Overheating problem, help please...

redsvx94 · #1 04-15-2006, 10:04 PM

Hi eveyone,
I’m a newbie here but have had 94 SVX for several years, been lurking in this forum. I need a help to diagnose overheating problem.
I’ve been hearing some large whining (sounds like metal to metal contact) coming near where the AC compressor is located and thought that was the compressor, since I know it is locked up and I have been waiting for the replacement comming in. Yesterday after driving about 30 minutes, I saw the temp gauge shooting to red line. I limped back to home which is a mile away, keep driving and stopping for cooling. Today I ran the engine idling; the temp needle got to 3 o’clock position in about 12 min, and kept rising ¾ way to red line in total of about 20min. At that point I shut-off the engine and heard coolant boiling after shut-off.

The fan was working and the radiator hoses near the radiator filler cap were hot, so I assume it is not the thermostat. My oil seems to be in normal color, has no bubble on the dip stick. The coolant in the overflow tank and near radiator cap seems to be clear. So at least no large head gasket leak?

My question is as following
1. Would the water pump break down and caused this rather fast overheating? People seem to think that water pump would just leak when it goes bad?
2. Is there any way that I could judge whether the head gasket is blown at home? I am mechanically O.K., have installed tranny cooler myself and have basic tools. If the problem is only the water pump, that can be repaired (anyway I don’t know of sure whether the previous owner did timing belt at 60K or not and its getting to 100k). But if head gasket is blown, I don’t think my wife will let me keep the car…
3. In case, the head gaskets turns out to be O.K., could some one give me recommendation on an honest shop in Chicago land Area who could do water pump, timing belt and other required things like cam seal, at like several hundred bucks? Other wise I have to try them my self….
4. Any other thought on the problem would be greatly appreciated!

Thanks!

John

Trevor · #2 04-16-2006, 05:00 AM

Quote:

Originally Posted by redsvx94

Hi eveyone,
I’m a newbie here but have had 94 SVX for several years, been lurking in this forum. I need a help to diagnose overheating problem.
I’ve been hearing some large whining (sounds like metal to metal contact) coming near where the AC compressor is located and thought that was the compressor, since I know it is locked up and I have been waiting for the replacement comming in. --------------------------------

Thanks!

John

Are you saying that the AC compressor is seized up and its pulley is not rotating? Ckeck that the water pump is rotating and is also not seized up. If it is, don't run the car any more as you will further damage the timing belt back surface.

Listen for the noise using a piece of flexible tubing as a makeshift stethoscope and try to locate exactly what is making the noise.

Report back, so that those here can proceed with a logical diagnosis.

Meantime don't panic regarding the cost. May not be too bad.

Earthworm · #3 04-17-2006, 11:03 AM

If your waterpump is not working your radiator will not heat up due to non-circulation.

spinn360 · #4 04-17-2006, 12:42 PM

when my water pump siezed the radiator cracked from getting so hot. But your right rad shouldnt get hot but mine did. also some smoke, and squealing came from the timing belt on mine right before the water pump siezed.

redsvx94 · #5 04-18-2006, 04:36 PM

Thanks for the kind replies. I tried to test as Trevor suggested for a couple of days, but the car doesn't start. This however, is a different problem, I believe. When rotating the key, I just hear a click under hood and get no rotation. I have experienced this before occasionally, mainly when I tried to restart the car before it cools down completely. I used to wait a 10-15 min and it would start. I assume some kind of electrical contact or relay problem? But it never happened when the car was completely cool until now.
What I meant about the compressor locked up is that the compressor clutch doesn't engage when I hit auto button in the climate control. I think the compressor pulley is rotating, although I don't know whether the water pump is rotating. Should I try to solve the starting problem and move on to overheating problem, or is there any thing I could do now? Any idea about the starting problem ? By the way as I remember, the large whining was definitely coming from the general area of AC compressor though, I believe the water pump is under it.

SSSVX · #6 04-19-2006, 01:17 AM

Quote:

Originally Posted by redsvx94

Should I try to solve the starting problem and move on to overheating problem, or is there any thing I could do now? Any idea about the starting problem ? By the way as I remember, the large whining was definitely coming from the general area of AC compressor though, I believe the water pump is under it.

Of course, I think should solve the starting problem or how do you find out the overheating problem?

Was it every time you started the car and it got overheated? Starting problem could be as simple as a bad starter/starter solenoid or other possbilities. (do a search, lot of threads like this) Use your hands to move, try...you may find out what's stucked and made noise?

redsvx94 · #7 04-20-2006, 05:15 AM

I never had an overheating problem till recently, and the starting problem occurred infrequently, may be once a month or two? I did do search on starting problems, there are a lot of posts and it's kind of confusing....I just wondered whether the clicking sound is a sign someone is familiar with. I changed the starter about 10 month ago. I have to go on for a business trip from tomorrow till early May. Will try to fix the starting problem and report back after I come back.

svxcuseme · #8 04-20-2006, 06:26 AM

About the starting issue
My SVX is the 3rd Subaru I've owned to do this...Not restart when warm. Real pain in the ass. My solution has been to connect a starter button (thick gauge wire from positive lead of battery to one pole of starter button. 2nd pole of starter button to starter solenoid). I am trying to find a place to hide the button now. I could replace the starter relay, starter solenoid, or even the starter. But I don't feel like spending the time to diagnose. The starter button works every time and does'nt leave me stranded.

About the overheating
The Cooling system is composed of a few main components. Radiator, Water Pump, Thermostat, Cooling fans, Temperature sensor. Anyone of these failing components could lead to overheating.

An easy way to test your fans is to put the computer into Diagnostics Check mode by inserting the big blue wires into poles 1 and 2. Turn on the key, pop the hood, and make sure the fans kick on. If they work, check that they are kicking on when the car is hot (temp gauge around the midpoint on the instrument cluster). If they don't you have an electrical/sensor issue to diagnose.

Thermostats have been known to stick closed (really they still open but at much higher temps) once an overheating condition starts. My suggestion would be to replace the thermostat if the car has overheated more then once. A new 170º thermostat is around $8.

Radiators can build up sediment on the fins inside the radiator housing. This sediment build up prevents the radiator from being able to dissipate heat adequately and can even block the small radiator passages. It occurs over a period of years and can be very pronounced if you use tap water with your antifreeze and live in region with a lot of mineral content in your drinking water. No easy way to tell if this has happened, other than back flushing the radiator and watching for sediment to come out.

As far as the water pump. I know of no way to diagnose a bad one, other then visual inspections or process of elimination. Maybe others have tips on this. I've replaced mine when I had suspicions.

Good luck.

SVX-FF · #9 04-20-2006, 06:57 AM

John,

I had a major overheating problem and did all the usual test. The one thing that I did not know is that the second fan, the A/C fan, is what cools thing down when it get hot even with the A/C off. Make sure both fans are working when the temp starts to rise. If not check the A/C fuse in the fuse box by the battery. The fuse is right next to the FWD fuse slot. It is a 10 amp fuse.
It cost me $100.00 to find out.

Steve

redsvx94 · #10 07-02-2006, 10:46 PM

Hi All,
I have finally found time to get to work on my SVX. The starting problem seems to be fixed for the time being by starter bypass mod . I tentatively suspect either water pump or thermostat or head gasket leakage as possible cause of overheating. I hear horrible noises in the vicinity of AC compressor under which water pump reside and I can't determine whether it is coming from from compressor or under it even with pipe trick. I would like to remove the AC compressor belt and see whether noise stops or not. It seems belt is only rotating Idler pully and AC compressor? Would this be safe?

Thanks!

oab_au · #11 07-03-2006, 05:59 PM

Quote:

Originally Posted by redsvx94

Hi All,
I have finally found time to get to work on my SVX. The starting problem seems to be fixed for the time being by starter bypass mod . I tentatively suspect either water pump or thermostat or head gasket leakage as possible cause of overheating. I hear horrible noises in the vicinity of AC compressor under which water pump reside and I can't determine whether it is coming from from compressor or under it even with pipe trick. I would like to remove the AC compressor belt and see whether noise stops or not. It seems belt is only rotating Idler pully and AC compressor? Would this be safe?

Thanks!

Yes take the AC belt off, have a listen. If the noise is still there, it is probably the water pump, behind the timing cover.

Harvey.

Beav · #12 07-03-2006, 06:16 PM

Agreed, with Harvey. Please don't keep driving the car while it is making this noise! I personally know of several that have paid the price of a seized water pump. When the water pump needs replacement it's a good idea to replace the t-belt and hydraulic tensioner at the same time. If you let it go until the pump seizes chances are you'll be replacing those parts along with all of the pulleys, and at around $80 each they add up fast!

And then there's always the possibilty of toasting the head gaskets and radiator... They call me Dr. Buzzkill!

redsvx94 · #13 07-03-2006, 08:16 PM

Thanks for the replies. I have done that and the scratching noise I heard is gone. In stead, I hear a little bit of whining from PS, which probably was masked by the larger noise from Compressor. Now I hear slight thumping or hissing sound from engine, which may be from a vacuumed leak. At one point in past, I tried to locate vacuum leak since I was having a little bit of vibration when the tranny is in neutral position. I will deal with this more when I fix the overheating issue.

I really would like to figure out the source of overheating, I think I can change the water pump timing belt etc based info posted here, any way they are due. But I really want to rule out bused head gasket or head seal before I do those. I've replaced the thermostat and flushed the cooling system. I think I'm having a slight difficulty with removing air in the system as I refill it. Normally (for my RX-7) I first fill the coolant in the radiator, start the engine and when the engine reaches normal operation T, I see the coolant is sucked up as the thermostat opens up then continue to fill the coolant. Now I see the coolant starting to splash all over from radiator cap as temperature rises. I'm trying the method in shop manual, repeating adding coolant and running the engine till it reach normal T. Will report that whether I can avoid the overheating after that.

redsvx94 · #14 07-03-2006, 09:16 PM

Both radiator and reserve tank are full now but it still over heats. Should I wait until the system completely cools down, rather than cooling it for 30 minutes or so?
The top if radiator is hot the bottomed is just slightly warm.

The thermostat is new, both fan are working when the system reaches normal temp. Is it possible that the radiator is clogged? But it seems it drains fine.

Would water pump not pumping? I didn't see any sign of water leakage near the pump. Also When the temp gauge goes over the normal T, I see the temp gauge goes up if I step on accelerator a little bit. Is this sign of water pump pumping or head gasket leakage? I can see if there is air pocket and water doesn't circulate this may be possible...

Please let me know what I can do diagnose the problem.

Thanks

SVX-FF · #15 07-03-2006, 09:37 PM

If the engine temp rises during idle and then drops when you increase the engine rpms I would say it is time for a new water pump.

To check to see if you are circulating coolant, remove the rad cap with the engine cool. Start the engine and when she warms up you can see the coolant flow past the cap opening. You can also make a big mess doing this too. be careful.

Steve