FYI, cooling issues, watch out

Attached are images that explain the untimely demise of my Euro 308 motor (which will be rebuilt in the future). That is the water inlet totally clogged by 20+ years of crud. So, I would watch out for this, because I am sure that my motor is not unique.

The blockage caused two problems, 1) water temp read okay when it consistently was not, 2) water pump got air from vacuum (guessing) and burned up causing real trouble.
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If you're referring to the small tube it's an "outlet." It feeds coolant into the top of the coolant recirculation tank. I doubt this alone led to your engine failure. I suspect your radiator and every other part of your cooling system looks similar.

A "proper" (electronic) pH tester is a good thing to have/use if you don't change your coolant every two years. Can be used on lots of other things too.

By the way, did you have any idle speed problems with your car (too high, for example)?

 

Close. It is to insure air in the system finds it's way to the tank but otherwise a very correct statement.

 

Along with what Brian wrote, I'll add this (the reason I asked about idle speed):

"Old 09-20-2009, 02:16 PM
eulk328 eulk328 is online now
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As a basis to troubleshoot high or varying idle speed, make sure the little hose connecting to the top of the coolant expansion/recirculation tank is putting out a very healthy stream of coolant into the tank. The water outlet nipple at the other end of this small diameter hose gets badly plugged-up. This reduces or stops "fresh", hot coolant from recirculating in the tank which results in an overall lower temperature of the tank. Since the AAV is secured to the tank for the purpose of heat transfer it ends up getting less heat than it should and may not be able to completely close, or keep closed, the AAV via just the electrical heating element. This can be one cause of high or varying idle (a vacuum leak being the most likely other cause).

You can hear and see this stream of coolant quite well if you remove most of the coolant from the tank with a turkey baster. If there's not a strong stream shooting into the top half of the tank you've got a problem. Just make sure not to remove all the coolant in the tank for this test as you may introduce air into the system.

Incidentally, Euro 328's don't even have an electrical heating element in the AAV. All closure is due to coolant tank heat transferring to the AAV. Not sure about Euro QV's on this but I suspect it's the same.
Last edited by eulk328; 09-20-2009 at 03:05 PM. "

 

Whatever you like to think.

It is well known and the subject of Bosch tech info that the AAV only needs the heating element to fuction correctly. Many manufacturers do not even mount it in a location to get radiant heat. The radiant heat issue was even a test question in Bosch fuel injection schools I attended in the early 80's.

 

Is that the sign of not using distilled water or wrong type of coolant antifreeze?

 

It's not a question of what I think. The Bosch AAV on my Euro (Swiss market, actually) 328 has NO heating element. There is no electrical connector of any kind. No wires going to it. It's movement is dictated strictly by the heat transfer from the recirculation tank. So, in the case of electrically heated AAVs it seems they do not need to be on the tank, based on what you wrote. I can assure you they need to be mounted on the tank to work on the versions that have no heating element. Without a doubt, there are different part #'s based on this major distinction.

 

I think it's a sign of a once-every-decade coolant change program.

 

Probably not changed often enough. Glycol becomes ACIDIC with age.

 

From the Bosch technical instruction manual (1 987 722 159) it clearly indicates that engine/coolant heat works in CONJUNCTION with the heating element. On the next page (not shown) it goes on to state: "The installation location of the auxiliary-air device is selected such that it assumes the engine temperature. This guarantees that the auxiliary-air device only functions when the engine is cold."

This technical manual does NOT cover the un-heated (electrically) AAV.
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That is my guess, I have only had the car since 2007. No matter, I would watch out for this, because it was the only part of my coolant system that had an obvious problem before a brand new water pump quit. I leave the technical arguments to those who know more than I.

 

And probably sat without being run for a long time...

Rick

 

If I were going to look at a used car (Ferrari or other), with the thought of buying it, I would bring a pH tester to check the coolant. Very simple, very quick and may give an indication of how well the car was maintained (or not). If the coolant appears to be old, based on pH level, what else was neglected? Brake fluid perhaps? Something else? Of course there are plenty of other things to check too.

 

Basically, yes. Or perhaps once every thirty years coolant change.

Plus maybe some other stuff.

The sodium silicate in older antifreeze likes to start precipitating out over time and perhaps from pH issues. Plus, maybe a previous owner decided stop leak was good idea, and /or was also too cheap to buy distilled water.

Old fashioned green antifreeze should be changed every three years, newer HOAT antifreeze (Zerex G-05, others), is good for at least 5 years.

Looks like new radiator, and extreme coolant system flush, plus removal of anything that can possibly be removed for manual flush/cleaning, flush system again after driving a bunch, repeat flush a few times after driving a few hundred miles each time. Unless someone has come up with something that dissolved this crap without hurting motor parts.

You may be able to dissolve this by simply running pure distilled water for a short while.

I am sure someone at a radiator shop can give you better info than i can on if you can dissolve this.

Good luck.

Doug

 

Also, letting the coolant go that long doesn't seem to be great for the head gasket. I had an old BMW where the previous owner didn't change the coolant often, and when I had to replace the head gasket, it looked like the acidic coolant had corroded it (eventually leading to a break into a cylinder, which caused coolant to be burned).

 

Ah...yep, this would pretty much hit the nail on the head!

 

Agree. I have never seen a cooling system this plugged up, Ferrari or any other car. If it were mine, I'd tear the entire cooling system off the car and flush, clean and inspect every inch.

Spang

 

Unfortunately, you cannot stop there - the coolant system extends into the Block and Heads. The motor will need to be torn-down and rebuilt to get all of the gunk out of the coolant journals....and to fix the issues caused by the overheating.

 

Thats what I was thinking, running distilled water and flushing it and repeating that many times.
I have a small distiller at home and it is amazing how much stuff stays behind after distilling only a few gallons of water. Which means that when using non distilled water, changing the coolant/water mix a lot is actually a bad idea.

Helmut