Cooling Suggestions- '85 Mondial

Water Wetter.

 

Something I did was to replace my rubber hoses that go from the engine to the radiator in front. They can fail internally or clog up, just like every other hose on a 26 year old car. I used silicone hoses that do not fail.

In addition, if your fuel hoses have never been changed in 25 years, Go ahead and keep some marshmallows in the car, as the fire is about to occur.

Good topic.

 

Your car runs way too hot. Mine never gets near that even in Hong Kong city driving. What is the condition of your radiator (mine is still original), water pump and especially the thermostat?
A small check would also be the existence or absence of the foam seals surrounding the radiator... small gain but still.

 

I would start with the thermostat and also check your expansion tank cap make sure it is holding pressure and one more consideration is you may have air in the system and it may need to be bleed.

 

ssrealty:

What does the engine water temperature gauge read when driving at 30-45 MPH in town at 90-100 degrees outdoor temperature? At 60-70 MPH highway?

Your motor water temperature should be 195 to 205 degree (maybe higher) when driving depending some on the vehicle speed and outdoor temperature.

A higher water temperature may be OK at higher speed or a hotter day. That is not generally a problem, but I understand it makes you worry about it.

Driving faster causes more heat in the motor, but more air moving through the radiator reduces the temperature. Just some of the variables/issues involved in heat transfer.

Your water temperature will also rise a few degrees when you first shut the motor off. That is normal. That is also why radiator hoses typically rupture, or clamps leak, after you shut off the motor. The temperature and pressure rise after shutting off the motor.

With electric temperature gauges, rather than capillary tube/mechanical gauges, people don't generally observe the temperature rise after they shut off the motor, because the electric gauge quits reading the motor temperature when you turn the key off.

You could also make sure you radiator is clean externally. Use a garden hose, or maybe a car wash pressure washer, to clean the radiator fins on the outside. Bugs and dirt reduce the efficiency of the radiator. Try to spray from the back side out first, then spray both ways. Use some soap, too.

The coolant pressure cap and antifreeze both raise the boiling point of your coolant, so the boiling point of you coolant is actually higher than 212F.

The oil temperature will be higher than the water temperature.

Good luck.

DRG

 

+ 1000 ............... "two bottles of Water Wetter" is what Eugenio advised as a "normal" coolant additive for my Rachel. When I look at the temp gauge as I drive her in a 90+ degree day here in So Cal (with the air on), an instant grin comes to my face.

Water Wetter won't fix a faulty cooling system, though it will probably help a bit (like a cast for a broken leg). But it absolutely helps in keeping a healthy system "cool".

Cheers, Hank

 

http://www.getahelmet.com/jeeps/tech/redline-chemist/

This is an article with good references to Red Line Water Wetter.

Also, some very good motor temperature related information.

"Surfactant" is the key word regarding motor coolants.

Just interesting information.

DRG

 

Anybody have some hands on experience with alleviating cooling problems? Instead of what "my mechanic" said.....

 

Since you changed and checked alot of the items that could cause an over heating problem, the only thing left would be to check for a clogged radiator.
This is usually the culprit with older cars from my experiences with my other cars. Let the car warm up, if there are no leaks from the water pump, you can try to feel the hose for water running through it but careful not to burn yourself.

See Birdman's write up:
http://www.birdmanferrari.com/service/coolant/coolant_troubleshoot.htm

Clogged radiator

It happened to me last year in the Mondial when deteriorating rubber hoses clogged the radiator with small rubber particles. I had mine re-cored for about $350 and now I have essentially a brand-new radiator. More often in older cars is a radiator which is clogged due to corrosion in the system and sometimes a radiator can be repaired by a rad shop by "rodding" it. (They take the top off the radiator by unsoldering it, then run a thin metal rod down each cooling tube to scrape out the gunk.) However, some shops will not rod an old radiator like this because they are afraid the metal is too thin and fragile. Especially when it says Ferrari on the top. I chose to re-core mine as a result. Drain the cooling system, pull the hose off the top of the radiator and look in there with a flashlight. You can see the top of the tubes and get a good idea what is going on. Re-coring means that they replace the cooling section in the middle of the radiator with brand new metal, and recycle the top and bottom of your exisiting radiator with all the mounting brackets, etc. It's much cheaper than buying an OEM radiator, and the newer cores are more efficient than older ones anyway because of a better design.

 

Here some temperature reference shots taken today, 86°F, at 50, 60 and 70mph and after 5 minutes at idle right after the 70mph/10mile drive, in a rather hot garage:
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How does your car do in 90f stuck in traffic ? Mine does the same as your car but in traffic it gets midway to just alil over, i.e. 53%. once traffic moves it goes down.

 

In really hot weather and stuck in a jam off the highway, the needles are about centered, then move back to slightly to the left of center while being stuck, in idle.
The cooling system is very capable of dealing with tropical conditions here, so engine temperatures have never been a concern.

 

Any foam on the sides?

The fans are controlled by a thermo-witch at the bottom of the rad, near the outlet; no connection to the thermostat, which is a that top of the engine water outlet.

Thermo-switch: At what temp are your fans starting? Mine start roughly at a 170°F water temp. If your fans start at a hotter temp, the fans may have a hard time getting things back under control.

Below a drawing of the instruments with the values of the unmarked marks... for reference also the green area Ferrari recommends as the normal range. and in red the no-go zone:

Thermostat: It could be stuck halve-open, in which case it the water would go out to the rad but only partially, the rest going back into the engine uncooled.

Not very scientific, but when you hold your hand behind the second fan... does it blow about as hard as the OEM one?

FIrst take your yours and make sure it works correctly. To me, that would be the first things to do, since you have already taken care of most of the other items.

Only after you have checked the thermostat, and made sure it opens completely at the right temp. Does it leak?

Not yet, only after you made sure the thermostat works correctly and the fans kick in at about 170°F.
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A temp gauge reading of 3/4 of the way is too high. Mine never came close to that even stuck in 90 degree traffic hovering around the mid point.
You should not take your car out in hot conditions, it will cause it to over heat and you will have bigger problems to worry about then.
Have your radiator looked at to see if its clogged, if so, get it re-cored.

CONSEQUENCES OF OVERHEATING

If the engine overheats, the first thing that will happen is a gasoline engine will start to detonate. The engine will ping and start to lose power under load as the combination of heat and pressure exceed the octane rating of the fuel. If the detonation problem persists, the hammer-like blows may damage the rings, pistons or rod bearings.

Overheating can also cause preignition. Hot spots develop inside the combustion chamber that become a source of ignition for the fuel. The erratic combustion can cause detonation as well as engine run-on in older vehicles with carburetors. Hot spots can also be very damaging and burn holes right through the top of pistons.

Another consequence of overheating may be a blown head gasket. Heat makes aluminum swell almost three times faster than cast iron. The resulting stress can distort the head and make it swell in areas that are hottest like those between exhaust valves in adjoining cylinders, and areas that have restricted coolant flow like the narrow area that separates the cylinders. The typical aluminum head swells most in the middle, which can crush the head gasket if the head gets hot enough. This will cause a loss of torque in the gasket allowing coolant and combustion leaks to occur when the head cools.

Overheating is also a common cause of OHC cam seizure and breakage.

Wait, there's more. If the coolant gets hot enough to boil, it may cause old hoses or an age-weakened radiator to burst under the increased pressure. Pistons may swell up and scuff or seize in their bores, causing serious engine damage. Exhaust valve stems may stick or scuff in their guides. This, in turn, may cause valves to hang open which can damage pistons, valves and other valvetrain components. And if coolant gets into the crankcase, you can kiss the bearings and bottom end of the engine goodbye.

Check for the following also if you have not:
* Lower Radiator Hose Collapsing -- A pinched hose (upper or lower) or a lower radiator hose that is collapsing and blocking the flow of coolant when the engine is running can cause engine overheating. The lower hose usually has a metal reinforcing wire inside that looks like a large spring. It s purpose is to prevent the hose from collapsing when the water pump is pulling water through the hose. If this wire is missing or has failed due to corrosion, the hose may collapse.

*Plugged or Dirty Radiator -- Dirt, dead bugs and debris can block air flow through the radiator and reduce its ability to dissipate heat. Internal corrosion and an accumulation of deposits can also block the flow of coolant. A good way to find internal clogs is to use an infrared thermometer to "scan" the surface of the radiator for cold spots. If clogged, the radiator should be removed for cleaning or replaced. Backflushing the cooling system and/or using chemical cleaners can remove rust and hard water scale, but may do little to open up a clogged radiator.

I found this to be helpful in troubleshooting over heating problems: http://www.tegger.com/hondafaq/overheating/index.html#traffictop

 

That seems correct.

So you are running at ±215°? That would be higher than mine, but still below the 230° Ferrari specifies as the max.

The only time my car ran hotter (a bit like yours) was when one fan failed. I would recommend installing a proper second fan. Since your second fan didn't seem to alleviate the hot running issue, it may just be too weak.

Half way is OK though. And it had only one fan.

So no worries about a blocked radiator.

That would be an indication of either too much coolant (and would stop after it spat out what was too much), or of running too hot... do you have to add coolant once a while?

I would check that though.

 

Absolutely...

 

The water pump should not have any drips, I would start with testing the water pump, get a new one or rebuild it, flush and clean radiator, and try again. Any leak around the water pump would suggest its starting to go bad. I dont think its a fan problem especially at cruising speeds. My gauge is below mid always when cruising.

 

I had a similar issue with my 348 some time ago. The problem was easily fixed by reducing the water/antifreeze mixture from 40/60 to 60/40. The Operating temperature dropped 30°C. Good luck.

 

I wish I had something more to add. Sounds like time to bite the bullet.

I'd asked my tech if I should flush out my cooling system and he said, "nah, if your radiator is original it will probably start leaking in the next two years and you'll have to replace it anyway"

It looks like your car runs just like most of ours, only a consistent 15 to 20 degrees hotter. If your hand held surface gauge confirms the temps it's not the sender or gauge. If it never got hotter going forward you could probably run like this but if you have one minor glitch in the system you have no margin of error, your car will truly overheat in short order. The radiators are old, at some point it becomes a maintenance item. Nothing lasts forever. Wouldn't hurt to renew the cooling system at this time as well. ie the thermostat and water pump if leaking or you feel its otherwise necessary.

I guess I do have something to add after all. The hose that goes from the center of the valley to the expansion tank. These are famous for becoming plugged and I thought I heard can cause hot spots or the car to run hotter? They are also less frequently replaced as they are hard to get to. The one on my car was the worst hose on my car and was partially plugged when I took the car apart for service. This will likely not be the only cause of running hot, ie not the solution, but one of those things that is worth looking at. With a flash light look under the plenum. Also, when you first start up (cold engine) you can have the expansion tank cap off and see if water is flowing into the expansion tank from that upper hose. Fastradio will definately know more about this than I do and may be able to add to it and confirm this issue or gently tell me I'm a fool

In my car this was the only hose that was visibly bad. Second picture is taken from where the oil filter should be, the line attaches to top side of expansion tank as shown in 3rd picture. You can also see the nipple in the second pic looking from either side of the throttle body.
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