Bad Overheating Problem in C4

I haven’t managed to find out what is causing the overheating. I was driving down the road when my water temp shot up to 290. I pulled over and popped the hood. The coolant reservoir was overflowing and boiling. I let the car set and cool and started back to my home. I was going 55mph and the car temp kept increasing. I pulled over again and waited 30mins. I managed to get back home safely with a temp of 170. The next day I went and tried to find out the problem was. The first thing I did was check the radiator. I figured it was blocked since as I drove, the temp still increased. The radiator was clean and unblocked. I then started up the car and let it idle. The cars temp increased fast. Both fans kicked in but they effected nothing. After a while, I heard a high-pitched whining noise. It was the water pump. I figured that was it, the water pump must be broken or breaking. I replaced the pump along with the thermometer. I let the car idle again and it stayed around 230. I then went for a drive, as I drove, the temp started to decrease. One thing I noticed though was the analog water temp gauge seemed to be broken, it went past 260 and stayed there, also when I started the car up, both fans started running and didn’t turn off. The car seemed to run fine as I drove. Near the end of my drive though, the temp hit 150 and stopped. I pulled into my drive and popped the hood. It was boiling again, steam coming from both the reservoir and engine this time. The thermostat stayed at 150 though. It never increased or decreased. I believe the problem may be the radiator but I might be wrong


2 thoughts on “Bad Overheating Problem in C4”

    1. You say rad. was cleaned, did you remove it and clean all the cooling fins for good air flow and flush core for good coolant flow? Did you use LT1 type thermostat to replace old one? LT1 reverse flow thermostat are dif. than standard type. Was system clear of air in coolant=bleed air out?

Leave a Reply

Your email address will not be published. Required fields are marked *