900s cooling system question

I have a 1997 900s which I have just bought knowing it has some problems. I cant speak to the previous owner (deceased) but the clues are, there is a radiator in the trunk with a blown out plastic tank. The car has a new radiator in it, however, the water pump belt is off it... I started it for a second or two, and it runs fine, but as soon as it starts, smoke/vapor starts coming out of the remote coolant bottle. The cap was loose. This suggests to me that the previous owner popped the radiator and boiled the motor... how badly, I dont know. There is not alot of evidence of a major volcano under the hood.... but I would say the person boiled it, fitted a new radiator, then found the head gasket was blown...

So, my question, are the 2.3 motors quite resilliant to boiling? Or if one overheats, does it often warp/crack the head? Or is it normally just a case of putting in a new head gasket?

The car has about 197,000 km on it and it all looks pretty clean in the engine bay (the car doesn't look like a wreck)

The reason I ask, is just to get an indication if a head gasket should fix it, or if I should be looking for another head (or motor) because maybe once they overheat, they cant be easily rescued?

Can the motor be easily rescued is a question answered after you pull the head. You could give the shade tree mechanic lift and slip method a try with a 50% chance of success and risk doing the job again or you can pull the head, inspect the cylinder walls and have the head shaved and know if the head and block deck are OK. Either way you choose requires new oil, coolant, gaskets and head bolts, they stretch every time they are torqued and proper torque is essential on an alloy head. If it doesn't work the cheap way you buy more bolts, gaskets, oil and do what really should be done the first time.

Just in case mechanic slang isn't the same down under, a lift and slip is taking apart only what is necessary to free the head so as to be able to lift it high enough to pull the old gasket out and slide the new gasket in.

Thanks Digger, I wouldnt risk a slip job, I would want to check the head for damage. I dont know how bad it was boiled, or really if it was overheated at all... so I would like to do the job once and do it right.

The first thing I will do is a compression test and then have a look at the pistons and bores with the bore scope, then do a leak down test and look for air bubbles in the coolant and listen for air in the oil filler etc (a dead give away when you connect a compressor to a cylinder at TDC firing stroke and the dipstick pops out)

Some vehicles I have had, such as Subaru, if boiled... they are never right again, they always have problems after that, and other motor breeds have boiled bad and not even blown a head gasket.... I am trying to find out which category the Saab 2.3 is in.... hard to kill or fragile when it comes to overheating.

So, the head gasket bolts are torque to yield.... Does one change anything else as a matter of course when the head is off? Water pump? Timing chain?

Do you know of any good threads here on the 2.3 motor? Got any links? :thumbsup:

Strange, my last post didn't show up? I will say again... Nobody can be expected to read a forum post and say if a motor is any good, what I am asking is how susceptible 2.3 Saab motors/heads are to cracking or warping after a good overheat?

I am hoping to hear from other owners with 2.3's who might say "every overheat I have heard of cracked the head" or "Generally speaking, 2.3's dont crack/warp the head if overheated" .... so, if the answer is they usually wreck the head, I will start looking for one now.... if the consensus is that heads usually get damaged, I wont bother looking.

Though it may at times appear so, I am not a Saab expert, but I do know enough about GM to survive in the world of Saab. This Saab 2.3 looks like the GM Quad 4 and the early ones were infamous for blowing out head gaskets before they reached a hundred thousand Depending on driving and how hot the engine got before the leak was noticed makes all the difference in whether or not you will need a head. If the previous owner checked fluids on a regular bases and noticed the constant loss of coolant early on, a lift and slip will work most of the time. The old quad 4 heads did tend to warp and were as a matter of routine shaved when the engine got hot in city traffic and if quad 4 got hot on the expressway the head was almost always cracked.

As Saab has a history of not making all things the GM way, the alloy of the head may have been made with a recipe for stronger metal and you could be OK. With the end cap off the old radiator and not knowing the when or how, dynofluxing will tell you if you need to replace the head. As to replacing the water pump and timing chain, if the pump is the original might well change it out while it's easy to do. Timing chain if you want, chain tensioner is your best preventive maintenance while you have things apart.

An old thread I know, but just to add closure, I ended up selling the 900s as I thought the risk of it becoming a money pit was a bit too great.....and have now acquired a 2005 9-3 ARC with no issues.:)