Hey guys, All summer long I drove my 85 308 QV without any antifreeze leaking from the overflow hose. I actually got a new radiator and new hoses in the spring along with new coolant so I was in good shape. I have not added coolant or water since the mechanic put in the new radiator. My car resides in a heated garage (around 50-55 degrees). When i drove it on Thanksgiving in 50+ degree temps, coolant leaked from my overflow hose when I got to my destination (20 minute drive). Today the weather was 45 degrees and again, coolant leaked from the overflow hose when i got to my destination. This is something I would expect in warmer weather and not colder weather. What do you guys think is going on? Coul I have a bad overflow tank cap or is there a problem with the thermostat? Thanks! Paul
The cap is probably the most common reason for the overflow problem. Make sure the cap is a 13lb cap. Mine says CST - T-13 on my 85' QV. Also make sure to purge the air from the system, VERY important.
I don't think there is any big problem at all. My car drips coolant everytime I drive it. I really think that air in the system sells more radiator caps thn anything else. Try bleeding the system really well and then let the coolant leak until it drops to the proper level in the holding tank. I bet the problem goes away. As for me it really doesn't bother me too much.
I was going to ask the same question! I have had my car a long time and it always drips a drop or two after a drive, but today when it was 28 degrees after my drive the collant got hot (not overheating) while I was trying to get my car lined up on my 4 post lift (a couple back and forths). I spit out maybe 2 or 3 ounces. Is that ok? The coolant level is fine. I recently topped it off when I had to tighten up a leaky hose clamp. Dan
My experience has been that gas* trapped in the system (from improper bleeding) expands quite a bit when it heats up and overflows the tank. I once tried to calculate how much the coolant should expand with no gas* in the system, based on the coeficient of expansion of ethylene glycol, but found it simpler to just follow the mfg. recommendation of having the cold coolant level 6cm (or whatever) below the cap. The thermal expansion of the ethylene glycol should bring the level up to somewhere just below the cap. If overflows, this is from either excessive temp (causing boiling, ie new gas* pockets that were not there previously) or expansion of gas* pockets left from improper bleeding. I suspect in some systems complete evacuation of gas* may be very difficult or impossible and one may just need to use a lower 'cold coolant level' to keep it from spitting and dripping when it heats up. *nitrogen, oxygen and vapor from ethylene glycol & water; not gasoline
cap. You should have a 1.1 bar cap - not a 0.9 bar like Ferrari says. Mine did the same thing in 1997, went to 1.1 bar and solved the problem. I have seen this with a couple others as well. The 1.1 fixed theirs too.
Being a scientist, I hate posting this, but... 0.9 bar = about 13 pounds 1.1 bar = about 16 pounds ...just in case you're talking to Bubba, not Alberto. -rick
this is a stupid question, but if you used the heater for the first time in a while because of the colder temps, you need to bleed the sytem at least twice. i have found that once it gets cool enough to have the heat on, i leave the heater valve in that position for the rest of winter. seems if you cycle it open and closed a lot, you get air in the system. granted it doesnt get "that" cold here in GA, but i think you get my point. *if you open the heater valve after its been closed off, you need to bleed the system.*
Anyone have a part number or cross reference for a generic 1.1 bar cap? Mine doesn't drip, but my cap is old and cruddy. Might as well replace it with a new one! Birdman
My independent mechanic advised me not to go with any cap over 14lbs. It is too much pressure for the cooling design of the 3X8 series cars. 14 lbs is sufficient. Dan
The 1.1 bar caps are now the Ferrari standard. Old .9 BAR caps are still available, but all suppersessions point to 1.1 http://www.ricambiamerica.com/product_info.php?products_id=198313
Tommy, Not trying to be a smarta**. What do you mean "obviously it isn't? Inquiring minds want to know. Dan
Can someone review the procedure for bleeding the rad in a 328 as it has been a while since I have done this? Also will I have to add coolant afterwards? It would seem that I shouldnt as long as the level in the tank is about 6 cm below the filler neck. Thanks, Dan
Actually, 14 lbs may be fine - it just needs to be above 0.9. My options at the Ferrari parts shop were 0.9 and 1.1 when mine did the same as Paul308. Someone at Rutland's told me that 1.1 was the proper cap so I bought it and put it on. The problem was instantly solved with no other repairs made. Based on that, the correct cap is somewhere between 0.9 and 1.1. As far as it being too much pressure and can say for sure it is not at least on my Jan 84 308. That 1.1 bar cap has 111 months, 40,000+ miles, about 30 good hard track days and 9 hot Alabama summers on it now. It hasn't given me a bit of a problem.
Put a new 1.1bar cap on it & bleed at the radiator & the top of the T'stat housing. You may have to do this several times before it settles down. Its not normal for the car to leak coolant & I don't think you'll find anything in the manual that suggests otherwise! If you feel the need then take the existing cap to any local garage - most of them have cap testers. The last Ferrari cap I had on my 328 only lasted about 4 ot 5 years & was failing at 0.8 bar (and tossing out large amounts of coolant) when I replaced it - the OEM caps don't last but they are also the only square ones I know of & therefore the only ones that look right IMO. I.
Search is your friend. I've posted the 308/328 radiator/coolant bleed procedure 3 or 4 times in both the old & new fchat TechQ&A.
Tommy, Now I understand where you were coming from. I had replaced my original cap with a Stant 16lb cap and shortly after had my water pump seal failed. My mechanic suggested not to use a cap greater than 14lbs which is in his opinion is comparable to the 1.1 bar. He changed mine to a porsche cap he had in stock and likes very much. Now my car is running like new again after a rebuilt water pump. Dan
Ferrari caps are garbage. Will not pass a pressure test after 1 year in service. Get a Stant Lever vent and forget it. If its looks offend you leave the OE cap in the trunk and put it on when the hood is open.
Don't have # handy but it is the standard old fashioned American size. Stant is the maker. They are the big dog in radiator caps. Lever Vent is their name for the style that has a pressure venting lever on the top.
I'm currently having the same problem with my Mondial. I bled the system this weekend then drove it for about 200 miles with no puddles or drips. I drove it to work this morning with the heater on and when I got to work there was a bunch of coolant pissing out all over the parking lot. I'm going to try the Stant cap per Rifledrivers suggestion today with a re bleed. I've had no problems all summer and am experiencing no overheating issues. If I understand correctly, don't get a cap over 14lbs. Is that gospel according to Rifledriver?
1.1 bar is 15.9541680264 psi. See my post above. I have never had a problem in 9 years. Now that may be because the cap is Ferrari quality so it is really only holds around 14 lbs OR it is because 15.9541680264 psi is just fine. Your options are buy the 1.1 from Rutlands or find the Stant that Rifledriver is suggesting. Based on my (and many others here) experience and Rifledriver's knowledge and expertise, either should be fine. Personally I would buy the Stant. It sounds like it is higher quality and less expensive. Next time mine fails that's what I am going to do.
Anywhere from 13-16 lbs. is OK. If the waterpump gave up at 16 lbs it was working its way close to the drain anyway.
