High tachometer reading

Just bought a 2003 Subaru Outback wagon with 105,000 miles on it and noticed that the tach shows 1500 rpm at idle even though the engine is barely ticking over. The tach seems to be several hundred over as it is driven. Any ideas?

Have you looked up the specification for idle speed? Is it out of warranty?

At 105k on the odometer, I think it is safe to assume that warranty coverage is over.
Normal idle speed for these cars is ~600-700 RPM (the OP did not state whether this was the 4-cylinder engine or the 6-cylinder engine).

An incorrect tach can be annoying, and if the car has a manual transmission, it will make it harder to select accurate shift points, but I would be far more concerned about another issue, namely the timing belt.

Since the car now has 105k on the odometer, I would advise the OP to have the timing belt replaced a.s.a.p., as a snapped timing belt will lead to ~$2k worth of engine damage–over and above the cost of the timing belt. The water pump should be replaced at the same time, along with the serpentine belt and all belt tensioners. (Note: This caution applies only to the 4-cylinder engine. The 6-cylinder model utilizes a timing chain, which does not require maintenance. Unfortunately, the OP left out the key information regarding which engine is in this car.)

The only major issue is that if your engine computer is also misreading the RPM’s it can lead to running problems and poor shifts by your auto transmission if equipped. However typically it would trip a Check Engine Light.

If it is just the gauge itself I would ignore it.

The car is an automatic and has the 4 cyl. It runs great and seems to shift fine. The tach idles at 1500 and then moves up as you drive so it is always reading higher than it should-3000+ when I think it should be lower as I’m not going over 60 mph. There is a lot of corrosion around the battery and battery holder at the bottom. You think it might be corroding a wire or connection that is affecting the tach? I am replacing the battery this morning so maybe I’ll see something. Is there any way that I can determine if the timing belt has been replaced? New gasket material showing anywhere? clean bolt heads? Thanks for info, so far.

The problem with the tachometer sounds like more of an internal fault with the unit itself.

As to the timing belt there is really no way of determining if it has been recently replaced short of tearing into it; and even then it can be near impossible to tell unless it was just done a few weeks before. Water pump and tensioners should also have been replaced.

If one doesn’t know for sure then it should always be assumed that it hasn’t been done at all. This is an issue that should be determined before buying the car; and that doesn’t mean taking someone’s word for it unless they have receipts to back it up.

Unfortunately, there is really no definitive way to tell if the timing belt has been changed–other than by getting hard copies of the car’s maintenance records. I assume that you did not get those records.

In the absence of maintenance records, you have to assume that none of the required maintenance has been done. I strongly suggest that you reference the 90k maintenance list contained in the booklet titled Subaru Warranty and Maintenance, and have everything on that list done a.s.a.p. All fluids and filters need to be changed, and the spark plugs need to be changed. Ignore the notation of “inspect transmisssion fluid” and be sure that the trans fluid is changed (not flushed).

While it is in for that 90k service, the timing belt, water pump, serpentine belt, and all belt tensioners should be changed also. You need to budget ~$800-$900 for all of this work, but unfortunately it cannot be considered optional unless you want to pay FAR more once mechanical problems surface as a result of lax maintenance.

Also–if the car does not have 4 closely-matched tires, that will also lead to AWD system repairs of an expensive nature. A set of new, matched tires might be a good idea if you see uneven wear from one tire to another. And, remember to rotate the tires every 5k or every 7.5k miles in order to prevent damage to the AWD mechanism.

Good luck!

Thanks for the replies. Bought the car from a KIA dealership for my girlfriend; she just has to have all wheel drive. I asked about previous maintenance history and whether there were any records. Of course they said there was nothing that came with it but they had checked the car out in their shop and everything was fine. The tires that came with it are all the same and the tread wear looks even. The thought of spending more money on the car immediately after buying it doesn’t make me too happy. I guess I should have done my homework!!!