[donraye]

Hi all, Not sure if my problem is related to an "air pocket" or not?
A few days ago I was out on the backroads for a drive and one of the blades on my 16" puller fan broke and took out all the other blades with it. The 351 quickly overheated and by the time I limped into a service station the temp was just about pegging the guage at around250 degrees. There was water/steam being lost and by the time I got it cooled down some of the coolent had either boiled off or run into the overfloww tank.
Since then I of course replaced the fan with a new monster pulling over 3150 FPM and it works fine, BUT...
Here's the problem: Ever since that incident the cooling system has been doing some erratic and odd things and I do not know why or what to do to fix the situation. You need to know that I am NOT a mechanical whiz and this is a new type of problem for me and I have no experience in this area to date.
The engine is a 351 Windsor roller making 425 HP. It used to run at between 170 and 180 degrees (after fully warmed up) under all conditions from feeway speeds to cought in trafic at rush hour. Now suddenly it's running at 195-205 degrees in all conditions even on the freeway at 70 MPH and around 2500 rpm. Oddly it sometime runs at about 170-180 for the first 20 or 30 minutes (or longer if very cool ambient temps are present like cool mornings/evenings) but then it still eventually get up to the 200 degree range and just stays there. Sometimes if will actually cool down when you are stuck at a long light or at idle (when it should run hotter not cooler).
Any idea what is going on with this change of temps after the overheating incident? It sometimes seems to give erratic reading as well until it eventually get into the 200 degree area where it stays most of the time now.
Could it be that the overheating incident caused the thermostat to become faulty and no longer open where it used to? Could it be that the sending unit fo my water temp gauge is damaged form the incident and is no longer giving me a correct reading(telling me it is at 195-205 degrees when it is actually at 170-180 as it used to be)?
Or could it be this "air pocket" issue that you have talked about here in this thread?
Any suggestions on what I might do to find out what is going on with the system would be appreciated.
I was thinking to start by replacing the thermostat to see if that corrected the problem and if that did not work then to go on to replace the sending unit, etc. I have never heard about this issue with the air pocket so that's a new one for me to learn about. How would I check for or correct that issue and how does it occur?
Please remember you are talking to a newbie and a marginal mechanic at best, so make your suggestions or answers fit for an unsophistocated weekend warrior type mechanic with no experience in this particular area.
Don