1991 coolant sensor

[Gale77]

How do you replace a water pump on a 1995 Buick regal custom, and is there an image of the procedure?

[carriedi]

which engine, 3.8 or 3.1

3.1
https://www.youtube.com/watch?v=Hb6UoX6XFgk

3.8
https://www.youtube.com/watch?v=29M80aN9Z_4

[carriedi]

If it is not external and it's a very slow leak, what is the rest of the story?

Are you talking about a 2006 Lucerne? What makes you think that it is leaking? what are you doing to keep it running when you have this leak? The more information that you can tell me, the more I have to give an opinion on.

Basically if you don't have an external leak but you do have a leak, it would mean you have an internal leak.

However, a very slow external leak may be a leak that you just don't see.

[peterz]

It is lucent as I stated with 123000 miles on it. Why you ask the Reserve tank goes below the fill line 3 times after I fill it. I also smell antifreeze now and then ununder he hood.

[carriedi]

I am unfamiliar with a Buick Lucent. Is this in the United States?

Smelling anti freeze means there is an external leak somewhere. You may need to do a cooling system pressure test and look for the leak. Water pump, intake gasket, hoses, radiator... A pressure test may not be conclusive though. Sometimes water pumps only leak when they are in one particular place or after it cools down. So for that leak you may have to look for staining where you can see where collant has leaked over time but may be dry when you check it now.

[peterz]

I am still waiting for help on the 2006 lucent with 123000 miles with a internal coolant leak on 3800 series engine. Was told that it maybe the intake manifold plastic ring on the plenum. Is this true?

[carriedi]

if you sometimes smell antifreeze under the hood why would you think you have an internal coolant leak? Do you have excessive white smoke out of your tailpipe? Do you smell coolant out of your exhaust? Does your vehicle have a misfire when you first start up after sitting overnight? Does your oil look discolored (coolant mixed with oil)?

Yes, you could have an intake leak coolant either inside the motor or externally. Being able to sometimes smell it would lean towards leaking externally. A cooling system pressure test would be the first step in finding the leak unless you can visually see/find it when you can smell it.

Or you can replace your intake manifold gasket and see if that takes care of the problem. I think finding the leak would be better though. could be intake, could be water pump, could be a hose clamp not tight enough...

can you give me a VIN number so I can identify your exact vehicle please? thank you,

[Frustrated]

I can't find the coolant sensor on my 1991 Buick Regal Custom 3800 6cyl 3.8l

[carriedi]

here's a picture. The coolant temp sensor is in the same place but one vin number will have the Electronic EGR valve by the sensor