Part Numbers for 6.9L tachometer sensor

[olddesertrat]

Background: Have a 1985 F350 with 6.9L IHI engine and manual tranny, 189,000 miles. Tachometer has been acting flaky since bought truck. Reading on web general opinion is that tachometer sensor on IP gear housing is bad and needs replaced.

Original Ford part number: E5TZ17B384A

Looks like only tachometer sensor that has been available for all years. However some web sites say this is for 90-95 year trucks.

Just want to make sure this will fit my 1985 before spend $70 (sensor + shipping) on the tachometer sensor.

Thanks

 

[bike-maker]

Take a few minutes and put rtv on the top of the sensor, where the 2 wires come out. I made a Hershey kiss from the top of the sensor up about 1" up the wires.
If that doesn't work, pull the sensor out and check to see if there's any metal carnage stuck to the bottom of it.
I've fixed 2 of them that we're acting erratically by putting rtv on the top.

 

[olddesertrat]

Bike-maker: Please pardon my lack of lingo....what is rtv? Guessing it is something like silicone that dries and holds wires in place.

Did remove sensor and sprayed off bottom with electric contact cleaner. Little bit of extremely fine metal powder did come off...however did not make sensor work any better.

 

[icanfixall]

RTV is sealant that comes in the tubes from many different makers. I prefer the permatex ultra copper plus RTV. It heat and oil resistant. So far I have never had it leak in the last 25+ years using it on many different engines.

 

[jaluhn83]

I'm 95% sure that part number will work. I know I bought one recently through an online ford parts dealer and it worked. I do not know of any difference between older and newer idi sensors - if anything if would be the connector no anything that would be a major issue.

However, I would suggest cleaning the contacts on the sensor connector and seeing if maybe wiggling the wires helps any before buying a new sensor.

These engines seem to have issues with the sensor design - even a new sensor doesn't seem to help much. One thing I noticed is that the sensor is installed a bit further from the gear and thus puts out a weaker signal than would be ideal. I had issues with this when I first put my Isspro tach in and was able to improve it a fair bit my machining the sensor shoulder down a bit to get it closer. Not something that's too practical without the right tools though, and also risky if it gets too close and eats the sensor.

 

[OLDBULL8]

There is only one kind of Tach sensor for all IDI engines, normally they are dealer only, might find one on ebay, but who knows if they are good.

Do not use the Copper RTV on any electrical part including wires.

 

[ToughOldFord]

Background: Have a 1985 F350 with 6.9L IHI engine and manual tranny, 189,000 miles. Tachometer has been acting flaky since bought truck. Reading on web general opinion is that tachometer sensor on IP gear housing is bad and needs replaced.

Original Ford part number: E5TZ17B384A

Looks like only tachometer sensor that has been available for all years. However some web sites say this is for 90-95 year trucks.

Just want to make sure this will fit my 1985 before spend $70 (sensor + shipping) on the tachometer sensor.

Thanks

Considering it's an '85 part number it's pretty safe to assume it'll work on an '85.

 

[Agnem]

I sell the sensors, and keep at least one in stock.

 

[olddesertrat]

Thank you for replies. Did suggestions, used rtv, used electric contact cleaner on sensor end and connector pins....only slight improvement. So bought new sensor for on-line ford parts dealer for $65. Hoping it will work better.