Cooling system problem 81 Zagato fuel injection (USA)

[BetaZagato]

Hi,
I'm having a problem with the cooling system of my '81 Zagato (USA version), 2L injection.
The symptoms are the following :
First of all, the water expansion tank is always empty and that's probably not good ;-)
When the engine is cold, I fill the reservoir up to the level as indicated.
As soon as I start, the tank runs empty.
While driving, the temperature stays ok, the ventilator switches on whenever necessary.
When I stop the engine, the expansion tank gets filled with boiling water that finaly gets out through the overflow pipe.
Which leaves the tank empty.

Now someone told me this is a clear indication of a blown cylinder head gasket ?
Others say its the radiator or the water pump ...
Jus before I bought the car in octobre last year, the engine was opened and the head gasket was replaced, the water pump was renewed, the distribution belt changed, ... so I have been told.
I don't have real evidence of it, but I know the guy who worked on it and kinda trust him.

Could it be that the gasket isn't fit properly ?
The car doesn't seem to loose oil, although there's always a very small spot on the floor.

Any ideas ?

Thanks, Michael.

[PAV]

If you are not having any leakage on the ground
It has to be going somewhere!

If you start your car and put your hand over the tail pipe blast ( a few inches back) a bit and let the exhaust hit your hand.

Does it appear green, yellow etc?,
How do you know that the system was filled and properly purged of air?

Have you done a compression check?
A leak down test?

Don't worry about trust, stuff happens all the time.

You could have a warped head, a blown gasket, or a very small leak in that gasket which is sucking in fluid, and pressurizing the system too.

It may be that you did not have the headbolts re-torqued after 500 miles, 1200 miles etc.

No reciepts? Get Reciepts for the work that was done, materials used.

If it was freshened up just before you got it, i"d think they would have shown you the proof or gave you a stack of reciepts.

Look for water/ coolent in oil.

If you remove the oil and a bunch of yellow stuff comes out... I think you may have your answer.

Find your rebuilder and ask him/her when they torqued the head - at what reading on the ODO.

Don't run it till you get it fixed else you will quickly destroy your bearings!!!!!

Best wishes,

Paul

[Jim Keller]

Sounds to me like you have a rusty over flow filler neck and or a rad cap that needs replaced. The way you say it is working is normal except the puking on the ground through the over flow, that says your cap is not holding pressure or the neck is rusty and letting the coolant expand past the cap seal and out the overflow tube, pop your cap, (when engine is cool ONLY), and inspect the neck, make sure it is clean and smooth so the rubber seal actually seals. Then if it is clean and smooth, get a new cap, 7 to 14 PSI if memory serves me right but double check that, don't rely on MY brain! ;D

[Will]

Yeah, you can also get small pressure leaks elsewhere that can do it, a hole in the reuptake tube or a broken reuptake tube so when the engine cools it draws in air and gives you a nice bubble in the coolant system, or you may just have a clogged up radiator, try this test:

IDLE the car for a half hour and shut it down. Still boiling over? Or is it only after you've been driving the snot out of it? The heat soak that gets dissipated into the colant is greater on an engine that's been driven hard and after you turn the motor off the water pump is no longer turning, the only thing circulating the water is convection. If you can't solve the problem and end up pulling the WP, make sure the hole above the waterpump impeller in the water pump gasket is open. And flushing the radiator real good or getting it rodded out is always a good plan IMO.

[BetaZagato]

I haven't been driving the snot out of it yet ... I've rarely been over 4000rpm (it's a shame, I admit).
Yesterday, I drove to a friend who lives about half an hour from my place, in my grandad style not going over 4000 rpm.
After I've stopped the car on his driveway, the water came out through the overflow pipe.
A little more than an hour later, we refilled the expansion tank and started the engine.
After only 5 minutes of running idle, we stopped the engine and watched the boiling water escaping through the overflow once more.
Indeed, the filler neck doesn't look too healthy, all dried up and rusty.

The guy I bought the car from has a spare radiator all cleaned up and ready to get it into my car.
But isn't this too big of an operation ? If it could only be the refiller cap being defective ?
And will it fit, its from an older Spider ?
Maybe I should take her for a compression test or check up for any leaks first ?

Another thing : the oil pressure indicator on the dash is nicely towards the middle when the eninge is cold.
But after a few miles of driving, it gets ackwardly close to the red zone on the left.
I've checked the oil level and it seems to be OK.

Thanks again for the ideas ...

[Jim Fierst]

From your last post i would have to conclude that you have a blown head gasket. Pressurizing the overflow tank to that degree indicates cylinder heat and pressure getting into the water jacket. If you do not heve the facilities to do a compression check take your Beta to a shop and have one done. My bet is on number 3 as the low cylinder.
I have a similiar situation with my oil pressure .. I added a mechanical gauge and it runs at 60 cold but 40 to 45 hot. Dash gauge acts accordingly.Idle gets down to nothing but no low light..
. In my turbo Fiat it is 80 cold 60 hot with a drop to 55 when the oil thermostat opens the line to the cooler.Idle is 20. It may be that the Beta oil pump just don't have the gear length/diameter. I can never remember which controls pressure and which controls flow volume.

[Will]

People are always tearing head gaskets off to find that's not the reason for their problems- and it's a royal PAIN to do a Zagato head, especially an FI one.

And there's always somebody who posts that you need to retorque your head gasket like, ever 500 miles. Well, you might have when the car was new, but unless you have a stash of NOS headgaskets, all the commercially available ones I've seen for sale are no-retorque type. And retorquing is only something you do to a NEW headgasket after it starts to settle in, it's not something you do at regular intervals. At least, it's not something *normal* folks do at regular intervals.

I would investigate the cooling system not holding pressure (bad cap or pressure leak), then a clogged radiator. If you DO suspect a blown head gasket, by all means don't start by ripping the entire head off- use the coolant additive exhaust detector stuff, that's what it's made for!
Or at least pressurize one hole at a time on the compression stroke (in gear, clutch out and not too much pressure) and see if your coolant bottle starts pissing.

And even if you now DO have a leaky head gasket, that could be as a RESULT of the engine overheating, which may well have been CAUSED by a problem in the cooling system.

As I reread your earlier post, you said your expansion bottle was dry- and you refilled it and started the car- I'm assuming you did a proper bleed and simply omitted that from what you wrote?? Because as you're probably aware, refilling the bottle won't get the air out of the system.

[Gregory Smith]

The '81 Zagato's expansion tank, where the "radiator cap" is, is the highest point in the late model cooling system and therefore self-bleeds. A couple of important items to check:

The small return hose in the end of the tank should have a brass orifice in it, and they often plug up. Make sure yours is free-flowing, or remove it altogether. If you don't get some flow from the small line in, the system won't won't bleed properly.

The cap should fit tightly, especially the inner cap's flange. If it doesn't, it won't hold pressure and will cause symptoms similar to what you're experiencing. An easy test is once the car is warmed up, opening the cap part way should result in pressure escaping and a boiling similar to what you describe at shutdown. If no pressure is heard to be escaping when you open it part way, then the cap isn't sealing.

I'd try a new cap even if your car passes the above test, since it also is meant to let air back in as the cooling system cools. Yours could also be plugged up in a manner not to allow this, which would contribute to your problem. If my memory serves it takes the "deep" cap.

Lastly, check your tank for cracks, they often have them at the seam. I fitted the former Budget Zagato with a tank from a late model volvo that is a perfect fit when mine was beginning to show age cracks. They have the same size fittings in almost the same places and provide a little more work room around it.

Hope this helps!

[Jim Fierst]

Just to follow up on that coolant bottle issue.. There was a new one on my 79 LBZ when iI got it and it split. I replaced it with a used one that also split . I also went the Vo;vo route . The Volvo unit seems to be more robust . I totally forgot about that possibility.
There happens to be one on Ebay if you need it.

[Will]

Greg;
When you say "self bleeds" do you mean you can just fill the whole system up via the expansion bottle, cap it, and drive off into the sunset? I spent so much energy fighting with the fan on mine that I don't remember for sure, but I thought I remembered having to run mine in several spurts with the heat on to get the air out. I might just be imagining that since my other Lancia (the Scorpion) was a total nighrtmare to bleed in stock trim.

[Gregory Smith]

Will: Yes, it's easy as pie. I suppose there's the occasional air pocket but they should work themselves out quickly without all the hassles of X1/9's or especially Fiat Spiders for that matter. I never had any issues with air bubbles as a Zagato owner.

The key is the small inlet hose, I remember discovering that the brass orifice on mine was nearly clogged solid with some sort of goo. I removed the orifice and cleaned it out, and always checked for flow after that. Without this flow in, the tank is just a pressure/fluid reservoir, and not a settling area for air bubbles as designed.

Why the orifice is there, I dunno, it seems it would work well without it, perhaps the flow is too much and causes foaming without the orifice? A proper coolant/antifreeze mix should keep that from happening. ???

The only time I had any cooling issues was when the expansion tank cap wasn't sealing and needed replacing. Otherwise it was always good, even in 110 weather in Ashland Oregon with the A/C running.

Dang now I sorta miss that car! :'(

[Will]

Maybe the orifice is there to keep from "short circuiting" the radiator by making an alternate colant path (through bottle) or to keep the bottle temperature down (just a trickle vs. big flow of piping hot coolant into plastic bottle). These coolant systems are trickier than they appear at first inspection, and often slight mods can have unintended consequences, as I have been painfully reminded on several occasions. You change one thing from stock and suddenly it's a whole new ballgame.
???
Yeah, that's the appropriate emoticon!!!!

[SubGothius]

Another frequent (and hard to identify!) place for the expansion tank to crack/rupture is at the center column fusing point, at least in the earlier (pre-FI) tanks, not sure if the smaller FI-spec tanks have this weakness. A deep dimple is moulded into the middle of the plastic shell on the top and bottom of the tank; the deep ends of those two dimples are supposed to be fused together inside the tank, creating a center reinforcing column that resists the bottle's desire to become spherical under pressure (or rupturing when it tries). In theory, at least. In practice, one dimple end or the other cracks off/apart, creating a leak in the center of the tank, where you'll never notice it nor see any obvious residue unless you're looking really closely.

Also, if you're talking about a brass sleeve inside the small hose nipple near the top of the expansion tank (where the small hose from the top of the radiator feeds into), my guess is that it simply reinforces that fragile plastic nipple, so even if it does crack or break, most/all of the overflow coolant is going thru the brass anyway and can't escape thru cracks in the plastic. That nipple also does seem to clog up with debris frequently, so it's a good idea to pull the hose off it and check/clean it out occasionally.

FWIW, I'd definitely go the Volvo 7-series junkyard retrofit route if I ever found my bottle breached in any way -- it's cheaper, stronger, and easier to find! 8)

[PAV]

THought to put in a small tad about my zagato the world famous Budget Zagato.

It appears that the head gasket was blown in my machine, that on top of one of the world's worst rebuilds. I put a lot of cash down to have someone do this in my hometown.
Well, it was taken apart by someone even more reputible in the Greater Seattle area and they took a number of Photos and are keeping all the bits and pieces.

There is a possibility of a blown head gasket (mine was #4) causing these problems.

Head was torqued etc.

Well the car always ran hot, then it started running hotter.

I shut it down and parked it.

Started it up and it appeared to have sucked the coolent out of the Volvo overflow. Let it run a bit and you'd swear that Old Faitful was feeding the bottle. Bubbles super hot, noises. So I shut her down.

The engine is being completely rebuilt and I will go over that in another chapter.

You really have to be careful about which rebuilder you take your machine to.

Their machine shop has to know what they are doing, and forget about skimping.

I had this machine completely stipped and gone through once before.

Now I took it to Seattle and had them take it completely apart.

What a mess.

Anyways, this may go down as the most expensive Beta in the past few years.

BR,

PAV