the cooling problems continue ...............last week put my 95 in a shop to replace a WP that was going out and found out the bearings were shot so it needed replacing anyway but that's not the problem.

Had a very helpful vette buddy attempt to drive the car from the shop to my home but in route and a mile down the road the car heated up to I think 245!! so not to ruin the motor pulled the car off the road and noticed coolant puking out of the recovery tank!

Needless to say it had to be towed. We got the car to a residence
and did some testing. The knock sensor was pulled and clean coolant came pouring out so we knew that area was not clogged. Further testing kept pouring fresh water thru the system and sometimes it would bubble up thru the upper black tank. so we played with the air bleed screw to let air out , sometimes just air came out then other times water, I think the last attempt we got water to come out.

Further more were concerned that the new WP was not circulating but did see water swirling thru the upper tank so assumed it was doing its thing. that's where we stopped and am still trying to figure out what the problem is! ofcourse thiers more to the story so keith might add what he thinks, but were thinking something is clogged somewhere along the line causing it to heat up before and after it went to the shop, however the serious problem started when the car started puking coolant which it had never done. so $350 down the drain to the shop for the WP install and coolant flush and the problem still exist!

 

I have to wonder if the coolant puking from the overflow was foamy or was it completely liquid. If it was foamy you most likely have a head gasket leak. Happened to my 84 that way.

 

Just some thoughts here. Have you checked to insure that the radiator is clear of junk? Is the internals of the radiator clear or plugged? You can check that with a digital optic thermometer. Some people feel the thermostat can be an issue and drill a small hole in the lip to allow air to pass through even when the thermostat is closed. Are you sure they put on the correct water pump? Some are reverse rotation while others aren't, AFAIK externally they look the same.

Just some thoughts.

 

Hopefully the shop that replaced the water pump also transfered the water pump drive to the new pump.

 

OP - Why wouldn't you have towed this car to the shop? I don't understand the self-diagnostics and the tow to somewhere else.

You mentioned 1 mile so I guess that was maybe from "home" and not 1 mile from shop. Just a bit confusing.

 

Are the fans coming on?

It sounds to me like they may have put the T-stat in upside down or there was still allot of air in the system. LT1's can be a challenge to get the air out.

 

Honestly, and this is from my experience the first time I replaced my water pump on my 95, it sounds to me like they (the shop)didn't know the proper full method on the lt1. I didn't the first time, and by the time I got two miles from home I had the same symptoms you describe. It's not a hard procedure, but it needs to be followed. Look up cooling system full procedure for c4 lt1. If they didn't burp it right there is an air pocket at the gooseneck that keeps water from flowing when it heats up.
There are few moving parts, as long at the tstat opens and the pump turns, I'd say that this is the problem. Just my experience.
I've wondered often how GM filled these things on the line and they didn't blow up, but I guess they had a way. Hahaha
Good luck

 

forgot to mention both fans are coming on...

 

thanx for the replys............ heres the history in chronical order.

before I took it on the shop and changed the WP the temp was heating up and would max out around 226 then id get on the hiway and it would calm down to around 203-4 but I would also turn the AC and it would drop.

The coolant only started puking after I got it back from the shop where they replaced the WP, the guy who did the install had screwed up several times infact the shop owner even got involved!!

anyway am starting to think something went wrong with the install and the guy who installed the WP was not that experienced with corvettes but at first insured me everything would go just fine. were not out of the woods on this one yet!

 

thiers a very good chance of that and I rememeber the shop owner mentioning he found a sleeve but didn't know if it was the new or old one.

would that matter????

 

complety liguid

 

The rad problem is our last suspect

 

cuzz the car was running ok when I drove it to the shop, the puking happened about a mile from after I got it back from the shop

 

Hmm, what worked prior and what was 'fixed' by the hack? Wasn't the radiator!

 

I would go back and get that part. Then check to see if it is the water pump coupler. Here's a link to what it should look like.

http://www.ebay.com/itm/Chevrolet-Co...-/231055233983

Then check with them to see if they ordered a new one for your car as my replacement water pump did not come with one and I highly doubt if any replacement water pumps come with one. If they didn't order one, there's a pretty good chance your pump impeller isn't spinning.

 

Either the coolant level wasn't correct after the pump replacement of the pump is not engaged. If you see circulation, then it must be the former. By the way, 226 degrees is not hot.

 

I believe circulation was taking place, cuzz we emptied out the coolant after we got it to the house and ran water thru the system, however as the car was running you could see bits of coolant moving thru the water at the upper tank

 

Maybe they didn't fill the system. Have you tried running it since the initial overheating incident?

 

This is completely normal... hope you haven't wasted your time & money

 

I am the one trying to help Dan. This is what I believed has happened.
The car was overheating. Dan took it to a shop and they told him the waterpump was leaking.
Dan bought a waterpump and took the car to what seems to be a good shop and told them to replace the waterpump, which they did. The old pump was missing some of the ball bearings and was starting to leak.
The mechanic said they bled the system, etc. on filling it. I looked at the front of the radiator and there was no buildup of leaves and dirt on the front of it.
I started home with the car and noticed the digital temp started climbing. When it got to about 235 I turned on the A/C and the temp dropped fairly quickly to about 221, then started climbing again. I found a gas station to pull into and the digital temp was 245.
At this point coolant was coming from the overflow tank, which I am not concerned with as I noticed it was almost full before I started the car, which was cold.
After getting the car towed to my house I decided to take out a knock sensor to see what it was like inside the block. Clean coolant came out with no evidence of a bunch of crud in the system.
We refilled the car with water, fired it up and added water as the level went down in the black pressurized tank. The cap was off. I opened the bleeder screw and got a lot of air out. Finally I got water coming out.
The temps climbed to 229 and the fans came on low. The temps continued to climb and at 236 the fans kicked onto high. The temps did not go down but did not go higher either.
After shutting the car off and letting it cool we checked the water level in the pressurized tank and it was full. I opened the bleeder and water came out.
I had been filling the car with straight water. What is in the pressurized tank is green coolant, so it appears there is definitely water circulation.
I tried running the car with the pressurized cap off to try and see if there was water circulation, but was unable to do so. As soon as the car warmed up and the thermostat opened the water/coolant mix would shoot out of the tank under pressure, almost constantly, making it virtually impossible to see if there was water circulation.
This is where it now sits.
We got a call from the shop and it seems that they have the sleeve that goes over the shaft before the waterpump is installed. Do new sleeves come with the waterpumps? I do not remember and was not involved with this until after the new waterpump was installed.