lostinthe202 Posted February 19, 2008 Share Posted February 19, 2008 '96 OBW 5spd 166k OK, so I've had some overheating issues that I've been chasing around. Very subtle and never flying up the gauge, just gradual ups with sudden downs upon sudden increase in RPM. There are lots of details, decisions, etc etc. that I won't bore you with. To make short work of the back story, I replaced the water pump and T-stat (both OEM) along with T-belt, seals, idlers, etc. When it came time to fill up the coolant, I went to undo the little bleeder screw thing on the passenger's side of the rad only to find it was busted. I was able to get it out (and back in sorta) but it def. didn't keep coolant from leaking through it after I was done refilling (with the heat on while on a slight incline) and something occurred to me. I'm pretty sure the water pump was failing as there was an awful squealing noise coming from the engine bay which was gone after reassembly and start up. All the pulley were free moving, quiet and had no play and while the water pump didn't make any noise when spun by hand, it did have a certain... lumpy quality when spun. Anyway, what occurred to me was whether it was possible for air to get sucked into the system through the broken bleeder screw? To step back to the symptoms for a second, the overheating would only begin to occur when I was pointed uphill, even a slight incline and the level would begin to rise even when the demands on the engine were not significantly increased if at all. I assumed that my system was marginal and that any increase in demand, however slight, was enough to cause the temp to rise. Furthermore, if it was a failing waterpump that wasn't spinning well, the sudden increase in rpm was getting the juices flowing so to speak and bringing the temp down in a hurry. BUT, if it were an air bubble, couldn't it have these same characteristics? Seems like it would since the system is supposed to be sealed up. So my subtle overheating problems could've been due to an air bubble trapped in the system and not a bad water pump. Any thoughts? I suppose I'll find out tomorrow on the way to work, but I'm interested in what you all have to say about it. This leads me to my next question which is how to go about this "burping" thing. Once I get another screw I'll go through the burping procedure again which from what I can tell simply involves being on a slight incline with the heat on adding coolant if the level drops and looking for air bubbles. Am I missing anything? Thanks! Will- Link to comment Share on other sites More sharing options...
msmithmmx Posted February 19, 2008 Share Posted February 19, 2008 Does it have the 2.2 or 2.5. I need to know before I read you the verdict. Link to comment Share on other sites More sharing options...
Skip Posted February 19, 2008 Share Posted February 19, 2008 Does it have the 2.2 or 2.5. I need to know before I read you the verdict. Sir, MSmith -- from cars 101 1996: First year for the 'real' Outback. Also first year for the 2.5L engine, which in '96 runs on premium fuel and is only available with an automatic transmssion. The manual uses the 2.2L engine and has the hill holder clutch. Will says "'96 OBW 5spd" Link to comment Share on other sites More sharing options...
nipper Posted February 19, 2008 Share Posted February 19, 2008 in a word, yes. Liquid molecules are much larger then gas (air). it is very possible to have a non liquid leak, but have an air leak. It also depends upon how the thread is broken. When it heats up, it expands and may seal up. When it cools down, it contracts. As the radiator cools down, it also causes a vacume (hence how the overflow tank works). Another thing to try is to start the car with the cooling system sealed. There is always a little bit of air in the cooling system. Spray a soapy solution on the bleed screw, and see if it bubbles as the car heats up and pressurizes the cooling system. YOu can always do a leak down test on the cooling system. Another thing is it can be a clogged radiator. How many miles on the car? nipper Link to comment Share on other sites More sharing options...
lostinthe202 Posted February 19, 2008 Author Share Posted February 19, 2008 Sorry msmith, it is a 2.2. Nipper, No need for the leak test on the bleed screw, I could see antifreeze pooling in the screw driver slots. I just wasn't sure if it could suck in enough air that way to be a problem. There are 166k on the car which I purchased with 120k. The guy I bought it from said his buddy was a dealer in PA that will give him cars that don't sell or some kinda weird story. The title had a bunch of transfers on it, but was clean. Supposedly It was a single owner car before me (at least according to carfax, so who really knows) but it didn't come with any service records. I probably would've passed, but it seemed like it was in really good shape especially for a car from the Pa snow belt. Virtually no rust, clean engine bay, clean fluids, and the price was right so I went for it. I just finished doing the T-belt and related goodies and I would say either it was well taken care of as all the parts seemed to be OEM stuff, or I got really lucky and all the original equipment held for 2.75 belt change intervals. But I lean towards the former as the oil pump screws looked like they already had loc-tite on them. So as for the rad, I know I can't really say without x-ray vision or a flow test. My drive to work this morning was trouble free with the gauge coming up to running temp about a 1/4 mile before it usually does (50 mph road) and staying right where it should be the whole drive (50 mi). I'll be keeping my eye on it and when I get a chance I'll go drive it through the mountains and see what it does. Thanks! Will- Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now