Help- Additional coolant sensor

[jaywish]

Hi,

I'd like to add an idiot light for the cooling system to supplement the guage.

I was looking over the engine and a couple of access points seemed suitable to me.

The most obvious would be one of the 2 the coolant exhaust tubes on the top front of the heads. Just curious why there are two sensors there already? Are they both for the guage (average temp)? Maybe one for the guage one for the computer control?

I was thinking of putting in a brass "T" here. Is the thread NPT?

Another spot which looked promising, it is a touch more hidden unless you are looking at the bottom of the car, is currently filled with a brass plug located on the left side of the block just slightly below and rear of the freeze out plug. This looks like a lot easier spot to work with. Also it is close to the access points for aux tranny and oil senders. This could minimize the wire bundling and routing for multiple senders.

Anbody know the thread size?

I ask about thread size as I'd like to be ready to go with whatever I'm screwing in so as to minimize coolant loss and the resultant air bubbles.

Also any thought about the different locations? Other locations?

I suspect the top end coolant ports might show a higher temp than the block port but I have no idea how much of a variation I would get.

Finally any suggestions for an idiot light sender that might fit the existing threads without an adaptor?

Availablity of different temperature set points? If the block is a tad cooler a sender set a touch lower would work fine.

Maybe a sender from a 5.0 block?

Thanks,
Jay

[Thomas C Potter]

Not sure about any thread sizes having not paid any attention to those yet, but one thought relates to the direction of coolant flow, be it from the heads down like some newer cars do, or from the bottom up as most older cars did. This could affect the best location of your sensor. Let me know if you want me to look in manual.

[jaywish]

Hi Thomas,

Thanks for commenting,

I learned something new.

I didn't know any motors cooled from the top down.

From the placement of the senders I've seen, I'm pretty sure this motor is from the bottom up since there are are least two sensors on the top which i believe is the outlet.

Jay

[merc406]

Why you need idiot light?

[RF Overlord]

Why you need idiot light?

^^^what he said^^^

According to my owner's manual, the car already HAS an idiot light...

[jaywish]

What I plan to do is add a combo idiot light for both oil pressure and engine coolant temp. I'd like the light as an attention grabber. I do check the guages periodically but if a light starts flashing I sure will look at the guage right away.

I had an opel GT with real VDO guages that incorporated an idiot light feature in them. It is the best of both worlds.

If the Marauder already has an idiot light I dont know where it is. I did put the key on and look for a "Check Guages" light but I didn't see one.

Jay

[Marauderman]

Call Dennis Reinhart--he puts them on for alot of S/C cars for the cooler pumps...maybe he can help direct you as well

[jaywish]

I did call Dennis and talk to him about the basic concept as he had once posted his intention to work this out. I didn't want to trouble him by calling back with minutia of the job like thread sizes and such. I thought it might be fun to work out the details of a minor mod in a forum.