August 2, 200520 yr Hey yall, Have a friend buying a 2000 forester with the Phase II SOHC 2.5...couple of questions 1. IS this as prone to HG failure as the phase I and if so where can they get the goop to help prevent it 2. Is this interference or non-interference Thanks yall Cory
August 2, 200520 yr Cory, ALL 2.5's are interference engines. As far as phase II Head gaskets, they are suspect to an external coolant leak. I would recommend ONLY the dealer/Subaru purchased sealer. You have an all Aluminum block and radiator. I wouldn't trust any other off the shelf sealer than what Subaru tested. They tried a few for over 2 yrs before releasing the one they did (My $.02). Most Phase II 2.5's will not develop this leak, but after the phase I problems, Subaru was under pressure to insure the phase II's didn't follow the same pattern. Also external leaks like this are remedied easily by a sealer. As far as being an interference engine, Most out there today are. Just be sure to do your maintainence at the recommended service intervals and you should be fine.
August 2, 200520 yr Yes, the Subaru 2.5L DOHC is an interference engine. That is an excellent question to ask, and I wish more car buyers asked it. Because an interference engine is a spectacularly stupid idea. In exchange for a very small increase in horsepower the owner is risking the complete destruction of the engine. It's not just the timing belt breaking that will destroy an interference engine. If the water pump seizes, if the tensioner gives way, if one of the idler pulley bearings craps out, if an oil leak (and there are plenty of oil leaks with a Suby engine) degrades the timing belt, you are soooooooo out of luck. Interference engine failure doesn't happen every day, but it does happen. And when it does, get out your check book.
August 2, 200520 yr There's no reasonable or obvious explaination why some engine designs are interference and some are not. There are some very high output engines that are not interference, and there are engines that can't get out of their own way that are interference. All Subaru 2.5 liter engines are interference, and so are the newer 2.2 engines. (I believe 99 and up).
August 2, 200520 yr Author interesting...well i guess we will check the timing belt....thanks for the info on the HG's...if i take it to a suby dealer is the additive free or do we have to pay?
August 2, 200520 yr interesting...well i guess we will check the timing belt....thanks for the info on the HG's...if i take it to a suby dealer is the additive free or do we have to pay? That additive is only $2.50 at the local dealer here.
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