temp sender ? again
 

i posted and searched earlier about temp sender location,and found most still have their's in stock location in driver's side head.which will provide a higher more accurate reading?than in my edelbrock intake.can i use the temp sender i was sold for the edelbrock location or is the head one different?i asked this at parts store and got the glazed eye,mouth open look with some drool at the corner.

Re: temp sender ? again
 

Info that may or may not be useful...

When I did my engine swap, I installed a crate engine. The hole in he head for the sender was larger than what came off my '86. I switched it to a sender from a 70s model that fit the head perfectly.

It read high. Really high. Scared me pretty good during break-in. I used an adapter to put the old sender in the new engine, and everything was fine. Apparently the sender and guage need to be matched to each other. I have no idea if yours is. :)

Slonaker

Re: temp sender ? again
 

You can install the smaller unit in the head, by purchasing a brass adapter to screw the sensor into. The local auto parts stores have them available. It is called a "Bushing". I have used them for years and they work.

Re: temp sender ? again
 

that sounds like a plan.my only problem is i don't know if i have enough back space with a header tube there.are either of you guy's running headers?there is a plug in that hole right now,it doesn't have any way to connect.a pic would be great at this point.

Re: temp sender ? again
 

Sorry, no headers. What do you need a pic of? Just the sender in the head, the adapter, or what?

Slonaker

Re: temp sender ? again
 

here's what i'm talking about as far as no space between header and sender..i don't even know if this is complete sender without a pic.obviously there is some kind of connector i'm missing.the one i have in the edelbrock manifold location will not fit in this spot,i,ve tried two different gauges in dash from the manifold location and both hardly even registered any temp.my temp gauge is just a stock c to h.

Re: temp sender ? again
 

I have headers on all of my trucks and car and there is no space problem for the sending unit. The headers on my trucks come out and go downward slightly at that point and easily clear the sending unit. The header flanges get close to the sending unit, but I have been able to install them with no trouble. I am including pictures of the Son's 86 Chevy, My 84 and my 91, they all have V-8 motors and plenty of room for the temp sending units on the driver's side head.

Note: if you loosen your headers and slide them outward on a couple of long 3/8" bolts about 3/4 of an inch, that sending unit will come out and a new one will go in.

Re: temp sender ? again
 

thanks man..i'm starting to get the idea...that unit has two little tits sticking out that the hookup wire slide's over,i've got that... maybe mine's good,, i just need the correct connector crimped on in order to connect and find out.would you agree?...by the way piece's that's a sweet looking shop,if i had that much room,i'd never go in the house.

Re: temp sender ? again
 

The sender you have looks just like the one piecesparts has and the one in my '86. It would be the correct one for a later model truck like he and I have. The 70s sender made mine read high, so it makes sense (to me at least...) that a sender from an 80s truck will read low on your older style gauge.

The one I had at first was larger in diameter, and did not stick out as far from the head as the one you have now. It was the right one, according the auto parts store, for a 78 or 79 model I think it was. This is a pic of the sender that made my '86 gauge read high, and I think it is the one you need. It looks like it does not stick out as much, so it might give you the clearance you need assuming your head has the right sized (larger) hole, and you are able to run it without an adapter.

http://slonaker.net/images/truck/70s_temp_sender.jpg

Let me know if I'm not making sense. It wouldn't be the first time... :)

Slonaker

EDIT: I forgot to add that I hooked it up using a female spade connector on the end of the green wire that goes to the gauge. I just spread it open a little with a screwdriver, and slid it over the little protrusion at a right angle to the sender (parallel to the block). It isn't what it is supposed to use, I'm sure, but it fit well. I can put a connector on this sender if you need an example.

Re: temp sender ? again
 

not at all,very helpful info.it amazes me how some of the little thing's are the hardest to get right.iv'e spent more time and energy trying to get this figured out than alot of bigger mods on my build.and i can relate to your fretting on that temp gauge reading high on new engine,not something a feller want's to see on the maiden voyage.

Re: temp sender ? again
 

To all

I have been stumped by temperature sensors in the past as well. It would be a good community project to measure various individual temp sensors. A temperature sensor is nothing more then a glorified resistor that varies its value over temperature.
A temperature sensor calibration can be easily done in a kitchen provided that XYL is gone for the afternoon. Just hookup a half decent Ohm meter (aka DVM) across center terminal and body (that may require getting a loop adaptor and a large size nut) and suspended sensor into a pot of water. Get a good quality kitchen thermometer and place it into the same pot as close as possible to sensor. Bring water temperature as slow as possible – as this will allow sensor body to stabilize and record corresponding temperature vs. sensor resistance – say every 10 C or 20 F.
Adding dimensional outline characteristics should make complex swaps easier.

RF

Re: temp sender ? again
 

I JUST replaced mine literally days ago, it was right on the intake manifold and easy as pie to get to, I didn't complain! I bought the cheapie at O'Reilly's and it seems to work fine. Though I'd be curious as to accuracy too.

Re: temp sender ? again
 

yeah,that's where mine started out in the intake i thought it read incredibly low.so,i switched to head location and it only went up a little bit.guess i should be happy with that.

Re: temp sender ? again
 

Mine read 100-110 "warm" and I knew that couldn't be right, changed the sender and now it reads around 180-190 warm, which seems like it's probably about right!

Re: temp sender ? again
 

Did you replace it on the truck in your avatar or was it on another truck? If so, then the one you changed, that you said was on the intake manifold, was the one that feeds your computer. Do you have one on the driver's side head just behnd the #1 spark plug? That one is probably the one that feeds your temperature indicator on the dash. My 91 truck has two sending units (one on the intake manifold and one on the right hand head).

Re: temp sender ? again
 

The one in the avatar is, apparently, an '85.

http://faith.dixiesys.com/85-Silverado

Slonaker

Re: temp sender ? again
 

Yes I can guarantee there is no computer anywhere in that truck unless you count the CD/mp3 player that has a USB port :D

At least no computers hooked to the motor.

This is why I hate computers in vehicles:

http://faith.dixiesys.com/Galant/PICT0002

My mechanically sound 91 Vr4 is sidelined due to a busted computer, nothing MECHANICALLY wrong there, but the computer is a post toasty (the ISC went tits up, giving the ECU a nice near dead-short, why is there no fuse or other failsafe for the computer, WHY?). Keep the computers in your desk and away from my vehicles :whine:

Re: temp sender ? again
 

I agree whole-heartedly. I have enough problems with the desktop model. And there's a whole internet of diagnostic tools for it. Don't get me started on the limited capabilities of the ones in our vehicles. Especially when you can end up paying MORE for the (pre-Atari 2600 tech) one in your truck than you can a fully "Windows Vista capable" new desktop!!! :crazy:

Re: temp sender ? again
 

Yeah I bought that 91 Galant for the express purpose of learning about fuel injection, turbos, ECU's and tuning and all that 2fast2furious stuff so I guess I am getting my trial by fire now!

But I must admit, my dream and ultimate goal is to build a 500+ cubic inch big block with twin turboes and fuel injection with quadruple digit horsepower :metal: But I want to do it on the cheap and do it myself.

Re: temp sender ? again
 

i put one in that looks like the one slonaker posted except it had a spade connector,made by wells.in the head. it only reads just barely on the scale past C ,with my old c to h gauge.i don't have any reason to doubt it.i have a new 4 row radiator and a 180 thermostat,nothing seems hot. what is weird is i never have any pressure in radiator i can pull the cap off after driving it and no hiss or nothing.any ideas? also what would you guess my reading of just right of C at about 10'oclock converts too on a temp gauge with numbers any guess's?

Re: temp sender ? again
 

That's what I don't like about a C to H type gauge. It only tells you if something is different. If you don't know where the gauge is supposed to be, you don't know if it is right.

One thing you can do is to buy a cheap mechanical gauge and install it temporarily in the spot in the intake. It will tell you what your temperature really is, and give you a reference point for the future.

It sounds like you have plenty of radiator. My 3 row cools mine just fine here in Texas even when it is 100 degrees an the A/C is running.

If your system is not pressurizing, it sure sounds like you have a leak somewhere. Is your cap good? They are inexpensive, and a good place to start.

Slonaker

Re: temp sender ? again
 

there's no leaks anywhere and i'm not loosing coolant level,the cap is fairly new,but i thought the same as you,i'd start with a cap. it's the cheapest .if that doesn't do it.the only thing i know to do is take it to where i bought radiator and talk to them.

Re: temp sender ? again
 

Here is the what I did. I have a 74 that takes the large sender (80ohm) I put on newer heads that take the smaller sender (160ohm). The 80ohm sender is for the cold/hot type gauge and the 160 is for the one that tells your temp. So if you put newer heads on a older truck (73 to 8?) that has the cold/hot type gauge. Use 2 small senders 1 in each head and run a wire from each to the wire to the gauge.

Matt

Re: temp sender ? again
 

So is there a newer ( small sender) that takes one wire or are they all two wire? if so how do you wire it?

Re: temp sender ? again
 

Boatpuller, if I'm reading this correctly, you have the guage that shows C and H, and not the actual temp right?

If this is the case, I can help. When I bought my truck, running good, it read right at a quarter of the way up. in other words, the first mark on the guage is where the needle sat. When I did the head gasket and new heads, I had to relocate the sender to the intake manifold, and plugged the head. No problems, guage read exactly the same. When I popped that motor and finally got my new crate 350, sender stayed in the manifold and the guage never changed. Still at the "quarter" mark. Once the engine is warm, the coolant is circulating through the passages with enough heat that the difference between the head location and manifold location probably won't matter.

As for your cooling issue, it's most definately gotta be a pressure leak. Do you have a cooling system pressure tester? If not, go rent one. It's basically a bike tire pump that plugs into where your radiator cap would go. You pump it up, and look for the leak. If it doesn't pump up, then you definately have a leak.

Hope this helps!