Front engine sensors

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GrandW
Posts: 224
Joined: Mon Aug 20, 2018 6:19 pm

Front engine sensors

Post by GrandW »

Hi All - been looking at the TSM, and maybe I'm just looking in the wrong place, but anybody know what the red and yellow sensors are? I'd like to replace them, but don't know what to buy... thanks.

It's an AMC 360, that's the front of the engine.Image

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1987 Jeep Grand Wagoneer
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Cecil14
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Re: Front engine sensors

Post by Cecil14 »

They're not sensors, they're CTOs (coolant temperature override valves). They open and close at various coolant temps, usually based on color, and provide or remove vacuum to different accessories. The TSM should specify what temp each color is.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank

Topic author
GrandW
Posts: 224
Joined: Mon Aug 20, 2018 6:19 pm

Re: Front engine sensors

Post by GrandW »

Cecil14 wrote:They're not sensors, they're CTOs (coolant temperature override valves). They open and close at various coolant temps, usually based on color, and provide or remove vacuum to different accessories. The TSM should specify what temp each color is.


aa
You're a genius. That led me to this page, which is super helpful. I need to keep pushing through the TSM because mine doesn't give any indication on temps etc.

http://www.drbob.tqhosting.com/tech/cto.html

The Napa part number for red is good. Yellow didn't work for me, but this one does: PART #: CRB 21024
1987 Jeep Grand Wagoneer
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Cecil14
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Re: Front engine sensors

Post by Cecil14 »

HA! No genius here, just ask my gf. :) I've actually never owned anything with CTOs, but I've seen them pop up often enough to recognize em.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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dodgerammit
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Re: Front engine sensors

Post by dodgerammit »

Yep. If you aren't needing smog certs, you can bypass them.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

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letank
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Re: Front engine sensors

Post by letank »

the other name is vacuum switch,

I have a list somewhere...

the yellow 3 port is niehoff FE410, or standard PVS 10

and for clarity, Michael's page

http://tc.wagoneer.org/search/label/Emissions
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
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tgreese
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Re: Front engine sensors

Post by tgreese »

Yep. Try "ported vacuum switch" with Google or Bing. Jeep calls them CTOs (Coolant Temperature Overrides), but that's an unusual name.
Tim Reese
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