94 C4 Overheating
Thread Starter
3rd Gear
Joined: Jul 2022
Posts: 3
Likes: 0
94 C4 Overheating
I am a new corvette owner and previous owner of an NHRA 2002 Trans Am, so this would be my first LT1.
I recently purchased a 94' LT1 and knew it was going to be a bit of work, but after day 1 I'm either missing the "reason for everything" issue, or multiple issues all together. I have the common issues such as my fuel gauge reading incorrectly, though I found it odd that my car smells like it's running extremely rich. It started to smell like everything was burning (No leaks). I know the water pump was replaced as well as optispark. Now onto the issues.
On a cold start, the vehicle will idle as if there is a vacuum leak, revving up to about 1200 and dropping until the vehicle shakes and near-stalls, once I rev the vehicle, there's a bit of a delay, the car "hiccups", revs up, and all is back to normal idling. After driving around for thirty minutes, I noticed my coolant temp was sitting at ~250, at times just barely reaching the line at the 260 mark. This would fluctuate between 240-250. I have no lights on the dash, no codes as of right now.
When getting the vehicle home, it was insanely hot under the hood, I know these vehicles run hot, but this was so hot that after three hours of sitting in my garage, the motor is still too hot to touch. The fans DO kick on while driving, keeping it at a consistent 240-250 while driving it home. The only other thing I noticed is it would appear my power steering pulley is pretty wobbly, feels pretty tight on there but there's a noticeable wobble when the motor is running, maybe the shaft? I've seen someone post in this forum that pulley wobble can be normal?
Coolant levels are fine, though it's definitely boiling in there when the vehicle shuts off for a good thirty minutes or so.
Lastly, my oil pressure will sit comfortably in the mid-section while driving, around that 40-50 mark, and at idle, will sit at ~5-10.
Aside from checking the thermostat and radiator and filters, am I missing one of these "c4 problems" issues? Knowing my fuel gauge is incorrect, is it common for the rest of these gauges to be responding to the drive and just sitting at incorrect numbers, and these lt1's to get this hot and take this long to cool down? Thank you so much for any input.
I recently purchased a 94' LT1 and knew it was going to be a bit of work, but after day 1 I'm either missing the "reason for everything" issue, or multiple issues all together. I have the common issues such as my fuel gauge reading incorrectly, though I found it odd that my car smells like it's running extremely rich. It started to smell like everything was burning (No leaks). I know the water pump was replaced as well as optispark. Now onto the issues.
On a cold start, the vehicle will idle as if there is a vacuum leak, revving up to about 1200 and dropping until the vehicle shakes and near-stalls, once I rev the vehicle, there's a bit of a delay, the car "hiccups", revs up, and all is back to normal idling. After driving around for thirty minutes, I noticed my coolant temp was sitting at ~250, at times just barely reaching the line at the 260 mark. This would fluctuate between 240-250. I have no lights on the dash, no codes as of right now.
When getting the vehicle home, it was insanely hot under the hood, I know these vehicles run hot, but this was so hot that after three hours of sitting in my garage, the motor is still too hot to touch. The fans DO kick on while driving, keeping it at a consistent 240-250 while driving it home. The only other thing I noticed is it would appear my power steering pulley is pretty wobbly, feels pretty tight on there but there's a noticeable wobble when the motor is running, maybe the shaft? I've seen someone post in this forum that pulley wobble can be normal?
Coolant levels are fine, though it's definitely boiling in there when the vehicle shuts off for a good thirty minutes or so.
Lastly, my oil pressure will sit comfortably in the mid-section while driving, around that 40-50 mark, and at idle, will sit at ~5-10.
Aside from checking the thermostat and radiator and filters, am I missing one of these "c4 problems" issues? Knowing my fuel gauge is incorrect, is it common for the rest of these gauges to be responding to the drive and just sitting at incorrect numbers, and these lt1's to get this hot and take this long to cool down? Thank you so much for any input.
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
Remember to always utilize the digital temp display NOT the analogue gauge which is very inaccurate.
Take a good read through this "sticky" at the top of the general info section it may give you some ideas on where to look to get the stock cooling system back to snuff.
https://www.corvetteforum.com/forums...peratures.html
Take a good read through this "sticky" at the top of the general info section it may give you some ideas on where to look to get the stock cooling system back to snuff.
https://www.corvetteforum.com/forums...peratures.html
Drifting
Joined: Jun 2020
Posts: 1,355
Likes: 396
From: Northwest Ohio
Definitely fix that… I imagine that could affect fans turning on. You have two CTS sensors, one for the analog display and another for the computer to use.
Are your fans turning on/running? Does it stay cooler at speed? Sorry I have reading comprehension issues, you answered this. I would definitely check the usuals with the radiator being clogged with debris, new rad cap etc
