We have a Subaru Outback. Three Mechanics have determined we have a valve going out or some engine problem that would mean taking the engine apart. Nobody is really definate. We have gone to the dealer they tryed replacing a fuel injector, one mechanic mentioned a valve. It runs and drives well but shakes and smells of exhausty fumes. This has gone on for a year. We would like to fix it, is there any one out there who has an clue? Does it need an engine or?
Has anyone run a compression check? If so, they should be able to give you the results. The exhaust fumes sounds like an exhaust leak, which has NOTHING to do with a valve going bad. Maybe a bad seal or corroded/broken pipe. The shakes could be a lot of other things that are far cheaper than a valve job, like bad coil, bad plugs, bad wires, etc. But, a compression check is the first thing to do to determine mechanical problems within each cylinder. If the readings show pressure 150 psi or better, and all readings are within 5-10%, then you are not having a valve or ring problem with this engine.
The bad valve would be diagnosed by a compression test. So if the cylinder in question has real low compression then its going to be expensive to repair.
An engine problem like that would be very uncommon for a Subaru, but anything is possible. The first thing I would do is get an empty spray bottle like Windex glass cleaner or something (BUT DON’T USE THE GLASS CLEANER!!!) With the water bottle, you should lightly spray aroung the ignition coil and plug wires. This will magnify a misfire if the coil is failing. Coils a common problem with that car, and would cause a fumy smell from the unburnt fuel. We have also seen this problem on some cars w/o the check engine light getting triggered. We always replace the wires with the new coil, because it frequently gets burned up from the misfire.