Too Dam Hot 365GT4 2+2 with 400I engine

My 365 with 400i engine is just running to dam hot. It has never overheated but has touched 110C. This has happen when in high ambient temperature (89F to 98F) in slow to gird lock traffic. However, the fans come on and cannot keep up with the heat generated from the engine. Also, I have noted that even while driving the fans come on and do not turn off even at speed (40mph to 75mph) on the highway. Looking for some Ferrari Chart insight.

1. Radiator has been removed and boiled, cleaned out and tested. The shop assured me that the radiator had no silt, clogged tubes and is flowing at 100%. The shop as been fixing and repairing Ferrari radiators in NY for several of the independent Ferrari shops for 20 plus years. They said they would love to take my money and re-core the radiator but it would be stealing. There are some good shops still out there.

2. I have removed the thermostat and have tested the flow. I heated a large pot of water to 174.4F with the thermostat in it. Water flowed through with not much resistance. I then raise the temperature to 180F and the thermostat seemed to be fully open and water did flow with more ease. The question is should the water flow through the thermostat housing at 180F with little to no residence? How much resistance should there be? I poured hot water into the housing (When it was at 180F) and it filled up but drain fairly quickly but I would not describe it as free flow. Comments welcomed
3. Hoses seem aged but not old. They are all clear and firm not collapsed. I will be replacing all of them since everything is out and they maybe the most inexpensive parts on the car.
4. The fans come on at 86C on the dot but never seem to go off. If the do they come back on sooner and sooner to the point that they are running full time. I have included a picture of the fans. They are replacements that were on the car when purchased.
5. The car spent 28 years in LA California and I was told did not have an over heating problem.

6. The water pump looks find and the propeller is clean and shiny, no gunk whatsoever.

Any comments or thoughts would be welcomed. I expected the problem to be the radiator or the thermostat but it doe not seem the case.

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Small cracks in the head exhaust ports?

 

A crack between the valves is no big issue, but once the crack progresses toward the exhaust port (i.e downward in the following picture), the coolant gets quite hot.


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OK, if so, wouldn't that create so undo extra pressure in the coolant system? There does not seem to be any excess pressure. No coolant forced out through the expansion tank tube.

 

Hello, Frank......a couple of things.

First, AC on or off ?
Second, I have a spare T-stat that I purchased along with 2 cooling tubes a couple of years ago. I would be willing to send it to for you to "test" with if it will help, it is a used part but sold as good condition, so.......PM me. ( I also have a spare radiator but that would be $$ to ship )

On my '85 400i, if I am on secondary roads, AC off, 40 - 50 mph, ambient at low to mid 80's, then at a red light the fans will kick on when the needle is just before 90, with no further increase in temp. Green light and within 1/2 mile needle is going down and I can tell when the fans shut off.

Gary

 

On mine it was quite weird to tell the truth: at the beginning one of the ignition plug was harder to remove than the others. When cold, the exhaust fumes would look different on the left cylinder bank, and 110° when driving slowly (high speed was OK). Replaced the thermostat, placed new hoses, cleaned the radiator to no avail. After 2 months I ended up with high pressure in the system and decided to pull the motor apart. So yes high pressure in the end, but not at the beginning.

 

AC off, no need since my 365 GT4 is a spyder. I would love to get my hands on a test

 

Gary;

AC off, no need since my 365 GT4 is a spyder. Thank you for the generous offer, I would love to get my hands on a test thermostat. I can remove the front end of the car but do not know how to PM through this site. lol Free free to call or text my cell 631-664-5630.
I am repainting the radiator and cleaning / detailing the bottom of the engine and suspension over the long weekend. Then reinstalling the radiator and hoses to test again.

Frank

 

Frank, for future reference, to PM...
1. Upper right corner of this screen, click on your name or logo, should bring up a box of options, click on "Conversations".
2. That should open a second screen listing your current PM's (if any), then...
3. Same upper right corner of that screen should have a box/tab labeled " Start New Conversation", click on it.
4. Type in the " Nick Name" of who you want to start a private message with, and begin same as writing in a thread.

Gary

 

How are you verifying the temperature? The dash gauge or a laser gun?

 

Dash Gage and confirming with the fans not turning off after the turn on at 86C on dash gauge whether the vehicle is stationary or driving down the road even at speed.

 

If your fans go on at 86C, they will not go off until <75C, which is likely almost never. Ken

 

Even driving 60 mph in 75F?

 

Don't know if these work or not but it might be a first step to see if some combustion gas is getting into the coolant.

https://www.amazon.com/UView-560000-Combustion-Leak-Tester/dp/B000NPDL76

 

ChopTop, I changed my TStat for a lower shutoff but prior to that change with original TStat, the fans seldom went off once they come on. Exception low ambient temp, maybe below 50F.
Others?
Ken

 

I'm running a 82 degree C thermostat & the fans come on at idle & do not go off until I start moving again. When moving even at low speeds (60KPH) the fans go off. My temp gauge sits around 190 F most of the time. I only drive my car in days cooler than 35 degree C so do not drive it too much in summer as I'm in Central Australia. I have thought about replacing the radiator core with a more efficient one but have not got around to it yet.

 

Got to agree that when the fans do kick on they usually keep on for the rest of the trip, but 110C is a lot: that's close to the boiling point of the coolant. So safest approach for now would be to purchase AKJim quoted amazon tester and check for coolant contamination.

For my car I've bought an electric inline cooling pump, and also bought a replacement cooling fan (I'just plan on removing the yellow ASTI one and keep the Lucas). not installed yet, but that's what I am considering in order to keep temperature under when stuck in a traffic jam.

Last: if the ambient temperature is not too low, one may read the 365 owner manual and check for the recommend level of anti-freeze, as too much anti-freeze means less heat dissipation. Better to have less anti-freeze, more distilled water and water wetter.

 

"High Efficiency Radiator": I am sure there are modern aluminum radiators that are more efficient and one might find on to fit or have it custom made. People seem to prefer cross flow over traditional "thermo-siphon" top down flow, but not sure why. IMPORTANT - our radiators include the expansion tank as part of the top chamber. If the new radiator does not have a large tank on top a new tank will need to be fitted versus the little "vapor trap" we have originally.
Ken

 

Thanks to everyone that took the time to send in their thoughts. I am working through the problem one step at a time. Part time was kind enough to mail me a thermostat to test against the current thermostat, a great Ferrari Chart member.

I am having the expansion tank boiled out as I am writing this note. In the meantime, I have cleaned and straighten out all the fins and painted that radiator and thermostat to look like new. I am sure fresh paint will make the car run at least 10 degrees cooler, lol. I suspect that after resembling everything and filling with fresh fluid to a 50/50 mix that the problem will have been a cooling system that was not maintain correctly. I am confident that when everything is put back together and tested that the system will be running at peak manufacturing specs, whatever that might have been when the Ferrari left the factory. Will update everyone in the next couple of weeks as everything goes back in.

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I am getting back the boiled out expansion tank in the next day or two. The shop pointed out that they are media blasting the inside of the tank. This is nice and clean but is shinny bare metal (steel). Since the expansion tank at best only fills slightly with antifreeze the expose metal will start to rest very quickly.

Any recommendation for some kind of paint or coating that can be used to seal the expansion tank that will not peel when hot antifreeze siphons back into the tank over time and possibly get into the cooling system?

 

Just a couple of things to check.

Is the ignition timing advancing properly? if there's no advance, the engine will overheat quickly. This happens when the seals in the distributor post dry out and steam from the engine corrodes the fly-weight mechanism.

Are you seeing oil in the coolant? You might want to change the O-rings under the oil filter plate.

 

Ignition should be good, MSD discharged control installed before my ownership. Engine runs like a champ, acceleration very strong, no hesitation. Coolant is clean with no oil or any residue on the inside of the cap. Thanks

Frank

 

What else would leaky O-rings under the oil filter plate cause?

 

May sound like a foolish question but are the fans turning in the correct direction (pulling if mounted in the rear of the radiator and pushing if in the front); and do they move enough cfms of air to do the job?

 

Could well be timing issues then. Not so long ago one of us said this popular system had a few gremlins. Cannot find the thread though.