L16 water temp

[71Ratsunguy]

my new summit mechanical temp guage says I'm running at 150 on the freeway at 70mph, 86 degrees today. My dash guage shows just behind the line. I have no idea what thermostat is in it, it's been over 5 years since I put one in. I overheated it and had to do the head gasket, I had a leaky radiator at the time. My question is, what thermostat did they come with or what temp does the line on the stock guage represent as far as operation temp? It's possible I put a low temp stat in it when I was worried about it getting hot. I am not sure, just seems low to me. I had to install the sending unit into a 'y' fitting (all I had at the time) into the line that comes out of the back of the head and into the heater. I have 13psi cap, so I know it's pressurized enough that the sending unit is getting a proper reading, right? Because of the y fitting it's kind of angled back from the flow. It's going to be my daily driver now for who knows how long, until I either fix the head gasket on my truck or buy something else, which really isn't in the books right now. I live in Redding, ca and last summer we had a lot of days between 100 and 112 degrees. Just want to make sure I have my cooling system and guages all set before it gets hot.

[datzenmike]

Your thermostat is missing or stuck open if at 150F, or that summit gauge is crap. Don't trust anything...

 

 

Get an IR (infra red) gun and 'shoot' the thermostat housing.

 

 

It's the only way to be sure....

 

 

About 185-190F would be just right. Take note where the stock gauge is reading as it warms up and you can take that gauge back.

 

 

.

[flatcat19]

Depending on where the sending unit for AFM gauge is...150 could be correct. 

 

Normal temp range with factory sensor and thermostat should be very close to 180*; give or take 10*

[datzenmike]

 I had to install the sending unit into a 'y' fitting (all I had at the time) into the line that comes out of the back of the head and into the heater. I have 13psi cap, so I know it's pressurized enough that the sending unit is getting a proper reading, right? Because of the y fitting it's kind of angled back from the flow. It's going to be my daily driver now for who knows how long, until I either fix the head gasket on my truck or buy something else, which really isn't in the books right now. I live in Redding, ca and last summer we had a lot of days between 100 and 112 degrees. Just want to make sure I have my cooling system and guages all set before it gets hot.

 

That's no good!

 

It will only read anything when the heater is on and there is flow. Needs to be in the thermostat housing.

 

Your cooling system does not need to be pressurized to have or give a normal temp reading.

[racerx]

Can't u boil the stat and see where its opening since u are not sure what temp. Ur stat should open. Then take out mech. Sending unit, get a small pot w boiling water and a big face temp. Gauge and stick the unit to the hot watrr, see what temp the stat opens. Correlate this reading with stat and gauge. But bring pot to car and let it sit by the upper hose. Have a friend look at the temp in your car then u will know what is temp at what line. I did this not too long ago and come to find out my stat was slow to open at 180. It was opening up at 205 or so. Just be careful with very water.

[71Ratsunguy]

I thought that's a direct out to the heater, there's nothing regulating it, straight out of the head

[71Ratsunguy]

it's the out of the head before the heater

[71Ratsunguy]

My factory dash guage is reading below the line. what thermostat is stock? 180? Is that what the line means for operating temp on the dash guage?

[datsunaholic]

it's the out of the head before the heater

Yes, but nothing is flowing past it unless the heater is on "Hot".   Otherwise the heater valve is shut, and so it is just getting conducted heat.  It's not an accurate location for water temperature in any case.

[racerx]

180ish  is good operating temp..but you are not sure how the temp line corresponds to the actual temp., right?  That's why I advised you to have stat, mechanical temp sending unit and have a big face thermometer in a pot with semi boiling water but hot so that the stat. open.  I think water boils at 220 degrees..then you can correlate all three: you will see when the stat opens because you will see what is the temp. on the big face thermometer and then most important you will see where needle is at the temp. gauge of your car. I will assume half way.  Good to have a friend inside the car and see where the needle is at on the gauge while you or your friend is placing the big face thermometer, sending unit and thermostat in the pot. Good luck let us know what happened.

[DanielC]

Water boils at 212 degrees Fahrenheit, at sea level.

[datzenmike]

Hard to see when it opens or starts to open in a pot or water. If I suspect a bad thermostat I just get another, they are not worth the bother of removal and a gasket. An IR gun will tell you the temperature in real world engine conditions, then just look at your gauge and see where the needle is reading. Follow it up so you know what the temp is at the beginning of the NORMAL range and what it is when stabilizes in it's run range. I guess you could block the rad with cardboard and allow it to run hot to 190F just to see where the reading is.

[racerx]

Whatever you do don't buy your stat at Autozone. 

[datzenmike]

Always spend $10 or more, not the $3.79 at WallMart.

 

Always use antifreeze coolant mixed 50/50... and change at least every 5 years, three is better. This is probably the best insurance against a blown head gasket, failer water pump and clogged rad. 

 

Use ONLY distilled water.

[banzai510(hainz)]

BUY THE 50/50 . Walmark antifreeze. it mixed already

 

Dude, I think you fine. Dont worry about it.  Should maybe be hotter. But sit in traffic and see what is does.

 

Buy a  3 core rad. I got a OPL branded one from Amazon. 133$.  Seems ok.

 

 

with a Pressure cap will will boil over at a higher temp.

 

If anything youll blow the motor by putting so many clamps and hoses on this for a Lame temp gauge. Cause it will leak one day again

Stock gauge is fine.

[71Ratsunguy]

Thanks for the input guys. For some reason the aftermarket guage has only read temp twice, out of five days of driving, otherwise the needle has not moved wtf? It seems the stock guage is reading correctly. I could not put the aftermarket sending unit in the stat house because I didn't have the right adapters to make it work. I thought there is hot water running through the heater core all the time, just weather you turn the fan on on or not is the heater. And there's nothing interrupting that line straight out of the back of the head before the heater? That's why I tapped into that line.

[71Ratsunguy]

Datsunmike I'll have to check my thermostat, it's been 7 or 8 years since I did that cooling system work and the head gasket, then it sat for 5 years, then I moved, so I don't remember at all what I put in it, I should check. At least it's not getting hot, but again I just want to make sure I have everything squared away and that everything is working as it should, and that I'm getting correct readings before it gets to be 100 degrees or more. I overheated this thing twice before, but I have changed the radiator and stuff, so it should be good, I'm just a little skeptical at this point you know, don't need some bs happening as it's the only thing I have to drive right now.

[datzenmike]

For some reason the aftermarket guage has only read temp twice, out of five days of driving, otherwise the needle has not moved wtf? It seems the stock guage is reading correctly. I could not put the aftermarket sending unit in the stat house because I didn't have the right adapters to make it work. I thought there is hot water running through the heater core all the time, just weather you turn the fan on on or not is the heater. And there's nothing interrupting that line straight out of the back of the head before the heater? That's why I tapped into that line.

 

There is only water flow through the heater when the lever is moved from cold towards hot. This opens a valve on the heater to let hot water through. You would never want hot water flowing through the heater in the summer when it's hot. It would seriously heat the air.

 

Your sender needs to be on the thermostat housing and below the thermostat on the engine side. Your stock sender and gauge is fine. But if you just have to have the after market one you will need some kind of adapter if you want it to work properly.

 

If the thermostat is 7-8 years old it makes no sense to go to all the trouble of removing it just to put back in again, Replace it with a good $10 one. It's actually less work and you have a new one. Save the old as a spare.

 

I would borrow an IR gun and shoot the thermostat housing as the engine warms up while watching the stock gauge. Take note where 160F and 170F and 180F are reading on the dash gauge. Now when driving you know by looking at your gauge what the temp is.

 

I find my stock gauge runs about 1/3 of the way in the NORMAL range in cool weather. In the heat and highway driving, it runs at almost mid way up the range.

[racerx]

Maybe I miss something but is there a reason why you did not install or the PO did not install in the thermo stat housing? At this point, like what Mike said, just get a new one, just don't get it at Autozone.

[71Ratsunguy]

racerx my temp guage is mechanical, the threads on the fitting will not work

[71Ratsunguy]

So I've been getting hot air blowing on my right leg. Datzunmike I see what you mean about the lever, except that apparently my heat switch on the dash is not moving this lever to close the valve. Thing looks like hell too

Here's a better picture first one got turned sideways

[71Ratsunguy]

damnit, that looks like a bitch to fix, underneath there, my knees and back and neck hurt just looking at it

[banzai510(hainz)]

I had a white 100$ 510 and the heater didn't work

I got under there and open the valve and just keep it open and don't use the handle up top. since the valve is getting hard  I just use the vent .

 

there were 3 different valves on thru the years so if there is a valve better get the correct one.

 

as for the adapter yes it sucks on the aftermarket gauges  that why I say keep the stock one and if it works your fine.

[71Ratsunguy]

I haven't tried to move the valve manually yet, I'm thinking if I can, I'll close it for the summer time. But who knows the thing might break or burst a leak in the old hose, then I have to fix it right haha

[71Ratsunguy]

Ok sounds like the stock guage is fine, I still would like to make the aftermarket one work correctly, at some point, but im going to have to fix this valve too. Is it easy to find? Just make sure I get the one for my year or what? Since this is a project car, and will be for many years, I could just fab an on off valve in the hose, but I would like to fix it right. You know, one thing done, a hundred to go hehe. Don't want to Mickey Mouse anything anymore, if I fix it its going to be the right way