Minor coolant flush. Now truck runs hot

Here's where I am at...

Drained the radiator via the pet cock. Got about 2 gallons of red coolant out. Ran low on time so I topped off the radiator and overflow tank (I dumped the contents when I drained the radiator) with just water. Light pink coolant/water in the radiator. When I ran up to the parts store I noticed the needle on my temp dummy gauge sitting higher than normal. Between half way and the red. What could cause the temp to increase on such a short drive of about a mile?

The coolant looked pretty fresh still and I have not had any cooling issues before. Any ideas?

I plan to flush it completely with water in the am when I do my water pump.

side note: when I refilled the radiator I left the cap off and started the truck. Turned the heat all the way up to get it circulating through out the system. I was getting foamy water starting to form at the radiator fill. I'm hoping it was just a ton of tiny air bubbles but it looked more like soap.

 

One other thing I noticed is the lower rad hose is almost cool while the top hose is pretty warm.

 

Sounds like air trapped in the system. it can take a while to get it all out.

 

any suggestions for thoroughly getting it out?

 

Sometimes it just takes running it, and topping up the system whenever it gets low in the radiator or reservoir.

 

Much appreciated Skrain. I won't worry about it over heating then. Glad I'll be getting on this in the morning as I only have a 8 mile round trip to work. I'm off around midnight so it'll be nice and cool outside on the drive home

 

Sometimes air can take a while to fully purge from the system. If you are only going that short of a distance, you should have no problem. it's not burying the needle in the hot, so it should be fine. It will run a touch hotter on just water then with coolant anyway.

 

Yup, sounds like air in the system.
How cool will it be? If you're running almost straight water, you could blow a freeze plug if it gets far enough below freezing. Funny thing is, that's how I got my truck! Guy popped a freeze plug (the one behind the timing chain) and thought he blew the head, because of the milky oil.

 

Today we have a high of 68 and a low of 37. Now you got me stressing. I hope the little coolant left in the system is enough to combat any issues I might have over night.

 

Not going below freezing you won't have ANY problem at all! Don't worry! it would have to be below 32 for several hours at minimum.

 

At those temps, you should be fine. You only have to worry if it goes below freezing for a long period of time.

 

Pretty easy to burp it. Keep the radiator cap off, top it off while the truck is running, and keep doing that for a couple minutes. Best to park with the truck nose high (jack it up if you want, or park on an incline). Keep your reservoir full while doing this.

Run until the bubbles are gone and you're full to the very top. Put the cap back on, drive it around and see how she does. Repeat if necessary. Only remove the cap when the truck cools for a bit, and use gloves and a cover towel to make sure you don't get sprayed with hot fluid.

 

well that's a relief. Left work early so I opened up the pet cock and unhooked the lower rad hose from the rad. I'll leave it to drain over night and get on it in the am. Thanks again!

 

You aint kidding! As soon as I parked it I popped the hood. I touched the cap and it was pretty warm, not hot. I cracked it and got no spray from the cap. loosened the pet cock and let it drain. Got another bucket under the lower hose and it slipped off easily. got a little shower, mainly my forearm. I am REAL familiar with what 120 degree water feels like and I'd have to say the water/coolant couldn't have been more than 140 degrees, probably a bit less.