: overheating, waterpump? 2002 deville w/ 120k miles



house
09-30-07, 04:30 AM
I have done a gasket fix in a bottle a month ago, and tested the car in the garage for a week and everything was fine.

well now the car overheats, but the radiator stays cold. I tried a new tstat, same problem. if the air in the cabin is hot, it will fix the problem, however the air barely gets hot anymore, sometimes a little warm.

I believe the waterpump is the culprit,
I disconnected the hoses and ran a hose from the tstat housing (with no tsat) into a bucket and no water was pumping out. I also drove around with no tstat, and would overheat, but the radiator would stay cold. water would boil over, etc . I checked for clogs and didnt find much. I took out the radiator (which has a sticker on it that says it was made 5/2006 btw) and flushed it, some of the gasket fix crap came out of it.

I took off all the stuff to get to the waterpump, however it looks very new, and its very firm, not wobbly etc. I removed the tension on the belt, and the waterpump spins very nicely, and quietly. however it wouldnt even pump any water into a bucket??

So, I am not sure if I should install a new water pump or what, I am running out of ideas. I tested the system for 6 hours today with various scenarios, and tomorrow I will buy some clear hose to see what exactly is going on before and after the radiator (Which I am pretty sure isnt clogged).

how sensitive is this system? the car ran fine with no tstat, besides the eventual overheating. I know cars need tstats, however I was just trying to remove any variables. does the water pump need a tstat to operate? I see it as a mechanical part that will pump water no water what.

lastly, how can you test or tell a waterpump is bad w/o removing it, or after removing it?

also what is the proper way to add coolant to bleed the air out? do u just watch the tank until all the air bubbles go out, or do u pour coolant into the rad. hose that goes into the engine and rad?
thanks

MM STS
09-30-07, 09:27 AM
lastly, how can you test or tell a waterpump is bad w/o removing it, or after removing it?

also what is the proper way to add coolant to bleed the air out? do u just watch the tank until all the air bubbles go out, or do u pour coolant into the rad. hose that goes into the engine and rad?
thanks

I've always added coolant to the radiator directly. The pump not moving water sounds to be your problem. Either the coolant can not get to the pump or the pump is not working. I'd look for a blockage to start. Maybe also try to fill the pump if you can and see if it is ejected. People have blown head gaskets (very expensive) overheating there N* motors. Mike

Ranger
09-30-07, 11:13 AM
You have air in the system. Make sure that the purge line is clear and flows coolant at idle and it will bleed itself. It is the 3/8" line that runs from the pump to the surge tank. Remove it at the tank. Probably clogged it up with that "repair in a bottle", which will not work.

zonie77
09-30-07, 12:13 PM
The only way to check the water pump (for pumping) is to remove it.

If the impeller is tight on the shaft and all the vanes are there is should be good.

Some brands had plastic vanes that broke or wore out and rarely a metal one will come loose from the shaft.

If the seal was bad you would get an external leak.


I think Ranger is right that the purge line may be clogged. That is what purges the air out of the system. If that checks OK you'll have to pull the pump to check it.

house
09-30-07, 03:16 PM
I checked that purge line, by blowing air in it with my mouth and I watched the coolant at another part of the engine go up and down as I was blowing,


also, when i tested the radiator with hot water, it became warm everywhere, not just in some spots, so I am pretty sure it isn't clogged.

any other sugestions before I replace a like new looking pump?

Ranger
09-30-07, 06:04 PM
Test the coolant for exhaust gases.

house
10-01-07, 12:35 AM
even if the HGs leaked, it doesnt explain the problem of the coolant not flowing


so anyways I put a new pump in today,and a new tstat. i test drove it for 25 minutes, and it was perfect! i havent seen it this good in a long time


however, later it overheated again! i checked, hot hoses, cold radiator. whats making the coolant not go in the #%#$% radiator!!?? no clogs in the purge, no air bubbles to my knowledge, radiator tested fine for me in the sink, was all warm and didnt notice clogs

please help
thanks

zonie77
10-01-07, 02:06 AM
Like Ranger said, test the coolant for exhaust gases. If you have a Head Gasket leak it's putting "air" into the coolant.

zonie77
10-01-07, 02:07 AM
Have a radiator shop do it. They are usually quicker and cheaper than a mechanic.

Ranger
10-01-07, 05:25 PM
even if the HGs leaked, it doesnt explain the problem of the coolant not flowing

Zonnie pretty well explained it.

If you have a Head Gasket leak it's putting "air" into the coolant.
And water pumps do not pump air.

house
10-02-07, 02:07 AM
thanks

I was going to rent the pressure tester to see if the system holds steady pressure but the tool was rented by someone else

still trying to find a place to test the coolant for exh gases

anyways today, right before the highway onramp, it overheated, however once i got on the highway, it cooled to reg. temp, and ran fine for 15 mins,
later it ran fine for 20 mins, and 2 hours later it ran at reg. temp for 30 minutes

it seems fixed ( lol, yarite)

why is this so inconsistent? aggh

zonie77
10-02-07, 10:30 AM
Initially the gasket still has some tension. Imagine a HG torqued to 20ft lbs...It holds some pressure but it's always on the threshold to leak.

The low pressure coolant tester (15 psi) won't show the leak.

Get the exhaust gas test done.

sannerj
05-01-13, 05:00 PM
house,, let us know how this turns out.. im having the same/like issues.. most appreciated

Submariner409
05-01-13, 05:38 PM
This thread has been dead for 6 years. Nothing wrong with resurrecting an old thread, but when half of the respondents - including the OP - haven't even been in the site for years, your chances of a reply are slim and none.

Go up a few inches and read the sticky posts - lots of cooling system info there......... and there are many more, more recent, threads on cooling system maintenance and problems than this one.

Set your profile preferences to show latest threads first - that way you see the latest and greatest as opposed to the dead and gone.

Manic Mechanic
05-02-13, 11:04 PM
Notice he didn't mention the old pump having a loose or disintegrated impeller when he replaced it, and the new one made really no difference, therefore his head gasket seal was blown as others were telling him. He bailed on the car. If you're having the same symptoms your engine needs major repairs. You can bail or start a NEW thread with your cars relative specs, ie. mileage, condition, how much you value it etc. Also how much you're willing to spend in time and money to fix it back to right, what kind of repairs you are capable of doing yourself, and where you are generally located like city and state. Then we can tell you if we think it's worth it, how much you should expect to spend in time and money, and who you should look into taking it to or where to start if you do it yourself.

Vernon