97silverslpss

With the car at operating temp I drove 40mph for several minutes. Came to a stop sign and after pulling away I notice the temperature gauge very close to the red. I have put 5k miles on the car with the temp gauge never getting above ~180.

The front air dam is in place and not broken, thermostat opens in 160 degree water and radiator cap holds 18psi.

When following shoebox’s instructions for filling the coolant system coolant slowly comes up and out of the radiator filler neck. This will go on for a few seconds then a couple of bubbles come up and the level drops down an inch or so only to come right back up again. I don’t ever get the good burp of bubbles and coolant movement that I have seen both times I have done this procedure. The car will get up to the red before I feel like I have all of the air out.

I had heat before it overheated on me, now I have no heat at all. I think my only options are bad water pump or obstruction in the coolant system. How do I check these?

mrmint69

There is a weep hole on top of the water pump that will loose coolant when the bladder fails. I know the heater cores can get clogged on these easily. There is a way of flushing it out, but its been years and I can't remember exactly.

97silverslpss

I have seen the procedure to flush the heater core and that will be the next thing I do. I owned another LT1 long ago that the wheep hole started leaking when the water pump failed. Mine is not leaking at all it just looks like there is no circulation.

I recently read that the water pump drive shaft can strip out and that would not be indicated by the wheep hole leaking. I guess the only way to know is to pull the water pump off.

JCSWS6

I had a stripped water pump drive on mine when I did my cam. I didn't even realize it but I would have known it pretty quick if I had kept driving. I changed to an electric an will never look back. I can now trouble shoot my cooling system with the car off.

My ideas:
Open the radiator cap, if the system is flowing water you should see water flowing into the radiator from the crossover tube (fitting just under the overflow). Of the water isn't flowing you know what you need to do. If it is same thing.

Are you positive the thermostat is opening? (boiled in water or ran the car without it)

97silverslpss

I dropped the thermostat in hot water several times. It opened and closed every time.

That is whats missing, with the radiator cap off, there is no coolant moving from the crossover tube at all. And there is a strange soft squeeling noise that wasn't there before.

I just wanted some confirmation before I yanked the water pump off. I hope the noise is from the shaft that has worn out. I am going to pull the pump tomorrow and see what it looks like.

97silverslpss

Wait… what strips out here? The water pump portion of the drive, or the camshaft portion?!?! Expensive and lots of work? or cheap and easy??? (please be cheap and easy, that how I like em)

JCSWS6

Mine was worn on the coupler and block portions thats why I went EWP. I considered a new drive but with half the splines gone on the engine side I wouldn't trust it. I was dead set against doing an EWP but after looking at what all I would need to do to make the factory set up work right it was a no brainer. Best deal I found was jegs brand EWP for $172, get the relay kit and its a quick job!

97silverslpss

I suppose either could wear out, but it looks like the coupler and block is most common. Expensive and lots of work, I should expect nothing less. But If that is the case I am going EWP. Thank you

6SpdLT1Z

Are you running the stock fan temps? If you're running a 160* tstat you should probably have the fans kick on a little earlier too. Are you sure the fans are coming on? Check shoebox's page for the appropriate tempatures for them to kick on.

The front air dam doesn't just have to be there. Look under the car and see if there is debris blocking airflow to the radiator. Sometimes a bunch of leaves can get up in there and you'll want to clean that out.

Make sure you've got a good mixture of 50/50 coolant and make sure the air is bled out of the system. It can be a pain to get all of the air out, but I really feel like 95-100% of cooling issues can be resolved via shoebox's webpage.

Hope some of this helps.

97silverslpss

Turns out the bearing on the back of the WP failed and the increased friction cause the coupler splines to wear out. Does anyone know if the coupler is readily available? A quick look on ebay returned a handful for $50... I am leaning towards EWP.

JCSWS6

My local dealer could get me one overnight for about $50 (still GM stocked). If the splines on the motor side are good this and a new water pump will get you up and running. For me my motor side splines were chewed up a little so for the price of a water pump and the drive I just went EWP.

I was hesitant about the EWP but got the relay kit and could not be happier with it!

Matts97camaro

Seems like you left out a step. Have you tried using the bleeder valves after slowly filling the radiator. This
burps the system of air and is a must for proper cooling. After filling the radiator I will run the car for a minute or two, then check and add more water to the radiator. When I am certain the radiator is full I will start and run the car till the thermostat opens, after it opens then I use the bleeder valves you can hear the air escaping, then a small stream of water will shoot out, thats when you tighten the bleeder valve. The engine is running when I do this procedure. For proper engine temp and performance this is a must. Air in the cooling system can cause all kinds of problems.