What Part Is This?

[1991LS400]

Hey guys,

I was changing out my vacuum lines today in my 1991 LS 400 and replacing them with blue lines and everything came out successful except for one minor (or major) problem.

The picture below has a green circle around a turquoise looking part. It's plastic and has two prongs coming out of the sides with a vacuum line attached to each prong...as I was trying to pull the top vacuum line off the plastic prong snapped off inside of the vacuum line.

Here's a better view from the front...again, the part circled in green is where the top prong snapped off:

I have left the bottom prong vacuum line on it but the top prong vacuum line is disconnected right now and just sitting there. Nothing is happening to my car. Is this a major problem? What does this part do? That wouldn't happen to be some cover for my coolant temperature sensor would it?

Please help! And how can I get another one of that turquose plastic piece and how would I remove it to even replace it? It looks like a large nut is holding it down. I hope I have clarified myself enough. Sorry for any confusion. Any help would be greatly appreciated.

*NOTE: The pics aren't of my engine but it was all I could find to show you guys what piece I was talking about.

[91L3xus]

From the first picture, that blueish part looks to me like it's the PCV valve, something of which I'm still trying to locate on my car. I don't think it's too good for anything to fall down that hole, as it could adversely affect the internals. When replacing it, make sure the grommet around it comes out in 1 piece also.

[nc211]

The pcv valve is the black hose connection in the first picture, right about the "32" number lettering on the valve cover.

[91L3xus]

The pcv valve is the black hose connection in the first picture, right about the "32" number lettering on the valve cover.

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Oh oh, oops. Wrong engine.

[1991LS400]

still no help from anyone? waiting hopefully...

[nc211]

Man, you got me? I salute you for bravery to take on that chore. I'd send SK an email and ask him to chime in. I bet one of the guys at JP knows for sure.

[1991LS400]

Man, you got me? I salute you for bravery to take on that chore. I'd send SK an email and ask him to chime in. I bet one of the guys at JP knows for sure.

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To be honest with you everything was quite easy until I rushed into pulling that hose off and not realizing that turquoise piece was plastic and not metal like the other lines. There were many rubber lines that I had to actually cut off with a pocket knife since they had gotten "stuck" on there from so many years of heat I guess.

I'll send SK a PM or e-mail. I really gotta find out what this is and if it can adversely affect anything in my car. The line looks so minute and it doesn't seem to be doing anything to my car but I really don't want it just sitting there unhooked as it is.

[Lexls]

That's the Bimetal vacuum switching valve No.1

90925-05075 Valve, Bimetal Vacuum Switching, No.1

I only know because I have a parts book ;)

[1991LS400]

That's the Bimetal vacuum switching valve No.1

90925-05075 Valve, Bimetal Vacuum Switching, No.1

I only know because I have a parts book ;)

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Thank you SO MUCH for providing me with the name of the part as well as the part number itself. You're the greatest! However, can you or anyone now tell me what it does and how it may adversely affect my engine? The top prong line is disconnected but it doesn't seem to be doing anything to my car. Also, how do I get that bimetal vacuum switching valve off?

[SKperformance]

Depending on the temperature of the coolant it switches the vacume flow. It is a thermo switch.

If it doesn;t adversly affest your pocketbook for one then get it.

[pachocco1]

I have replace the very same item for the very same problem. It was broken for at least a year until I replaced it. I noticed no drivability change once it was repaired. I think I spent over a c-note for it. Bosch part or something. They must be very proud.