Well, I had a FAST 78mm intake manifold install on my car today by a performance shop, and when they put it on the dyno it only got 302 RWHP and 322 ft-lbs with 71* weather, which is strange since I got it dynoed in august and it got 306 RWHP and 317 ft-lbs. That made me really bummed, and the guys at the shop said that my engine was probably running lean, and that I would need a tune, and that I should not race my car at all as to avoid melting a piston. After I drove home for about 2 miles, I noticed that my engine thermostat was going up higher than normal, around 220*, and my electric fans were blaring, which was odd to me since it was pretty cool out and I hadn't been driving hard at all, so I pulled over into a neighborhood and popped my hood to check for any leaks or anything obvious, I couldn't find anything, besides that my air lid wasn't on securely. I went back into the car, and my thermostat was up to 240* just idling. I immediately turned my car off and called up my brother, who is a bit more knowing about cars. I brought over a jug of water and we poured it into the overflow, in case I was low on coolant, since I had to have the LS6 coolant lines put on to fit the intake. The temperature was back down to 210* when I started the car, and it stayed there for a minute, so we figured it would be safe to drive home, but on the next 2 miles on the way home, the same thing happened. I'm kind of freaking out since I don't have any money left after paying the the intake and install, and I just bought a new stereo for my car yesterday, so I am pretty broke. anyone have any ideas? I've been reading about head gaskets going bad, and I'm really hoping that isn't the case. I'm taking the car back to the shop tomorrow for them to look at it.

 

How was the coolant maby the shop drained it and never filled it back up ? that would be my guess.

 

it seems like something is up with what the shop did. you dont want to put just water it, that wont keep it cool. you need to fill it with a dilution of 50% dexcool and 50% DI water. you should check the level and see, ill bet they drained some of it, but if they drained it all you have been running much hotter.

 

When I did my heads it started to over heat and it was a matter of less half a gallon that made all the diffrence and yes it should be a mixture but water will save you if emergencys or if you want to add a little to top it off.