Heater Core Blown?

[gprocket]

I am trying to diagnose from a distance and need a little help. Thursday my son was driving the silver '91L and the radiator let loose. Fortunately the motor never overheated but there was a lot of antifreeze in the engine bay. I had a spare radiator so we were able get it back on the road in short order.

However that night my son took the car to the cottage and on the way steam started shooting out the cabin vents. He pulled over and filled the radiator with water and power washed the motor for good measure (I don't understand that logic but again I wasn't there). A few miles down the road the steam came back with a vengeance. This time he turned the HVAC off and the steam abated so he continued on. About a half hour later he said he started hearing a ticking noise. He turned the car off and restarted it and the ticking noise returned but the motor ran fine (no loss of power). After driving for a few minutes more he parked the car and shut the engine off. But this time the car would not restart. After about ten minutes he quit and left the car for the night. I am waiting for him to get back to it and see if it will start.

So my theory is that the steam out the vents means the heater core blew. And I further suspect that the moisture from the radiator steam bath and the subsequent power washing and the fact that it was raining hard all night all conspired to short out the ignition in some manner. The other possibilities include:


Blown head gasket. Not likely as I drove the car and watched the temp gage and it never went full scale nor did the over temp light come on. Nor did he report seeing any white smoke from the tailpipe.

Slipped timing belt resulting in ticking noise and no start. Not likely as he said there was no loss in power. He did say that it had a kind of diesel tone.

Does any of this make sense?

Thanks as always...

[Del]

You said there was plenty of coolant all over the engine bay after the radiator went. I suspect that some of that coolant got into the cabin vent system through the cabin system inlet at the base of the rhs of the windshield under the hood. Possibly because the seal on top of the false firewall was either not there or compromised in some way, or, the amount of coolant spraying everywhere just overwhelmed it. You can check this by pulling the a/c filter from that inlet and checking it for coolant.

If the heater core went, you would probably get running coolant down inside the cabin and inside the center console, as well as vapors in the vent system. I suspect the core is ok and the vapors are just coming from coolant in the inlet. The system will not retain pressure if the heater core is blown. Check that. If the system retains pressure, then you will just have to run the cabin air until the coolant has dissipated. Probably won't be fun. Keep the windows and sunroof open, and use rags over the vents to capture the vapors.

Also, if the engine wouldn't start, possibly there was coolant all over the ignition and in the distributor. That stuff will short out the ignition in a hurry, as if you had sprayed the engine bay with soapy water. The ignition system would have to cleaned throughly and wiped down with something like WD-40. Usually that helps preventing shorting.

Hopefully, the above is your only problem. Others may have more insight on this.

[Richard2]

Antifreeze all over the engine (including on the timing belt) and a jumped belt make sense. I power washed my Black 164S engine all the time for 10 years without any serious ill effects. Sometimes it would cough and sputter for a few miles but it always went away quickly. I tried the same thing after I got the silver 164B. It wouldn't start and ran really bad for a week until it finally dried out.

I doubt the ticking sound is related to washing the engine. If the belt is jumped 2 teeth, you may hear a ticking sound and not notice a loss in power. I'd print off the timing template and check the timing before doing anything else.

[gprocket]

Thanks guys. First of all, I would like to say that I prefer Del's hypothesis much more than Richard's! I will check with my son to see if there was any fluid on the floor. Regardless, the plan is to dry it all off and soak everything with WD40 as you suggest.

So Richard: I'm holding out hope that you are wrong. I will say that most of the AF went to the driver's side and I don't recall much on or around the belt. Good idea to print out the timing template. My question is this: If the Tbelt did slip but not enough to loose power (perceptively) would it be ok to drive it like that for say 30 miles? I assume that if I am still making power I haven't bent valves. That being the case I think I could drive it back to the shop. Of course this is all hypothetical as the car wasn't starting as of last night. I'll hopefully know more in a bit when my son calls in.

My inclination is to pick it up with the dolly and not chance it but I suppose if the valves aren't hitting and I can drive it, it sure would make things a lot easier.

Thanks again,

[gprocket]

Just got the update I was looking for: The rotor failed. My son said it was cracked and flopping around. So I am thinking that that would explain the no start of course but also possibly the ticking noise if it was randomly detonating. again, that's my hope anyway.

I also asked and he said that the steam did not have much of a sweet, anitfreeze smell to it so I'm thinking Del, you may be on to something. I'll know in a couple of hours...

[Alfisto Steve]

Quote:

Originally Posted by gprocket Thanks guys. First of all, I would like to say that I prefer Del's hypothesis much more than Richard's! I will check with my son to see if there was any fluid on the floor. Regardless, the plan is to dry it all off and soak everything with WD40 as you suggest. My inclination is to pick it up with the dolly and not chance it but I suppose if the valves aren't hitting and I can drive it, it sure would make things a lot easier. Thanks again,

[Richard2]

If the ticking goes away with replacement of the rotor, maybe it's safe to drive. you can easily use the template on the 2 cam gears to see if one jumped. it would only take a few minutes wherever the car is now. If it's still ticking, I wouldn't drive it at all.

[AlexGS]

Quote:

Originally Posted by gprocket Just got the update I was looking for: The rotor failed. My son said it was cracked and flopping around. So I am thinking that that would explain the no start of course but also possibly the ticking noise if it was randomly detonating. again, that's my hope anyway. I also asked and he said that the steam did not have much of a sweet, anitfreeze smell to it so I'm thinking Del, you may be on to something. I'll know in a couple of hours...

[gprocket]

Ok, a quick trip to the cottage and back and all day replacing my modem/router and I am back. Thanks for all the comments and suggestions.

In person I was able to quickly determine that the car was getting towed home. The heat core was in fact split and water was leaking out under the dash as well as from the engine compartment. With the rotor replaced the motor fired up without any problem.

So it looks like I get to learn how to replace a heater core. I am a little concerned that both the radiator and heat core failed in quick sucesession. It could be that they are old and needed to be replaced but is it also possible that a blown head gasket could allow leaking exhaust gasses to pressurize the cooling system? There was quite a display of steam vapor when the radiator went. ITOH the motor shows no sign of this - it runs fine with no loss in power and there is no water or white smoke coming from the tailpipe.

Thanks again.

[Alfisto Steve]

I would be suspect of coolant mixture ratio aka not 50/50 and low speed resistor failure or cooling fan circuit failure and non attention to temp gauge.

[MarkZ]

Steamy symptoms were exactly what happened a couple of years ago when I was taking my daughter back to college. Definitely the heater core. I had the car towed back to CT from NJ and mechanic was able to do the firewall shuffle and replace the core without further incident. The sudden depressurization probably did have a negative effect on the radiator, but this was not something that happened at that time - although the serpentine tensioner went at that time as well.

Mark

[AlexGS]

Quote:

Originally Posted by gprocket So it looks like I get to learn how to replace a heater core. I am a little concerned that both the radiator and heat core failed in quick sucesession. It could be that they are old and needed to be replaced but is it also possible that a blown head gasket could allow leaking exhaust gasses to pressurize the cooling system? There was quite a display of steam vapor when the radiator went. ITOH the motor shows no sign of this - it runs fine with no loss in power and there is no water or white smoke coming from the tailpipe.

[jontg428]

I replaced my heater core a year ago, not too bad of a job, there used to be a great link that had a step by step with photo's. it no longer pulls up so I guess the page is dead. Look at spending about 6 hours for the job if its your first time, like I said, its not too bad, and the heater cores are reasonably priced, I got mine from Jason at Alfissimo. Also its a good time to replace all those hoses as well, then you will be set!

[MrT]

That wouldn't be Bob's lexingtonma pages, would it?

http://www.lexingtonma.net/users/BobC/blower.php

It comes up for me tonight. And the 6 hrs isn't a bad estimate, from my experience. If you follow the directions and don't waste time agonizing over whether you see a better way.

I decided that one great advantage of 50-50 glycol mix over water is the decreased pressure as the coolant gets hot. Pure water stresses the system much more at temperature than does the glycol mix, simply because the vapor pressure of water at operating temperature is higher. Use 50-50 and don't stress the plastic end tanks. Or get special all-aluminum units. Jason (Alfissimo) has some of those. I have been sorely tempted.

Michael

[Alfisto Steve]

I would suggest you get a new blower motor for Saab 9000 from Welcome to eEuroparts.com for $63 to go with project.