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Discussion Starter · #1 ·
Alright, 3 raidator flushes, one new water pump, gallons and gallons of different coolant, new hoses, 2 thermostats and headaches later, my 9000 CS is stilllll running very very hott. The normal running temp is the needle right next to the red and if I try to drop down into 3rd to go by someone or anything other then babying it, it jump right up into the red and starts squirting coolant out of the top of the tank. No coolent in the oil or anything out the ordinary that way, just one Saab running very hott and one 16 year old running low on patience. Any last ideas before I bring it and shoot it in a field like a horse???
 

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I've been doing alot of reading lately for my recently acquired 9000 and I suggest your head gasket could be the culprit notwithstanding that you have no visible oil in the coolant or vice versa.You can have this checked of course. Apparently a sample of the coolant can be easily tested for the presence of hydrocarbons thus confirming or otherwise the presence of a blown head gasket
I stand to be corrected by our more knowledge able forum members
 

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Originally posted by colind:
[qb]Apparently a sample of the coolant can be easily tested for the presence of hydrocarbons thus confirming or otherwise the presence of a blown head gasket  
  I stand to be corrected by our more knowledge able forum members    [/qb][/b]
No correction necessary, this is correct . It's called a block test. With the engine warm and runnning, the tester, consisting of a glass tube with a special dye solution and vacuum bulb, is put in the top of the expansion tank. A vacuum is formed with the bulb, then if there are any combustion gasses in the coolant, the dye will change colour. Apparently it's very sensitive.

However, it won't detect a cracked head or a split in the gasket between two cylinders.

Going back to the original problem, have you tried checking the temp difference betweeen the top and bottom hoses to the rad?
 

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Discussion Starter · #5 ·
Its a '93 9000 CS nonturbo. The only tests I ran were I test the water temp and the thermostat allows water to come through as the correct time and the fan kicks on at the correct time. The funny thing to me is the fan doesn't kick on till the needle is almost the whole way up. I had to put a new head gasket in 2 summer ago cause it overheated and cooked it and the head was slighty warped but nothing that would need to be fixed.
 

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Experts correct if this is stupid but change turbo-model cooler to your saab. I think its bit bigger than nonturbo-model. My turbo runs with nonturbo cooler and everything is ok. Except on hotdays there might sometimes got litl high temperatures.
 

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If I'm correct, this car will have separate sensors for the temperature gauge and radiator fan. The coolant temperature sensor is mounted in the cylinder head. If it got damaged when the head overheated and is now reading the wrong temperature, then it might be reading very hot while the fan temperature switch (which knows what temperature the coolant really is) is still happy that everything is OK. Just a thought.

A colleague has just had the coolant temperature sensor replaced on his wife's 9000 (a '97) and tells me the part cost around £8 from teh dealer. I don't know whether the sensor for a '93 is the same price.
 

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If the water passing the fan thermostat was that hot would the fan not be running continually? or have I missed something - could it be as simple as requiring a new expansion tank cap - if working at atmospheric pressure would the water not boil sooner than if under pressure? Not sure just a thought.
Mike
 

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Originally posted by Mark E:
[qb]Doesn't this statement:

 QUOTE
... it jump right up into the red and starts squirting coolant out of the top of the tank.[/b]
Indicate that we're looking at something other than just a misleading temp sensor? [/qb][/b][/quote]Noticed that statement as well, which leads me to belive that there is a small crack or leak somewhere on the radiator hoses. My 9000 ruptured the upper hose last week after I noticed the temp gauge was running near the red on very hot days. I would suspect a crack or pinhole in a hose. The"squirting coolant" has to be coming from somewhere and the hose is the logical place.
Inspect the hoses carefully as a small leak can rupture into a blow out and drop all the antifreeze.
 

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Originally posted by Mark E:
[qb]Doesn't this statement:

 QUOTE
... it jump right up into the red and starts squirting coolant out of the top of the tank.[/b]
Indicate that we're looking at something other than just a misleading temp sensor? [/qb][/b][/quote]Err... yes. Didn't see that bit
 

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And it can't be a hose if it's squirting fluid out of the top of the tank.

Favourite for me is a head gasket failure. Need to check if there is any water on the dipstick as well. Then a compression test.
 

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Discussion Starter · #13 ·
My apololgy for not clarifing....the only time the coolant comes out is when its in the red running very very hott. A HUGE amount of pressure is put into the tank as I can see it expanded out almost to the point of simply blowing up. It seems to have its days as sometimes it will run very very hott and other days with the same air tempature, it will run much much cooler.
 

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You said you fried the engine 2 years ago - did the problem start then or is it more recent?

If recent, what was the last thing you changed or worked on before the overheating started?

Might help to narrow it down a bit.
 

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Discussion Starter · #15 ·
The fan belt broke 2 years ago and it got really super super hott, warped the head but didn't need to be fixed. Since then it always ran a little hott, like just above 1/2 way up but never anything that bad. It started to run real hott last summer but nothing that bad again. Starting this summer its been real hott. I put a new thermostat in thinking it would run a little cooler but didn't help. I then put a switch in the dash board to turn on the fan whenever I needed it. I would turn it on when i first started the car and the needle would still go next to the red. I just put in a new water pump and flushed the radiator 3 times in a matter of a week and took all the hoses out and made sure they were ok. Everything appeared fine and I got a another 180 degree thermostat and put that in. Still no change. Its been getting progressivly worse so on a 75 degree day I need to drive very easily and can't go on the interstate for more then 40-50 miles or it gets hott. I ran my a/c today for the first time in 2 summers to see what would happen and it hot hott after about 10 minutes and had to unplug it again. I had tests done and the thermostat is opening up at the correct time and the fan is kicking on at the right time/temp. but it just won't cool itself down. Really looking forward to winter to see what happen.....
 

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Originally posted by JOsh K:
[qb]warped the head but didn't need to be fixed.[/qb][/b]
I can't imagine warping the head and not having to fix it. What was the diagnosis of the failure at the time and what work was done to fix it? It's starting to sound as if the others are right about it possibly being a head gasket problem. Have you had a compression test done?
 

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Sister fried here 2.0T engine, head was warped and DI outer plastic covering coils on 2 and 3 melted (DI still works though!), head was warped. Put it back after skimming head but didnt check valves! Had no compression in two cylinders - warping the head had meant that the valve and seats though they looked perfect were no longer sealing so head off agian, lots of lapping paste and now everything OK.

So your warped head may mean valves are not sealing as they should hence overheating.

Alternatively when you changed the thermostats did you use genuine Saab ones (this is important) and did you fit it the right way round? OK may sound a stupid question but a mate had a similar problem with 900 and that was simply due to not fitting a Saab thermostat the right way round
 

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Valves not seating would mean very low compression thus less power and thus less heat.  IMOA  [/b]
I'm thinking lower compression (valves not sealing 100% more like 80% in one cylinder) hence slower burning of mixture hence burning latter in expansion stroke where more area in cylinder available for heat transfer hence hotter coolant. But it was just an off the top of my head suggestion.

Main thing is to get a compression test done
 
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