sunsrzr

My son has supercharged 1996 Z28 with around 50K miles. He recently had the car start to overheat on him and when I got there it was boiling over a little. I refilled the coolant (it was VERY low) and when he started it, it was leaking horribly at the front of the block. I refilled it again with water and when he started it this time the coolant started to pour out of the radiator (cap off). I tried to purge the air but since it was dumping so much coolant I stopped. I used a pressure tester and the leak was coming from both gaskets on the water pump, badly from the driver side. I did a oil analysis and shows no coolant in the oil and it didn't smoke. I have the car apart right now and am replacing just about everything on the front of motor but am really getting nervous that the head gaskets may be bad. Don't want to get this back together and have to do it again.

Can a really bad water pump cause pressure in the radiator? I believe I got the air out on the bleeders but like I said stopped because it was leaking so bad. Ideas? Thanks for the help!

ahritchie

iTrader: (1)

Yes, bad waterpump WILL make it overheat quick and the pressure will escape at the weakest point. I would strongly consider upgrading to an electric water pump, better cooling, adds 5-10HP, and you can run it with the engine off to cool it off between runs if he takes it to the drag strip.

sunsrzr

I am going to sell the car as soon as I get it back together, just want to make sure it is good for the next owner. I'm putting WAY too much in this as it is (Opti, water pump, plugs wires, AC compressor, radiator..... and the list goes on and on). Funny how every time I look something else needs to be replaced.

shbox

Once the thermostat is open, coolant is going to eventually come out of the radiator neck if the cap is off. That's normal, because it is not the highest point in the system.

sunsrzr

Ok, thank you for the advice! I'll get this thing back together. Man the guys that designed this thing need their heads examined. I've never worked on a car with such little room and having the $500 distributor under the water pump?? Such a great idea

ahritchie

iTrader: (1)

Yeah, an 18 year old car is definitely a mechanic's special Don't get the opti wet when you take the WP off!

sunsrzr

The cap and rotor was pretty corroded and rusted, I'm sure the water pump leak was great for it. Car put down 331 on the dyno when I bought it. They said the plugs and wires needed to be replaced because it was off on the higher RPM's (original plugs and wires from when the SC was installed when new). When I pulled them they were gapped at between 70-75, Vortech says 32-34! Plus wires were pretty bad as well, #8 contacts at plug and opti burnt.

sunsrzr

I'm replacing the opti just because I don't want to pull the supercharger off again. Looks like it's been wet.

sunsrzr

If I install a 160* stat, would I need to have it tuned differently?

shbox

You don't have to, but it is often helpful to also lower you fan ON temps. You could possibly add some timing, as well.