geezer

Has anyone replaced the internal water pump? How tricky is it? Accessing it looks pretty straight forward but it requires a special tool to hold the pump so the timing chain does not get out of sync. The cost for the parts is reasonable. If someone has done it please let me know.

donbrew

I have done it! I own a $50 one time use tool (but I may need it again for the new car). You will also need a small probe with a magnet on the end for holding onto the bolts.

Check your PM for some info.

843de

You're correct that a special GM tool is required, and I can't recall anyone here changing theirs out as a DIY project.

There are some access issues, and the techs I've talked too indicate the job takes about three hours "on a good day", the rest of their opinions of the job are too salty for the forum.

You may be better off letting your dealer or a trusted mechanic do the job, sometimes these Ecotec engines aren't too user friendly.

843de

Just when I say I can't recall someone doing it, I should have guessed you'd tackled it already Don.

donbrew

Seems like we are always typing at the same time!

It did only take about 3 hours and 2 beers to do the job.

843de

Great minds and all that, at what mileage did yours go?

My '06 is nearing 200,000 and the panel is at 219,000 so I'm keeping an eye out for leakage.

geezer

Don, was the water pump you changed making noise? and did it take you several hours?

donbrew

Mine started leaking from the top mounted weep hole enough that coolant was needed regularly, no noise. It was on my replacement Junkyard motor, so hard to say mileage wise. I have become convinced that most of the "disappearing coolant" questions are due to the design of the water pump; the weep hole is at the top and in a well, so you really have to be looking for it.

I forgot that you will also need a 1.5 inch bolt (#10, I think) to cut the head off of to make a pilot out of. Do that before you start!

It was only about a 3 beer job, including 1 to clean up. Not a real big deal, except for lining things up. You do have to remove the T-stat housing and the pipe, you should get new rubber grommets. Rebuilt pumps usually come with the pump gasket, new ones don't, so less money gets you more product. Shop around for the tool, if you have time; they can be had cheaper than $50, (I needed one by tomorrow!). Search ecotec water pump tool.

Making noise MAY be timing chain and/or tensioners; pay somebody to do that job!!!!!!!!

donbrew

The thing is; the weep hole is in a well at the top of the pump. DexCool does it's job of coagulating, and it sprays onto the hottest parts of the engine so leakage is hard to find. Not like you old short block.

geezer

Hey, thanks Don, you have been a great help. I believe you might be right. I think it might be the timing chain and or components. I am an old school guy so don't believe that I will tackle the timing. I am just finishing a 1980 blazer hoping to get it on the road soon. Paid little up front but have a small fortune in it now and still have things I want to do!
Thanks again!