Chevy Silverado coolant leak

[Andrew]

Hi everyone, I have a question I hope I can get help with. I have a 2001 silverado with the 4.8l V8. 147K on it I think. I have a coolant leak from somewhere. When under my truck the oil pan has coolant on it. If I look on the top lip of the oil pan I see coolant there.Looks like it’s flowing from the front towards the rear. I usually park with the nose of the truck up hill. I was all prepared to swap the water pump and gaskets when I looked at the starter. coolant on top of the starter. That’s making me question if it’s the water pump. From what I can see, the water pump looks dry.

The intake on these are dry, no coolant flows through them, and I had my intake gasket changed about 4 years ago. I thought about head gasket(s) but since the coolant is on both sides of the oil pan that seems unlikely to develop the same leak in each side of the engine. Truck runs ok. No water on the dipstick. When running, the truck has some white vapor in the exhaust. it’s light, but there year round.

I have researched and come across information that the water pump is the likely culprit, and that the fan is blowing the leaking coolant around the engine and it’ll end up exactly where I’ve described. Does this seem reasonable?

Edit: no evidence of hoses leaking, no visible leaks when running, etc. coolant is only on the lower parts of the engine sides and rear.

Topic

[Jeff Ketchem]

Sounds like you may be on the right track. I would look into a cheap bottle of UV dye and a cheap UV light from a parts store, set a piece of cardboard under the truck and let it run and reach temperature then use the light to look for the magical glow. The cardboard will also help direct you if it makes it past the fan.

[Christian]

Never thought of using UV Dye I will have to look into that 🙂

Well I would say that there was a new Eric video on youtube you might benefit from. If your afraid of the fan blowing the dye all over the inside of the engine I would use the dye and perform the [u]Coolant pressure test[/u].

Happy hunting owe also this will let you know if you pulled a me and over flow the coolant through the reservoir overflow and then wonder why there was coolant everywhere. This was long time ago, I looked for a leak for days and only came to my own dumb conclusion.

[valde]

First just do coolant pressure test without dye. If you then find general area of leaking you may want to take something like fan shroud of an do it again.

[Andrew]

I’ve thought about a coolant pressure test actually. Should the car be warmed up with thermostat open for this, or would it be ok to do it cold?

[EricTheCarGuy]

Here’s the video on pressure testing. No, you don’t want to have the engine warm when you perform the test.

Also, here’s a link to an article you might find useful.

http://www.ericthecarguy.com/faq/what-to-do-when-your-engine-overheats

Keep us posted on your findings.

[Bill]

The most common coolant leak problem on GM trucks is the gaskets between the water pump and the block . They are very hard to see without a pressure tester and getting under the truck with a good light. When they leak the coolant migrates along the pan rails and drips off of the bottom of the oil pan. I don’t know if you can buy the gaskets or not but with the mileage on it the water pump is on borrowed time anyway. If you change it be sure you use the correct torque on the bolts.

[rod]

I also have a 2001 chevy silverado 4.8, same problem. Mine was a head gasket passenger side. I replaced both. Your description of the leaks matched mine exactly.

[Author]

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