ohms at 200 degrees. So the 60 ohm unit reads hot and the 120 ohm unit reads cool on the gauge. I'm pretty sure one of the sending units used to make the gauge read correctly.

So I decided to start on some other tasks that I already had some parts for.

I wired the lights for the gauges into the three lever switch. I can now see my gauges at night without using a flashlight.

I am also converting my A/C compressor into an air compressor. I was planning on using a pancake compressor tank under the bed but can't seem to fit in where I had planned. I am now going to have to come up with plan B for a tank at this point. I will still wire a three position switch in the dash for it so I can run it tank-less for now. I have an oil separator for the output and will be figuring out a way to pipe that oil back into the intake side. (I hope).

I am also converting my alternator into a welder. I purchased an external voltage regulator last spring and am waiting on the non avalanche bridge rectifier I bought last weekend. I plan to take pictures as I go if anyone is interested.