Really was no idle per se involved, maybe 15 seconds before I turned it off. I'll check the fan first chance I get.Nice gauges!
The cooling system is not complicated. When driving, you have good air flow through your radiator, but not at idle. Is there something wrong with your fan?
Thanks Tom, it was an NOS GM/AC Delco (RC27) I picked up, shows a 15lb pressure rating. Doesn't mean it isn't faulty though. Think a new cap, thermostat, and fresh coolant are a good idea.When you shut the motor off and then lose antifreeze you need to check your cap. Happened to me on my boat. 1 motor fine the other overflowed. Switched caps first because I did not believe this old guy. That was in 1990. Guess who is the old guy now. Needs a 15lb cap. Make sure antifreeze is 50-50 or less.
Radiator may be stock for the the vehicle, came with it when I purchased... VIN says it was originally the 307ci V8, so might need to go bigger. But, this overheating on shutdown is new, have not experienced it before the last 2 times I took it out for short local drives. I'll check out the fan and clutch first chance. Thanks for chiming in.There's a lot to this story, looks like a Dakota Digital dash, (I love mine btw) and I see you are running a 325hp 350 according to your profile? If I remember right a small block Chevy likes around 180-190 max temps while running. When the motor shuts off the coolant stops circulating so the hot iron keeps giving up its heat raising the coolant temp. I'm thinking your cooling system might be right on the borderline for enough cooling effect for your motor. I would start with the usual suspects. Fan clutch have enough tension? Next might be radiator? Does it have any restrictions? Capacity? Thermostat might be a bit high, maybe it's a 190 and a 180 could make a difference? A cooler thermostat may not work if the radiator is at minimal efficiency? I don't know your setup so these are really open ended questions so take this as an inquiry. The more info the better the diagnosis. My LS engine is happy in the 200-220 temp range here in Texas too. No boil overs but I am running a radiator rated for 800hp so my measly 400 doesn't even make it sweat. Hit us up with some details and hopefully someone will hit the nail on the head for you!
PO put a cool dude 6 blade stainless fan, no clutch, but a 3" aluminum spacer. Shroud is in great shape, maybe the fan should be deeper in. Replace with clutch fan?let's see some pics of the underhood setup with shroud, fan, coolant overflow tank
I had similar problem waiting in line at not so fast food Burger King in 90°+ weather. With air on and at idle In gear it started climbing. Changed thmostat, coolent flush.......seems to run cooler by 5 or 10° but it's also cooler outside. We'll see how she does nx week out of town at Gainesville for the NECOA meet and Saturday country cruise.Thanks Tom, it was an NOS GM/AC Delco (RC27) I picked up, shows a 15lb pressure rating. Doesn't mean it isn't faulty though. Think a new cap, thermostat, and fresh coolant are a good idea.
Have not looked, but engine temp is about 195 when driving at 2000rpm, so assume it's mostly working. The problem occurs at idle/shutdown.some thoughts.....
-is that cool dude fan actually pulling air thru at higher rpm's? or are the blades flattening out?
I'd have to look at the build sheet, but it's a fairly recent crate motor our of Denison, Texas.-is that the original water pump? how old?
I'll take a look at water flow, had not done that yet. No idea on the age of the radiator, may be original to the vehicle, which had a 307ci in it. The crate motor is a 325hp/350 bored .030 over... may not be enough radiator, but this boiling over at stop is new.-when you first start up, take the radiator cap off to look inside. how does the water flow look? maybe a clogged radiator? how old is the radiator?