C4 Engine Smoke
Thread Starter
Intermediate
Joined: Oct 2014
Posts: 28
Likes: 2
From: Phoenix AZ
C4 Engine Smoke
I have a 93' Vette with 134k miles on it. It holds its own but when it hits 210-220 degrees on the engine temp on idle, it will randomly start smoking from the engine bay. I have also noticed that if I achieve and/or exceed 50 mph and then come to a stop at 210 degrees, it will start smoking. It looks more to be from the upper coolant reservoir. I have not flushed the coolant but have added 50/50 coolant to the upper and lower reservoir and have noticed a change in regular driving temp from 235 down to 220 but the car still smokes. What could it possibly be? Is the upper coolant reservoir cap maybe failing? Should I flush the whole cooling system? Does the 93' Vette maybe have a certain type of insulator that is used for the hoses that may be at fault? Hit me with as many possibilities it can be.
Thanks,
Ray
Thanks,
Ray
Safety Car
Joined: Aug 2006
Posts: 4,147
Likes: 452
From: Port St. Lucie West Florida
Regular driving temp should be approx 195-205. Check the front of radiator for debris ( leaves etc) . The coolant should be changed if it has not been done in awhile. I do not know about your smoking issue
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
When my upper reservoir cap went bad, the lower over-flow bottle would remain filled when it cooled, and the upper reservoir would be low/dry. Replacing the pressure cap on the upper tank fixed it.
One other time I suspected a leak elsewhere, but couldn't narrow it down. AutoZone supplied a coolant temperature test kit that allowed me to pressurize the system and inspect all the connections while the engine was cool. (Turned out to be a bad hose connection.)
Once the hose clamp was dealt with, I was able to pressurize the system to 22 psi ( 7# above the point the 15# cap was rated) and observe the pressure held steady for the 15 minutes I conducted the test. No leaks seen or detected.
Note: I ended up purchasing the tester from AutoZone, which they will allow you to do, last time I checked.
Good luck!
One other time I suspected a leak elsewhere, but couldn't narrow it down. AutoZone supplied a coolant temperature test kit that allowed me to pressurize the system and inspect all the connections while the engine was cool. (Turned out to be a bad hose connection.)
Once the hose clamp was dealt with, I was able to pressurize the system to 22 psi ( 7# above the point the 15# cap was rated) and observe the pressure held steady for the 15 minutes I conducted the test. No leaks seen or detected.
Note: I ended up purchasing the tester from AutoZone, which they will allow you to do, last time I checked.
Good luck!
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
