Well by now I pretty well know my system, but wanted thoughts from the collective. Recent thermostat replacement, and I still see some "creep" in temps in spirited driving around town. Recently bled the radiator, checked the fans come on around the second mark, I guess 210 degrees +-. Noticed some coolant blow out of the expansion tank cap, so I'm thinking I'm just losing coolant there, a little at a time until the problem eventually swings the peg to the third mark, short of the final one at 250 degrees. Both fans are operating at this point, put them on common trigger wire as I have removed the AC. So, I am off for a new cap, at 1.1 BAR, correct?? I am also thinking at this point that the OEM radiator could well stand a R&R and rodding out, recalling Birdman's Canada trip where he found his clogged with &^* sludge after 40 years! That would also be a good opportunity to replace the side and bottom foam closures, as I have done the top with a better Armaflex material but the bottom one is pretty hard to position with the radiator in place.... TIA!!
well... Let me throw this out there. When I parked my car in 1995, it always ran at 185, no higher, ever, When i resurrected it in 2010, it sometimes ran hot, sometimes cooler, then hot again, no rhyme or reason, bled, multiple times, i had put new coolant in in 2010 during the resurrection. Verified my timing issues, still ran hotter than it should. When was the last time you changed your coolant, and how many times has it been changed in the past? Look at the attached pic. See that orange tinted white **** in the opening to the cross over pipe/ that stuff was on both sides. Hint: it was not calcium, the car NEVER had anything but distilled water and really old antifreeze in it. (I am the second owner, and knew the first owner) The additives in the antifreeze had depleted long ago, and allowed aluminum oxide to form in the outlets, from AL corrosion. It took some welding on the heads to bring the opening /mating gasket surface back to normal for good seal. I am now a FIRM believer in flush and coolant change every 5 years, MAX. Oh, BTW, with the corrosion plugs gone, the car runs 185, all the time, again. Doug Image Unavailable, Please Login Image Unavailable, Please Login
I would absolutely start with a new cap. Here's the suggested one: https://www.amazon.com/gp/product/B000B8N3GE/ And I'll "ditto" Doug - change the coolant every 3-5 yrs.
Top notch!! A VENTED one? None of my cars had a vented one, but I'm game....16PSI that's what I needed to confirm.. Raining today so I can take the old one with me. My car sits outside in an open garage although with our mild winter I did not totally drain it, but the T-stat change did rotate some of the coolant. A recent blown heater hose renewed some more!! I also like the Royal Purple ICE treatment which is formulated to fight electrolysis and normally drops temps noticeably, similar to Water Wetter. My intake was recently removed and resurfaced chasing some gasket leaks, so I'm hopeful if it was really scary the shop would have said something! It was one of those: "It was idling rough after $3,500 worth of work, so we resurfaced that and now it's really nice, that's $5,000."
What did they resurface, the intake where the carbs go? The intake where they mate to the heads? I am not sure they had to take the crossover off to remove the intake manifolds?? Did they charge you for new water cross over pipe gaskets? Doug
The correct expansion tank cap is the Stant 10230 (not the one linked above). Yours truly, The Expansion Cap Police https://www.ferrarichat.com/forum/threads/the-308-328-coolant-system-anatomy-of-the-expansion-tank-cap.576430
First off, its a minor difference. The long Expansion Tank Cap thread DID conclude though that the Stant 10230 is the most appropriate cap for our cars though. The 10230 has a spring-closed valve. The expansion tank therefore immediately begins to pressurize when the coolant heats and begins to expand. The air in the expansion tank is compressed and not released to the atmosphere. Air and coolant is vented of course should the coolant system pressure reach the caps rated pressure, which is 1.1 bar (16 psi) for the Stant 10230. As the system cools again the air just re-expands to its cool volume. The other "dangling valve" cap allows the air in the expansion tank to immediately vent as the coolant heats and expands. No air is compressed. The valve closes only when the coolant level touches the dangling valve. Again: this is only a minor issue which causes two minor problems. First, the valve may not close from the first drop of coolant, so the car may drip a tiny bit of coolant each time. Second, the cycle of purging and refilling introduces fresh oxygen into the expansion tank which then can dissolve in the coolant. This increases the oxidization (corrosion) and aluminum oxide precipitation in the cooling system.
A couple of points: The purpose of the radiator cap is to raise the boiling point. At 1 bar a 50/50 coolant mix will boil around 260F. It's not going to make anything run at a lower temperature and even if you are boiling off coolant you'd really have to get past the point where the expansion tank is empty before it would affect anything. If you are getting to the third mark while moving well, it's not the fans fault. They only come into play when you're stopped or near to it. Ideally the fans should be able to cycle on and off with the car at a standstill but that might be a bit of a tall order for a 308. If you're problem is with the fans it might help to put in a couple of relays to power them directly from the battery without going through all of the stock circuitry or you can upgrade to more modern and more efficient fans which can be installed without modifying or hacking anything up. I went down this same rabbit hole a year or two ago - you don't want to know what I ended up finding. Hopefully your issue will be something cheap and simple.
Well I am just starting to suspect compromised flow thru the old radiator, cheap enough to pull it down and see. I have changed to modern fans from Grainger, who match pretty well to the old Lucas and are dirt cheap in comparison... They do draw MUCH less power, being "modern"... Came out of an air conditioner or something... Just generic 12V DC fans....fit the brackets perfectly.
I had it in memory for years…..let me see......look at #3LCH7, 1/35 HP, 1/4" shaft. Maybe you do need a longer bolt in the support bracket. It will accept our stock blades, but it has a smooth shaft at end with flat side for a set screw mounting. I just said "F*%*& it and epoxyed the blades hub on the shaft, letting the glue fill the flat side, and jammed a steel "push nut" on the smooth shaft. Once cured up that seems to work. I did not think the effort of putting a set screw into the old fans would work. Maybe thru drill a cotter key or something if the glue solution does not thrill you, it worked fine though
OK NAPA did use a different maker than Stant. I ended up with a BALKAMP 703-1699 16PSI While the spring in the old cap felt strong, both upper and lower gaskets were heavily grooved by the mating surfaces of the tank. So far, so good..
