351W overheating
Thread Starter
|
Freshman User
Joined: Mar 2002
Posts: 29
Likes: 0
351W overheating
Good Day,
I've completed the installation of a new 351W in my 82 2WD F150. The truck has a C6 Transmission and a 3 Core Rad. I replaced the Thermostat a couple years ago with a 180 degree one. The previous motor was notorious for overheating and as a result I installed a manual temp gauge. It appears the thermostat is working correctly, the temp gets to about 195 F and then starts to drop quickly down to about 180.
In the city the new motor isn't bad on the heat, unless I really pound on the gas and you can see the temp rise. I've taken it for a longer highway drive and was shocked to see the temp peg well passed 200F. I had to baby the motor under 1500 RPM to try and cool down the mess. The rad is older and I don't when it was installed, but it doesn't appear to leak. The water pump is a reman and less then a year old. All the hoses were replaced when I replaced the pump.
when I added antifreeze to the motor I left the temp guage sensor out of the hole and filled the rad till the intake overflowed. I've noticed some of the fluid from the coolant overflow has been 'sucked' back into the rad. I don't believe I have any air pockets in the block.
I should have looked for a casting date on the block before I installed it, but I would guess it's a later date. I understand if a later 351W is overbored too much it will result in over heating problems ?
Before I replace the rad what else should I be checking ?
How hot should a 351W run ? How hot can I safely run it ?
Monza
I've completed the installation of a new 351W in my 82 2WD F150. The truck has a C6 Transmission and a 3 Core Rad. I replaced the Thermostat a couple years ago with a 180 degree one. The previous motor was notorious for overheating and as a result I installed a manual temp gauge. It appears the thermostat is working correctly, the temp gets to about 195 F and then starts to drop quickly down to about 180.
In the city the new motor isn't bad on the heat, unless I really pound on the gas and you can see the temp rise. I've taken it for a longer highway drive and was shocked to see the temp peg well passed 200F. I had to baby the motor under 1500 RPM to try and cool down the mess. The rad is older and I don't when it was installed, but it doesn't appear to leak. The water pump is a reman and less then a year old. All the hoses were replaced when I replaced the pump.
when I added antifreeze to the motor I left the temp guage sensor out of the hole and filled the rad till the intake overflowed. I've noticed some of the fluid from the coolant overflow has been 'sucked' back into the rad. I don't believe I have any air pockets in the block.
I should have looked for a casting date on the block before I installed it, but I would guess it's a later date. I understand if a later 351W is overbored too much it will result in over heating problems ?
Before I replace the rad what else should I be checking ?
How hot should a 351W run ? How hot can I safely run it ?
Monza
Elder User
Joined: May 2004
Posts: 506
Likes: 0
From: Edwards Air Force Base
Originally Posted by Chevy_Monza
Good Day,
I've completed the installation of a new 351W in my 82 2WD F150. The truck has a C6 Transmission and a 3 Core Rad. I replaced the Thermostat a couple years ago with a 180 degree one. The previous motor was notorious for overheating and as a result I installed a manual temp gauge. It appears the thermostat is working correctly, the temp gets to about 195 F and then starts to drop quickly down to about 180.
In the city the new motor isn't bad on the heat, unless I really pound on the gas and you can see the temp rise. I've taken it for a longer highway drive and was shocked to see the temp peg well passed 200F. I had to baby the motor under 1500 RPM to try and cool down the mess. The rad is older and I don't when it was installed, but it doesn't appear to leak. The water pump is a reman and less then a year old. All the hoses were replaced when I replaced the pump.
when I added antifreeze to the motor I left the temp guage sensor out of the hole and filled the rad till the intake overflowed. I've noticed some of the fluid from the coolant overflow has been 'sucked' back into the rad. I don't believe I have any air pockets in the block.
I should have looked for a casting date on the block before I installed it, but I would guess it's a later date. I understand if a later 351W is overbored too much it will result in over heating problems ?
Before I replace the rad what else should I be checking ?
How hot should a 351W run ? How hot can I safely run it ?
Monza
I've completed the installation of a new 351W in my 82 2WD F150. The truck has a C6 Transmission and a 3 Core Rad. I replaced the Thermostat a couple years ago with a 180 degree one. The previous motor was notorious for overheating and as a result I installed a manual temp gauge. It appears the thermostat is working correctly, the temp gets to about 195 F and then starts to drop quickly down to about 180.
In the city the new motor isn't bad on the heat, unless I really pound on the gas and you can see the temp rise. I've taken it for a longer highway drive and was shocked to see the temp peg well passed 200F. I had to baby the motor under 1500 RPM to try and cool down the mess. The rad is older and I don't when it was installed, but it doesn't appear to leak. The water pump is a reman and less then a year old. All the hoses were replaced when I replaced the pump.
when I added antifreeze to the motor I left the temp guage sensor out of the hole and filled the rad till the intake overflowed. I've noticed some of the fluid from the coolant overflow has been 'sucked' back into the rad. I don't believe I have any air pockets in the block.
I should have looked for a casting date on the block before I installed it, but I would guess it's a later date. I understand if a later 351W is overbored too much it will result in over heating problems ?
Before I replace the rad what else should I be checking ?
How hot should a 351W run ? How hot can I safely run it ?
Monza
While a bad leak will often "bloat" your radiator hoses, hair line leaks sometimes don't show this classic symptom. The easiest way to find out is find a reputable friendly mechanic that has a "sniffer" and have him check your radiator out. Many will do so for free but not all have "sniffers" so try a radiator shop if no one else has one.
A Sniffer test is quick and painless. Just take the radiator cap off, start the truck and then put the hand held sniffer up to the hole where the cap was. If the head gasket is blown in the way I think it is, it will detect exhaust gas in the coolant and squeel.
Most will do this free but even if they charge, it shouldn't be more than a couple bucks as it only takes 2 minutes to do.
========
A doubt it is fan or shroud related since it did it at highway speeds thus you should have had good air flow even without a fan or shroud and I doubt it is Thermostat related if it cools down on it's own at low RPM. Same reasoning for a bad radiator or water pump, it wouldn't cool down at any RPM if it were one of those.
I would be interested in knowing what it was if it wasn't a head gasket or warped head as I don't see what else it could be. I had a Triumph 6 cylinder that did this all the time and after fixing it, still would pop back every couple years or so. Some are just possessed. I got really good at changing that gasket by the time I finally got rid of that car. -gggg-
Good Luck,
Lee
Last edited by Lee Lichterman; Aug 27, 2004 at 10:21 PM.
