[Cloakedbug]

If you open the system hot, and the system boils, it will fill with air.

Possible thats even the original problem? Testing the coolant change with cap off boiled it/integrated some air?

 

[Germaniac]

Edit: Found this: Saab Expansion Tank Cap - Calorstat 4395513 Looks different but the only one I could find currently.

The P/N for the cap is correct; probably the shop has just used a generic pic. For comparison:

Cap, Coolant tank Radiator 4395513 (1016617)

Cap, Coolant tank Radiator Saab 9-3 (-2003), 9-5 (-2010), 900 (1994-)

www.skandix.de

I'm not that fussy about "Original Saab parts" (cat turds incoming in 3...2...1... 😁 ) as long as the part is manufactured by a renown brand and delivered by a trustworthy shop (and backed up by PayPal or similar).
It's a part used by GM for a variety of models worldwide and only the Lord of Saabs knows where GM had sourced them.

 

[oeyvind]

Could it still be headgasket?

No way the head gasket. In that case the coolant reservoir would be "boiling" and the exhaust would be (without any doubt) quite white.

Refilling about two litre cooling liquid on my 900 NG/1997 every year. No-one can tell where the coolant liquid disappear, but so far it seems to have done no harm to the engine. Still average 0,8L/10km (0,34 G/M, 2,93 M/G)

 

[oceanviews]

Possible thats even the original problem? Testing the coolant change with cap off boiled it/integrated some air?

Thinking this could be it. Going to drain, refill bleed, and report.

 

[mio]

If anyone knows a source for a good cap or reservoir let me know

I found a cap in my inventory stash. If you're interested, send me your address (via the Start Conversation feature) and I will ship it to you.

 

[multisaabguy]

in none of the posts do you say whether your fan is working on low or high ,hum., and when you refill make sure you don't over fill ,go only to the max hot line or cold if it is because it does need room for expansion.

 

[BobSaabit]

FYI- the reason the dash gauge stays at 9:00 is that that is how it is designed. As long as the temp is in a non-dangerous range, the ECU will position it at 9:00.

 

[oceanviews]

Ok so a couple of notes:

I drained and refilled coolant. Went for long drive came back. This time coolant was violently boiling over/shooting coolant out. I did the combustion gas test again on reservoir. It passed. But with the car off I wouldn't expect for it to be able to detect gases/ or cold with thermostat closed? With car on coolant rises and contaminants the fluid failing the test. Im stumped. This whole cooling problem has been costly. Going to pressure test the loop tomorrow. Any other ideas on how to test head gasket?

 

[oceanviews]

in none of the posts do you say whether your fan is working on low or high ,hum., and when you refill make sure you don't over fill ,go only to the max hot line or cold if it is because it does need room for expansion.

My fan runs but only max.

 

[oceanviews]

My fan runs but only max. Never comes on unless ac is on or temp hits around 230f

 

[Germaniac]

Ok so a couple of notes:

I drained and refilled coolant. Went for long drive came back. This time coolant was violently boiling over/shooting coolant out. I did the combustion gas test again on reservoir. It passed. But with the car off I wouldn't expect for it to be able to detect gases/ or cold with thermostat closed? With car on coolant rises and contaminants the fluid failing the test. Im stumped. This whole cooling problem has been costly. Going to pressure test the loop tomorrow. Any other ideas on how to test head gasket?

The question is whether the thermostat is opening or not - for a test you have to remove it and hang the item in hot water to see if there is movement. Another hint is checking the hoses (with gloves!) whether they are hot or not.

Next time you are going for a test drive, watch for the exhaust or have someone watching it while you drive. White steam is one of the signs that the head gasket is most likely shot.

By now you may have to consider that the head is warped, depending on how long you were driving with the coolant boiling.

 

[jvanabra]

If the cap isn't holding the pressure and you're losing coolant, it's possible there are no exhaust gasses left in the system to detect. What you describe sounds like a blown head gasket. I would refill with water, follow EdT's advice on filling, then after letting it idle up to temperature immediately run the block test. Or, if it bubbles over just sitting there you pretty much have your answer. Don't drive it. Boost will exacerbate this issue.

 

[oceanviews]

If the cap isn't holding the pressure and you're losing coolant, it's possible there are no exhaust gasses left in the system to detect. What you describe sounds like a blown head gasket. I would refill with water, follow EdT's advice on filling, then after letting it idle up to temperature immediately run the block test. Or, if it bubbles over just sitting there you pretty much have your answer. Don't drive it. Boost will exacerbate this issue.

So I refilled and when the thermostat was supposed to open the level never dropped...This means thermostat isnt opening right? going to pull & test...if it wasnt a headgasket its sure heading that way...

 

[BobSaabit]

So I refilled and when the thermostat was supposed to open the level never dropped...This means thermostat isnt opening right? going to pull & test...if it wasnt a headgasket its sure heading that way...

We've had a lot of issues with aftermarket thermostats around here. Motorad is the original maker and those seem to work best. Bleeder hole positioned at 12 noon.

If you drive the car for about 10 minutes or even just let it warm up in the driveway, the thermostat should open and the upper radiator hose should get hot. Don't drive around for a half an hour and check that because it might be hot just from ambient heat in the engine compartment.

 

[oceanviews]

We've had a lot of issues with aftermarket thermostats around here. Motorad is the original maker and those seem to work best. Bleeder hole positioned at 12 noon.

If you drive the car for about 10 minutes or even just let it warm up in the driveway, the thermostat should open and the upper radiator hose should get hot. Don't drive around for a half an hour and check that because it might be hot just from ambient heat in the engine compartment.

I pulled the thermostat. Its a motorad 88c and opens in a boiling pot

 

[oceanviews]

I cannot get this thing to fail the combustion gas test...grrrr

 

[oceanviews]

This is the thermostat. Looks different from oem to me.

 

[EdT]

I had an aftermarket Motorad 88º thermostat. If anything, it let the car run cooler on the highway than it should. Assuming that it fully opened before the water boiled, it's unlikely to be your problem.

When did this issue start? Before you did all the work on the pump, thermostat, etc?

I am obviously far away, and I don't have good knowledge of the history of the issue or firsthand experience with the car.

What I would do, knowing what I do right now, is to get the coolant (or water, at this point) level right while sitting in the driveway. Like I said, fill the reservoir only partway and start the engine. Let idle. The level will rise some as things heat up, then drop like a sink with the plug pulled when the thermostat opens. Fill to about the seam on the tank, cap, let sit overnight. Check level in morning, adjust to the seam (half way).

Then start car and let idle. the hoses, e.g. upper rad hose, should go from squeezable to fairly tight as the engine warms up. When the thermostat opens up, the upper hose will quickly turn hot, and the rad will turn hot a little more slowly. It will take a while more idling for the fan to kick in. It should start well before the temp gauge leaves horizontal and heads upward.

If all this is good, take for a drive. The level is correct, and the system is pressurizing. There should be no reason for it to boil over.

If the above doesn't quire work out that way, we may have some ideas what to test then.

 

[EdT]

Note that after getting the level right, the cap must be on and tight. And the system should start to pressurize in fairly short order.

 

[oceanviews]

I had an aftermarket Motorad 88º thermostat. If anything, it let the car run cooler on the highway than it should. Assuming that it fully opened before the water boiled, it's unlikely to be your problem.

When did this issue start? Before you did all the work on the pump, thermostat, etc?

I am obviously far away, and I don't have good knowledge of the history of the issue or firsthand experience with the car.

What I would do, knowing what I do right now, is to get the coolant (or water, at this point) level right while sitting in the driveway. Like I said, fill the reservoir only partway and start the engine. Let idle. The level will rise some as things heat up, then drop like a sink with the plug pulled when the thermostat opens. Fill to about the seam on the tank, cap, let sit overnight. Check level in morning, adjust to the seam (half way).

Then start car and let idle. the hoses, e.g. upper rad hose, should go from squeezable to fairly tight as the engine warms up. When the thermostat opens up, the upper hose will quickly turn hot, and the rad will turn hot a little more slowly. It will take a while more idling for the fan to kick in. It should start well before the temp gauge leaves horizontal and heads upward.

If all this is good, take for a drive. The level is correct, and the system is pressurizing. There should be no reason for it to boil over.

If the above doesn't quire work out that way, we may have some ideas what to test then.

Testing the thermostat slower this time. Also does it matter it doesn't have the secondary valve oem does? Read this, "
If the secondary valve is incorrect it may not
close completely and coolant continues to flow through the bypass
port even though the primary valve is fully open. This will cause hot
coolant to return to the engine before it has been cooled. The engine
temperature will be hotter than required and may cause premature
failure of other components in the cooling system."

Around 190f thermostat is closed...

Clearly boiling thermostat is barely open if that.

Rolling boil over 220f...