[EdT]

You might want to try the same boiling test on the original thermostat. Maybe drop them both in.

The little valve helps take out any air pockets, and may help a bit of coolant around to the other side. As far as I recall, the Motorad I got from the parts store did have that little pin valve.

I replaced that with an OEM thermostat, in a Saab box from a Saab supplier. It was still Motorad, but not the same as the parts store Motorad in some details (which I forget, that was almost ten years ago). That thermostat worked just fine.

If going with a parts store, this looks right:
Part - MotoRad
265-192
THERMOSTAT-192 DEGREES W/ SEAL

 

[oceanviews]

You might want to try the same boiling test on the original thermostat. Maybe drop them both in.

The little valve helps take out any air pockets, and may help a bit of coolant around to the other side. As far as I recall, the Motorad I got from the parts store did have that little pin valve.

I replaced that with an OEM thermostat, in a Saab box from a Saab supplier. It was still Motorad, but not the same as the parts store Motorad in some details (which I forget, that was almost ten years ago). That thermostat worked just fine.

If going with a parts store, this looks right:
Part - MotoRad
265-192
THERMOSTAT-192 DEGREES W/ SEAL

I lost the old one somehow. I don't think it was even bad. Kicking myself now as I have to wait for one from esaab. Looking local in the meantime.

 

[multisaabguy]

you also might want to order the resistor necessary to fix your low speed fan ,since the high speed one is a high limit if the low can't cool it and your coolant is now that much hotter and at it's boiling point.

 

[oceanviews]

you also might want to order the resistor necessary to fix your low speed fan ,since the high speed one is a high limit if the low can't cool it and your coolant is now that much hotter and at it's boiling point.

Any good way to diagnose the fan? Someone said low speed only works when AC is on. Fans comes on frequently with AC on.

 

[Germaniac]

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

Looks different to me, too. Crosscheck with these:

Genuine Saab Thermostat Kit 89°C 30577561 | 30577561 | Neo Brothers

Buy Genuine Saab Thermostat Kit 89°C 30577561 at Affordable Price - 30577561 - View our range of [CATEGORY] for your Saab & Mini - Neo Brothers

www.neobrothers.co.uk

Genuine Thermostat for 1984-2009 Saab | Part# 30577561 | Over 30% Off All Genuine Saab Parts & Accessories | Saab Parts Counter

Find the right Thermostat for your 1984-2009 Saab with Saab Parts Counter. Part# 30577561. Not sure what you need? Use our VIN number search tool to find everything you need in one spot.

www.saabpartscounter.com

Really can't say if the different design does make the difference. Also, never heard of MotoRad before (just for fun - that's how we Germans spell motorcycle ), brands known to me are FebiBilstein, Calorstat, Valeo, Gates...

 

[oceanviews]

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.
View attachment 295259

Thank you for your kindness good sir you are a legend! People like you restore faith in humanity. However I just found my old oem cap. Going to swap the rubber ring and test.

 

[oceanviews]

Looks different to me, too. Crosscheck with these:

Genuine Saab Thermostat Kit 89°C 30577561 | 30577561 | Neo Brothers

Buy Genuine Saab Thermostat Kit 89°C 30577561 at Affordable Price - 30577561 - View our range of [CATEGORY] for your Saab & Mini - Neo Brothers

www.neobrothers.co.uk

Genuine Thermostat for 1984-2009 Saab | Part# 30577561 | Over 30% Off All Genuine Saab Parts & Accessories | Saab Parts Counter

Find the right Thermostat for your 1984-2009 Saab with Saab Parts Counter. Part# 30577561. Not sure what you need? Use our VIN number search tool to find everything you need in one spot.

www.saabpartscounter.com

Really can't say if the different design does make the difference. Also, never heard of MotoRad before (just for fun - that's how we Germans spell motorcycle ), brands known to me are FebiBilstein, Calorstat, Valeo, Gates...

From what ive been reading when the bypass valve is not present this allows hot coolant to be recycled back into the engine. This could increase coolant temperature thus boiling over. I believe wrong thermostat and faulty reservoir cap could be giving me the issues. Waiting for thermostat on Tuesday then will report. fingers crossed

Hopefully this is just a lesson on why you don't use junk parts and make sure they're also the correct part...

 

[jvanabra]

What do you mean when you say bypass valve? Are you talking about the jiggle pin?

 

[oceanviews]

What do you mean when you say bypass valve? Are you talking about the jiggle pin?

The secondary valve on the thermostat

 

[oceanviews]

Here is spark plug condition(piston 1-4 left/right) and what I could capture of the pistons. Only 5k on these plugs and they look shot to me. I don't have a compression gauge yet but Ill post those results soon along with coolant pressure test. But the pistons look moist from maybe oil? Also I never mentioned pretty confident oil is seeping a little from head-gasket.

 

[jvanabra]

Gotcha. Using a 2-way instead of a 3-way thermostat is unlikely to cause overheating and more likely to cause a lack of heat in the cabin. You should definitely use the correct thermostat, and I don't know specifically what you ended up with, but Motorad is the OE thermostat on at least the newer cars (2003+) and is a quality part. I think every car I own, which is 12 or 13 of them, has a Motorad thermostat. It routinely tops 110F here in the summer and even my '85 900 never overheats.

Edit: My XR4Ti has a Ford thermostat, because no aftermarket parts properly fits the housing.

"Overheating" happens at over 240F. You can monitor OBDII to be sure you're not getting that hot. Boiling over is a different problem, and indicative of either a system that can't hold pressure or a system with air in it. Air in the system expands dramatically more than water, and will force coolant out as it expands. A system that can't hold pressure will boil at a much lower temperature than a property sealed system, with the same results.

 

[oceanviews]

So I drained water out of the head via thermostat and the lower radiator hose. Refilled with cap off. Start car waited until it reached temp where thermostat should open and the water level doesn't drop. I squeeze top radiator hose and theres water in it already and cold. How is this possible? Thermostat is not stuck open.

 

[oceanviews]

Also I noticed my car started cutting in and out while testing...oh im out of gas. I limped it to the gas stationed filled up. But now the car still cutting in and out. Did I just burn up my fuel pump?

 

[jvanabra]

The system is self bleeding. There is no guarantee that air will get trapped in there during filling, it just might. It depends on how fast you fill and how well the thermostat is sealed and probably even on the specific angle of the car on the earth. In a perfect system filled fast, you may get a big burp. In a perfect system filled very slowly, you may get nothing.

The only thing you care about is that the upper radiator hose is stays cold for the first five minutes of running, and is warm/hot by about 20 minutes. Depending on the thermostat motor, it may get hot very gradually or very suddenly. Hopefully the former.

Once the upper radiator hose is hot, it's about as burped as it's gonna get. Sometimes a short drive will get a little more out, but once it's hot, water has traveled everywhere.

I doubt you burned out a fuel pump... or, if you did, it's because you routinely sit in traffic while you're very low on gas or something. That's something that happens gradually, not all at once.

Buy or rent a fuel pressure tested and determine for sure what's up with the fuel pump.

 

[oceanviews]

The system is self bleeding. There is no guarantee that air will get trapped in there during filling, it just might. It depends on how fast you fill and how well the thermostat is sealed and probably even on the specific angle of the car on the earth. In a perfect system filled fast, you may get a big burp. In a perfect system filled very slowly, you may get nothing.

The only thing you care about is that the upper radiator hose is stays cold for the first five minutes of running, and is warm/hot by about 20 minutes. Depending on the thermostat motor, it may get hot very gradually or very suddenly. Hopefully the former.

Once the upper radiator hose is hot, it's about as burped as it's gonna get. Sometimes a short drive will get a little more out, but once it's hot, water has traveled everywhere.

I doubt you burned out a fuel pump... or, if you did, it's because you routinely sit in traffic while you're very low on gas or something. That's something that happens gradually, not all at once.

Buy or rent a fuel pressure tested and determine for sure what's up with the fuel pump.

Maybe air in the line? It went completely dry. I got 16 gallons in the car somehow.

 

[jvanabra]

Nope. Not a thing... not for more than 2-5 seconds, anyway.

 

[EdT]

As the engine warms up, the coolant circulating in the engine gets hot and expands. This can push coolant, via the lower rad hose, up into the upper hose. And the coolant level in the reservoir tank comes up.....which is why you don't really want to fill it that much, it will overflow with the cap off.

As stated above, at some point the thermostat should open and the upper rad hose gets hot.In my experience, when refilling the cooling system, when the thermostat opens, any air in the system definitely gets purged, which is why the reservoir level drops.

If the upper rad hose is not getting hot, even when the engine is fully warmed up, you have a definite issue. I don't really know of any good way to test coolant flow, maybe someone else does. However, what you may have is a really bad thermostat, or the water pump isn't doing what it's supposed to do. That's why I suggested double-checking the belt routing there after replacement. The smooth side of the belt goes over the water pump pulley; that makes the pump rotate in the correct direction.

If the coolant isn't being circulated properly, yes, totally, it will boil over.

 

[oceanviews]

So the coolant situation seems to be solved. I put a OEM cap on and correct thermostat. It's not boiling over yet or losing pressure. However its one problem after another with this **** car. This is the sound its
making. I havent drove it but this is the idle: March 20, 2023. This happen when I was low on gas. Went to get gas and now its even worse. I don't have a fuel pressure gauge yet. Seems like fuel pressure is dropping and car wants to stall out. I put fuel cleaner in it a few hundred miles back and wonder if it clogged one of the injectors. No check engine light

 

[EdT]

Maybe some crap got sucked into the pump screen, or into the fuel filter?

 

[oceanviews]

Maybe some crap got sucked into the pump screen, or into the fuel filter?

Yeah probably. Im burnt out. I guess I'll start at pump and work my way up.