New Radiator but still running hot

I just recored my radiator a few weeks ago. Everything seemed to be fine but yesterday on my way home from a show my temp started to rise. I got up to an indicated 225 degrees. Both of my fans are working and the t-stat and temp sensor were replaced maybe three years ago tops. I am leaning towards replacing the t-stat as the one in there now is not OEM. Anyone have any thoughts about this? I'm also wondering about the return line that runs behind the drivers side fuel tank. I had to splice a new section of hose to the old one and noticed that it was pretty deteriorated on the inside. Could this be causing a cooling issue?

 

Check your gauge, mine climbs to 225 I tap the gauge and it goes back to 190 instantly.



Wade

 

Try opening the bleed valve on top of the radiator once you get it hot. Probably some excess air in the system.

 

I'd definitely try bleeding the air out of the system before doing anything else. Birdman has an excellent tutorial on how to do this:

http://www.birdmanferrari.com/service/coolant/coolant_bleed.htm

 

i would be replacing the thermostate the 308 has a funny 2 stage system......... ......this is a habit i have every couple of weeks.....with engine cold remove rad cap remove bleed screw (put a rag under b/screw) top of radiator get rid of the air

 

redo under the hood where spare is to improve air flo ,the tub for the spare is jammed up against at least 40% of the back of the radiator i have been wondering what that would do for a while on the 308

 

You could do that "stove top thermostat feeler guage" test where you have the t-stat suspended by a feeler guage in a pan of water. The feeler guage handle is heavy so it goes on the outside, and one feeler suspends the t-stat in the pan. Once the water boils, the t-stat pops and drops completely in the pan. If it doesn't do this, you have a bad t-stat.

 

+1 for the bleed. I had my radiator rebuilt a couple weeks ago, drive it every day; and I'm still burping it when I get home each day.

 

Your fans may be working, but perhaps not at original spec. In other words, as the fans age they don't operate as originally - the bushes for example might be at the end of their life or the the bearings causing drag.

I just rebuilt my two (Lucas) radiator fans with new bushes and slightly heavier wiring and they run much, much better - probably pushing 2X the air they were before. These fans are the same as what's in a Pantera or later e-type jag.

 

I had a new T stat for another car, that went TU in less than 18 months.

It always ran a bit on the hot side, then it started getting hotter, suddenly.

I changed it and temp is normal now. Sometimes they are defective out of the box.

Ferrari T stats are no different than any other, and are made by someone else and put in a yellow box.

But, if your car is getting hotter at highway speed, you have either an air or water flow (water pump, T stat, hose clog) restriction, or possibly as others mentioned, air in the radiator, but my experience with air in the radiator is coolant puking out the over flow tank at idle or shut off.

Doug

 

I'll try bleeding it a few more times before I go the new t-stat route. I may replace the long coolant line as a winter project.

 

heh, mine does this too. I feel like a fighter pilot tapping the altimeter...

 

225 is too high, especially with a recored radiator. Something is up. Either the thing isn't bled or the thermostat is bad. More info: is this in traffic stop and go, or will it get this high while you are driving?

 

Barcheta, It sure did fine a couple of weeks ago for a long period of heat and high speed. It showed no signs of trouble then. Funny as it sounds, it couldn't hurt to try tapping on the guage next time.

 

I did the tap test while I was trying to figure out what the hell was going on. The gauge didn't move much if at all. Fernando fixed it a year or so ago. I was in stop and go in downtown Baltimore at the time. Mostly stop. It took a bit to heat up too. As soon as I got clear of the traffic it dropped in about 5 minutes to below 195 and stayed there. I suppose it it could be a bad gauge but I suspect it's probably either air or the T-stat as Birdman suggests. I'll let you guys know soon. Could be also as Cliff suggest that the fans even though they are working are not pushing enough air into the radiator. I've been contemplating putting in some hayden fans for a while now.... this might just be the signal to do that also.

 

* +1, I'd go with the OEM stat and bleed after every drive. Shouldn't run that hot, make sure radiator is sealed on the top and sides too.
When you bleed the radiator, be sure to have the heater levers in the hot position, air gets trapped in the heater core and must be removed.

 

Only one thing.
Maybe some air is trapped on the tubes going to the interior heating system. Open the levers of the heating radiator and after bleed again. See what says about that the Ferrari Owners Manual:

"NOTE:
When bleeding the system , it is necessary to keep the heating radiator valves open".

Only my 2 cents. -euro-

 

If the system is working properly you do not need Hayden fans

 

This is very interesting. I just finished doing my radiator yestarday and started the task of "Drive a little, bleed a little". I will open the heaters and do it some more!

Good call guys!