94 1500 running 230deg contantly

chevyracer8262 · 06-20-2009, 04:46 PM

What would cause a 318 in a 94 1500 to run about 230deg constantly? I have just finished rebuilding the transmission and got ready to reinstall it and found out that one of the freeze plugs were leaking so when I removed both of them I found that the driver side of the block had a fair amount of rust in it and I raked out what I could get which was about enough to fill a 1/4 measuring cup with. I'm thinking that with it running that constant hot temp that there's got to be a restriction in it somewhere, probably due to the rust. Also the heater is not getting no where near as hot as it should be especialy with the water temp that high Especialy since the water pump, thermostat, radiator, radiator cap and hoses are relativly new (most replaced less than a year ago except the thermostat just replaced it today) I just got finished running some prestone radiator flush through it, and getting ready to go flush it out. What would be the best way to try to remove the rust from the system? I noticed on the bottom of the block that there are 2 plugs going into the water passages on the front of the 2 forward freeze plugs on the side of the block. Can I remove one of these plugs and run the water hose in the radiator while the engines running to get out the rust or what? What's the best way to flush the system?

gmctrucks · 06-20-2009, 06:25 PM

I have flushed my heater core by removing the hoses then I run some water though it. Now how I flush my engine before I replace my antifreeze I remove my lower rad hose and just place the water hose on where the cap goes and I let it clean out good. Then I shut the truck off and flush my rad with the running water. I know Prestone has some rad flush that it's a power but I wouldn't use the whole can and also flush it out good because it's strong stuff also maybe all the rust clogged that new rad.
Good luck! GMC
PS-Also check your fan clutch for signs of oil. Also when one freeze plug goes out there all ready to be replaced been there done that and I learned the hard way.

06-20-2009, 04:46 PM	#1
chevyracer8262 Senior Member Join Date: Jul 2008 Location: Mississippi Posts: 144	94 1500 running 230deg contantly What would cause a 318 in a 94 1500 to run about 230deg constantly? I have just finished rebuilding the transmission and got ready to reinstall it and found out that one of the freeze plugs were leaking so when I removed both of them I found that the driver side of the block had a fair amount of rust in it and I raked out what I could get which was about enough to fill a 1/4 measuring cup with. I'm thinking that with it running that constant hot temp that there's got to be a restriction in it somewhere, probably due to the rust. Also the heater is not getting no where near as hot as it should be especialy with the water temp that high Especialy since the water pump, thermostat, radiator, radiator cap and hoses are relativly new (most replaced less than a year ago except the thermostat just replaced it today) I just got finished running some prestone radiator flush through it, and getting ready to go flush it out. What would be the best way to try to remove the rust from the system? I noticed on the bottom of the block that there are 2 plugs going into the water passages on the front of the 2 forward freeze plugs on the side of the block. Can I remove one of these plugs and run the water hose in the radiator while the engines running to get out the rust or what? What's the best way to flush the system? __________________ Chevyracer8262

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
TBI running rich	1BigAmerican	Chevy Truck Forum	4	11-04-2008 08:27 AM
99 gmc not staying running	runnrich	GMC Truck Forum	12	04-11-2008 06:17 PM
'90 G20 5.7L Running Bad	Kingcool	Chevy Truck Forum	2	01-31-2008 03:15 PM
running Bad	stryder	Dodge Truck Forum	0	12-17-2005 07:26 PM
Running from Hurricane!!	ladutjr	Off-Topic	3	08-30-2005 10:15 PM

06-20-2009, 06:25 PM	#2
gmctrucks Senior Member Join Date: Nov 2006 Location: Houston,Texas Posts: 3,945	I have flushed my heater core by removing the hoses then I run some water though it. Now how I flush my engine before I replace my antifreeze I remove my lower rad hose and just place the water hose on where the cap goes and I let it clean out good. Then I shut the truck off and flush my rad with the running water. I know Prestone has some rad flush that it's a power but I wouldn't use the whole can and also flush it out good because it's strong stuff also maybe all the rust clogged that new rad. Good luck! GMC PS-Also check your fan clutch for signs of oil. Also when one freeze plug goes out there all ready to be replaced been there done that and I learned the hard way.