phoenix1125

I recently bought a '98 Outback (2.5L DOHC) & am now faced with having to replace the HG. The car has about 100,000 miles on it & I'm hoping to drive it for another 100,000. I'm wondering whether it makes more sense to spend $1,000 on replacing the HG or $3,000 on replacing the engine with a rebuilt 2.2. I've read a lot of bad things about the 2.5's and am worried that if I replace the HG, I'm either going to blow another HG in the future or have other $1,000+ engine problems. Any words of wisdom in making this difficult decision? Thanks, Chris

I started a thread about a week ago regarding an overheating problem I've been having. The consensus seems to be that it's the head gasket, but the symptoms have changed a lot since my original post and I want to make sure that the problem couldn't be caused by something else before I go ahead and replace the HG. Here are the symptoms: '98 Outback, 2.5L DOHC. Problem first encountered after day of heavy driving in hilly environment: coolant seems to have overflowed from coolant tank & car overheated after coolant level dropped below critical level. After filling the radiator with water, we were able to drive ~30 miles home without incident. Took the car to our mechanic, the radiator passed the pressure test & there was no sign of oil in coolant. Since then, the problem has gotten worse: now, soon after the engine has warmed up, the radiator starts gushing coolant. Not only is it overflowing from the resevoir, but I have also detected a leak on the left side of the radiator which seems to start an inch or two below the bleeder plug. I have observed yellow particles in the coolant (approx. 1-3 mm in diameter) as well as a few larger black flakes (approx. 3-5 mm in diameter). Finally, I have seen large bubbles (1-2 cm) rising out of the coolant resevoir every 5-10 seconds. I know it's probably a head gasket problem, but here are my questions anyway: 1. Why does it seem to be leaking underneath the bleeder plug? Could this leak somehow be causing the problem? Alternatively, could this leak somehow be caused by a blown HG? 2. Could the problem be caused by a bad water pump, as in the following post? http://www.ultimatesubaru.org/forum/showthread.php?t=34301&highlight=particles+coolant 3. What could the yellow & black particles be caused by? 4. Could the problem be caused by either a bad thermostat (my mechanic put in a Stant instead of an OEM part), a bad radiator, or air in the radiator? 5. Finally, if it is the HG, could someone explain to me how such a leak could cause the radiator to force fluid out of the resevoir tank? I'm still a bit unclear on the mechanics of it all. Thanks in advance for your help, Chris

Well, I replaced the bleeder plug and it turns out that it was only a secondary problem: the car is still overheating. What seems to be happening is this: when the engine is under a heavy load, like when it is driving up steep hills, the radiator seems to be pushing fluid out of the resevoir tank (I saw evidence of this last night when I took it for a test drive). However, since replacing the bleeder plug, the radiator now sucks back coolant from the resevoir (just like it did the first time). Therefore, I suspect that my mechanic either broke the bleeder plug after pressure-testing the system or that it broke on its own shortly thereafter. My mechanic was suggesting that this behaviour could be caused by a clogged radiator; could this be the problem? If so, would you recommend buying an OEM radiator or are there any less-expensive (but still high-quality) aftermarket radiators you'd recommend? Are these symptoms still consistent with an HG leak? Specifically, I'm thinking about the fact that the radiator passed the pressure test and that it is sucking coolant from the resevoir tank. Anyway, I'm planning on buying a kit to test for hydrocarbons in the coolant; are there any other good tests you would recommend? Finally, if the symptoms are consistent with either a clogged radiator or an HG leak, which one seems to be the more likely culprit? Should I replace both parts or just start with one? Setright, thanks for your help: I found that post you wrote about changing the coolant & also a lot of other good advice of yours on the boards. Cheers, Chris

Thanks for the helpful responses; I'm new to USMB & really appreciate the warm welcome and good information. After reading a bunch of posts yesterday, I took a look at the radiator and found the bleeder plug -- and found that it was snapped at the neck and leaking fluid. This would explain the fluid loss and air pockets, but I don't understand how it could have passed the pressure test (& how my mechanic failed to notice it). Maybe it was the radiator cap at first, and then they accidentally snapped the bleeder plug when putting it back in? Still, I don't see how they could have snapped the plug without noticing it... As an aside, is $300 about right for "rodding" a radiator (or whatever it's called)? I just want to cross-check my mechanic's prices. Anyway, I bought a new bleeder plug and also an OEM thermostat & gasket (my mechanic installed a Stant), so this will be my first (hopefully minor) repair. With regard to burping the engine, this is what I've gathered: park the car with the front uphill, let the engine cool down (pref. overnight), open the radiator cap & bleeder plug, start the engine & blast the heater, keep adding 50/50 water/coolant until full, maybe bounce on the bumper a little, stop the engine when the thermostat opens & the coolant starts overflowing, then top off & replace radiator cap & bleeder plug. Does that sound about right? With regard to changing the thermostat, I'm planning on following the Haynes manual, but is there anything I should watch out for? From the posts, it sounds relatively straightforward... Gnuman, thank you very much for the generous offer; I may take you up on it if I can't figure it out how to do it on my own. Thanks again to all! ~Chris

My wife and I just made our first car purchase: a '98 Outback. We love the car, but recently started having trouble with it overheating. The problem started after we drove to the beach for an oyster barbeque: the roads were hilly and winding and I was driving faster than usual because we were running late. Anyway, when we arrived at the beach after driving for ~2 hours, we noticed that the engine was smelling a little. And when we left the beach some 8 hours later, the car quickly overheated after driving for about 15 minutes. At this point, the resevoir was full but not overflowing, and I noticed that it was thicker with coolant than usual. I also noticed steam rising from the area directly beneath the radiator cap. After the car cooled down, it took about one gallon of water to fill up the radiator and resevoir again. Once we did, we were able to drive home without overheating. I took the car to my mechanic, whom I believe to be good & trustworthy, but he doesn't specialize in Subarus. He replaced the thermostat and radiator cap and pressure-tested the system, but didn't find any leaks. He also checked the coolant for signs of oil and the oil for signs of coolant but didn't find any. And I haven't observed any bubbles in the coolant. I was hoping that it might just have been the radiator cap leaking, but the following weekend I took the car on a long drive in hot weather and, after 3-4 hours of normal functioning, it overheated again. It seems like it is functioning normally until it loses a certain amount of fluid, and then overheats. My mechanic thinks it might be that the radiator is partially clogged, but if that were true then I would expect the fluid to be overflowing from the resevoir. Is there any chance that the problem could be due to a loose or punctured resevoir hose? The hose feels somewhat loose/slippery where it meets the radiator, and there seems to be signs of radiator fluid/corrosion below that point (directly below the radiator cap; also where I observed the steam rising). Is there any way I could test to see if this is the problem? Are there any other ways the system might be leaking which wouldn't show up in a pressure test? Also, I'm looking for instructions regarding how to "burp" the system. I tried searching the archives but didn't find anything; if you have any advice to offer or know of any good links, I would be much obliged. Thanks in advance for your time and assistance.