Air in cooling system

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So it's been over heating for 6 months. You have replaced almost every element of the cooling system, there are no coolant leaks, and it still over heats and you get air in the radiator. I'm still going with a leaking head gasket. I hope it's not, but with what has been posted that seems most likely.

Block tests are always conclusive, especially if you checked at the expansion tank. A better place to test would be to draw vapor from where the air is accumulating, the radiator, at the bleed cock. Cooling system pressure tests aren't conclusive regarding a head gasket either since the pressure is too low.

Now excuse me while make a friendly rag on you about using distilled water. I understand it is temporary, but distilled water doesn't have the correct thermal properties and will boil around hot spots (like in the heads around the exhaust valves) at a lower temperature than coolant. As I pointed out, in my car, and as other here have reported, with proper coolant, the difference between pissing coolant out the overflow and not pissing any out with the car idling or shut off hot can be changed by going from a 12 psi cap to a 16 psi cap. That change yields only an 8 degree F increase in boiling point of 50/50 coolant from 259 to 267F. But it is enough to stop the coolant at the hot spots in the engine from boiling once the car is shut off, or even at idle. On the other hand, distilled water with at 16 psi cap will boil at 242F, some 25 degrees lower. So it is not unreasonable that a QV may overheat at idle with distilled water it. This has been brought up before but you seem hell bend on ignoring it.

Doesn't look like a problem. Looks like a little corrosion. I notice that it is to the outside of the clamp. Probably the result of atmospheric moisture getting between the hose and the aluminum. You have already said there are no leaks. But what is this reddish deposit on the belt cover?

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The new pump will be more efficient. It may help keep the temperature down. But it won't address the accumulation of air in the radiator. (Or is that a red herring?)

 

Well ****. What I supposed to do with this cat? I was ready to go for tonight. you guys are no fun.

 

From https://www.thoughtco.com/signs-of-a-blown-head-gasket-4148136

I hope you new hose turns out to fix the problem, but.....

 

Looks like it is getting steam cleaned to me!

You're very fortunate that the repair is part of the future maintenance plans that you have in mind

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I recommend buying the tool. You may be able to make one, but you need the correct tool to re-torque the heads properly. It is a very tight fit even with the correct tool.

 

Buy the correct tool. It is not $200 but $95 from Ricambi America and as others have said the fit is pretty precise. If you are looking at a head gasket job the cost of the tool should be a frictional worry. If you really want it out of your life when done you should easily be able to get $50 for it in no time flat making your outlay less than $50. Even with all the fab tools at my disposal I'd buy the right tool for the job especially when head torque is a stake.

 

If the car is not over heating now I would drive it a number of times without bleeding the radiator after each drive. If you are truly getting air into the system eventually you should see coolant expelled from the over flow. If that is the case it would tend to confirm a head gasket problem. But that you are seeing the same pattern on all the pistons you looked at with the borescope seems odd in the sense that it would seem unusual for both head gaskets to be leaking for all (at least 1-5) cylinders in the same way.

 

There is a possibility depending on the year the intake manifold is leaking. The intake to head gasket on some years seal a water passageway..... just saying. .....

 

The Techron in the gasoline is doing its job?

 

Techron only does that in Techron's ads.

 

Correct!
That's why you need to use Techron concentrate plus

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Yike! I didn't mean to start an opinion war regarding fuel additives! Lets get back to Paul's problem!

 

No worries, you are correct
a good topic but for another thread

Remember to look for the plus to get the good stuff tho

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Can you expand on that - any clues as to which years/engines? Is that on both heads & beside which ports?

 

+1

 

Thanks for posting , and well done with the detective work too !

 

Can I put my two pennorth (cents!) worth on the subject.

I have a 1980 UK 308GTS. The water loss was excessive and basically out of control when I purchased the car, nothing would stabilize it for any length
of time. My findings may be of interest and are as follows:-

The small 'vent line' connection, from engine to header tank, did not continue, with a metal pipe, into the lower part of the header tank where the coolant
air/water mix could effectively de-aerate. The 'mix' was free to fall into the header tank where the inlet connection was soldered onto the top of the tank.

The result is, that when the engine is switched off, the pressure cap opens up the vacuum valve (as normal) as the coolant cools down. As the vent line
is not immersed in coolant the vent line draws 'AIR'! back down the vent line instead of coolant!

I fitted a small diameter polypropylene tube through the vent line connection and directed it into the far corner of the Header Tank, as far from the large
'make up line' to the water pump as possible.. ( In order to allow de-aeration of the air/coolant mix away from the suction of the make up line)

Instant result - just at the level Ferrari marked on the header tank.!!! - No more water loss, and, with a stable water level when cold.

Every time I bleed the radiator top tank all I get is coolant out of it. This is known as a result.

I hope this helps some of you to investigate if you have a "Friday afternoon" header tank where someone declined to do the job properly.

 

FWIW. from what I can observe, the expansion tank on my 328 does not have a tube going down into the tank at that fitting. I can see that easily with the engine running, the water stream shoot straight across the top of the tank. Are you saying that some expansion tanks had an "L" at the fitting that extended a tube down into the coolant and that the presence or absence of that "L" was a Ferrari factory error or error of the company producing the expansion tank as opposed to being the original design?