Mondial Running HOT HOT - Expansion Tank Spilling Coolant

Any oil mixed in? I hope it isn't the head gasket...

 

Sticking thermostat, slipping water pump belt, bad water pump or blocked radiator are the most likely culprits.

 

Two questions; What cap did you buy? 1.1 bar? and is the expansion tank too full? I had climbing temps on the gauge near 240 degrees about a year ago. I changed out all the likely culprits but continued to have high temp readings. Before ordering a new gauge I cleaned the terminals/connections on the gauge and everything was good. It was dirty connections the entire time. The difference between your problem and mine is that I did not have spitting coolant. If your expansion tank is filled too high this can happen. It can also happen if the cap is too weak. Good luck.

Dan

 

Hmmm...if the oil temp rises with the water temp it's getting too hot. When mine was showing high temps on the water gauge it was not climbing as high on the oil. I would look into the system itself for a problem, i.e. thermostat, leak, radiator, etc.
I have a similar problem that started with the gauge reading high, so I bled, bled and bled some more. Then I cleaned the gauge contacts and it came back down closer to normal. Now I have some air in the system causing it to spit. I think it is just that, air. I have no unusual oil temps so I'm not that concerned.

Go back to the basics starting with a good flush, less coolant and more water, and bleed the system. You should have your radiator flow tested as well. It may not hurt to change the thermostat.

BTW...are your fans both kicking in at about 195 degress or less???? If not it could be the switch is bad.

You should also have good flow in the expansion tank. Check it with the cap off...you should see it returning at a healthy rate.

 

Going to a 1.1 bar cap will raise the cooling system pressure which in turn will raise the boilng point of the coolant. However, raising the pressure will put more stress on the components and can cause a failure in the system or expose some weakness in the system. Granted a 0.2 bar increase is not huge but if something is already marginal you might have more problems.

Have you driven the car with the heaters wide open? You should always do that after working on the system to make sure they blow heat. If at any point during the drive you lose heat from one/both of them you may still have an air pocket in there somewhere.

 

I would try a new thermostat first and see what happens. Cleaning the contacts is never bad but I think you've confirmed already that it really is overheating. As far as I'm concerned a 1.1bar cap is a band-aid and might do more harm than good. Plenty of cars out there that operate just fine with a 0.9 bar cap. Now if your 0.9 bar cap is weak then that's another story and a new 0.9 should take care of that.

 

... sounded pretty much the same as yours. Fine temps while driving but seemed to climb uncomfortably when slow or still. And forget about "stop and go".

I also did the bleeding and 1.1 bar cap exercise but it didn't work either.

What DID work was taking the radiator to a local shop who determined that the passages were about 90% blocked.

Per my radiator guy: The Mondial radiator has baffles in the top and bottom tanks that direct flow: From the inlet pipe at the top driver's side coolant flows downwards through the left third of the core, until it gets to the bottom tank. From there it flows across the tank until it hits the baffle that directs the coolant upwards through the middle third of the core. At the top tank again it flows across to the passenger side and down through the right third of the core and out the bottom pipe.

Here's was my major problem: The driver's side top third of the core was clogged, rendering the flow through the entire radiator very weak. It was clogged with bits of crud and rubber. The rubber was from the deteriorating inner lining of the coolant hoses.

I replaced all the coolant hoses and had the radiator cleaned and a leaky seam resoldered. The highest temp I see now is 195, no matter how I drive.

See: http://www.ferrarichat.com/forum/showthread.php?t=154645 (Thanks Birdman!)

Worked for me. Good luck.

 

Here's another from Birdman with part numbers and more info if you end up going the coolant hose route.

Nasty hose pic on page 2. Mine weren't that bad. Actually, most were OK, but had been previously replaced. Two were missed and were definitely on there way out though. Now they're ALL new.

The link: http://www.ferrarichat.com/forum/showthread.php?t=154843

Caveat: It took me about two weeks of evenings to get 'em all - even with a lift. But hey, I'm slower than most.

 

well, you've mentioned what happened to me a month ago,same thing no signs of water pump belt slipping,fans coming on and so forth,but when I took it in to the machanic and looked under the neck of the pump there is a tiny hole and it showed rust of where water was there and evporate because of the heat but not coming out that fast to drop water on the ground and I never saw this untill you really get in there and look,by lifting the car up and taking off the passenger wheel and inner cover,then you have access to the water pump,also grab the pulley and wiggle it,is there play if so the bearings are going which air can get in to the system,it nos'nt take much for these cars to get hot.........anyway this is what happened to me and this was the third pump in 4.5 years,alot of stress is on the neck and bearings so not buy a after market anything

 

what you think it's not the water pump,if bearings are on there way out or a seal is bad and air gets into the system that will make it run much hotter,I know this from experience,it happen to me,but go head and let us know how this works out for you,

 

What do you mean about your thermostat being stuck in the hole? You mean some corrosion? It sounds like you got it out. Did you test it for operation in the fridge/freezer and hot water/oven?

I had an overheating problem on my mid-engine, front-mounted radiator Lancia. I removed the insides of the thermostat (it's an external type thermostat) to see if the thermostat was causing the problem (it already seemed to check good for operation with cold and heat applied) and even without a thermostat the car was running much too hot. Replaced the 26 year old radiator with a new one and all was good.

 

Wanted to add........ get one of Verrell's bleed screws for the thermostat housing if you don't already have one.

 

Yeah, you'll fool with all the other stuff, and go through the same BS as the rest of us. Then, you'll take the rad out and have it rodded(don't just have it flushed, it has to be rodded), and make sure you fans are BOTH working right. Then it'll run at 190-195 all the time. I did it too, but I sure tried everything else first, just like you will.