I have a coolant leak on my 2006 Chevy Uplander LS 3.5L. I found the source of the leak and I can’t seem to figure out if I have found the right replacement pipe. The thermostat housing bolts onto the water outlet at the block. Just to the right is a pipe connecting the water outlet to heater hose outlet. The pipe is secured by an o ring and it’s also bolted to the block. That pipe corroded and broke in 2 where it sits in the block. I found an AC Delco heater pipe- part 12570811 that shows it’s the replacement. It doesn’t look the same though. And it’s $68.99! I found that its parts are interchangeable with the Pontiac Montana SV6 and that pipe looks much more like mine. Plus it’s $36. I’ve attached photos of my pipe as well as photos of what I’ve found. Can anyone please tell me if u know which is the correct one? No one at auto stores around here seem to know much or care to help. I’ve got myself this far, so I’m def not paying someone to do anything else on my van. I know someone on here is much more knowledgeable. This forum has gotten me thru the last few months.

After removing throttle body from the top and the thermostat housing from the bottom, I was able to see the leak clearly when I noticed the play in the pipe.

Better view of the pipe and the space created between.

After removing the pipe. In this photo the thermostat housing has been bolted back onto the block.

The corroded tip I discovered after pulling it out.

This is the pipe.

From a different angle.

This one looks so similar. But they don’t included the diameters of the pipe.

This one shows it’s for my van. But as you’ll see there’s no availability. Plus look at the price.

They also include the dimensions.

 

Did you take the old one with you to the auto parts store to try and match it exactly?

 

I did. They are really no help at all.

 

I would bring it to the dealer to find out if they can figure it out. You can go in telling them you are looking for a price on the part. If you think it is too expensive you can pass on the purchase. There is no obligation to buy. I have done that before and the local parts guy was so helpful and understanding he gave me the part number so I could decide what to do. And certain parts at the dealer are not much more than the autoparts stores. Of course it could go the other way and you could get a parts guy that is not helpful and you waste your time.

 

Is it just me or does that pipe look like it’s been welded together? Maybe a previous owner found the part to be discontinued and resorted to welding it back together. That pipe didn’t come off of the assembly line looking like that. Van most likely ran hot at some point and rusted the line into.