According to the “check engine” code, I have a bad knock sensor. (Which would explain the marginal gas mileage - but not the weird noises.)
Also: the transmission wouldn’t shift into first. The fluid’s fine, it might be something else with the engine. Oh yeah, the CV boot is ripped and I definitely have to get that replaced - and possibly a new front axle. Oh joy.
I never thought I’d have to say this again, but if you can throw some money my way, it would be much appreciated. Please hit the Paypal or Amazon buttons if you have anything to spare.
The most important advice I can give you is to make friends with someone who knows something about cars, then find through word of mouth a very good honest mechanic.
As far as your knock sensor goes, it sounds like your sensor is erroneously telling your engine computer that the ignition timing needs to be adjusted to compensate for the perceived knock. This will reduce your gas mileage, make your car run sluggish and decrease the acceleration when you really need it. That’s important to change soon.
As far as the CV boots go, I’ve been running on torn/missing CV boots on my old Camry for > 18 months now. There isn’t much difference in the price of changing the boots/joints w/ and w/o the axel included, so my mechanic suggested that I just let the thing wear out totally before doing the repair. Why pay before you need to in case something else kills the car? He said I’ll know it’s time to make the repair when the click-click metallic cracking noises become unbearable to hear. For my Camry there is no safety concern with allowing the part to just fail.
All total, my mechanic has been working on my family’s cars for several years now. He repaired an $11K dealership diagnosed “blown engine” for $350, and is able to consistently make my repairs using quality after market parts for about 60% of the price quoted through the dealership. I also have confidence that a needed repair is also actually needed at this time and not something that was padded into the estimate.
Also: Buy a repair book for your car. They are helpful with diagnostics and some repairs are actually easy to do on your own if you have an even modest tool collection. Screwdrivers, wrenches, pliers…
Hope my small $$ contribution helps you get back on the road.
Good luck!
Excellent advice from 1wasabi.
I’m curious about the transmission not shifting into first. Do you mean you can’t get into gear at all, or it won’t downshift from a higher gear?
Just a guess: I believe that auto trans are partially controlled by engine vacuum (step on the gas, vacuum increases, trans downshifts). So an old leaking vacuum tube (from engine intake to transmission control) might be at fault. Failed tubing on my old Camry (coolant, ac, heater) has been a continuing problem. Those are easy to fix.
Poke around the engine, rattling various tubes and connections. Maybe you can spot the break or leak.
When I started the car to take it to the mechanic’s, it went into reverse but then it wouldn’t go into drive. (It’s an automatic.) So after I stopped sobbing, I moved it through all the other gears, and then it worked.
The guy in the Auto Zone who read my “check engine” code said the bad knock sensor can actually have a chain reaction that would send the transmission an inaccurate signal. Hard to say, since he was trying to sell me a new knock sensor.
Susie,
What is the make, model and year of your car? I see a lot of diagnostic info about knock sensors on google. Perhaps your sensor is not too hard to replace.
BTW it is important to fix the knock sensor to protect the engine. Don’t let this go. Perhaps the transmission thing will go away when you fix the sensor but I tend to think it’s a different problem.
It’s a ‘98 Subaru Forester L. Yes, I will take care of the sensor ASAP.
You have lousy luck with cars, have you thought scooter?
I had the front left axle of my car break and fall off recently and it was very scary.
98 Subaru Forester L. That’s the same car I have. If the check engine
light (knock sensor) is intermittent (mine is), it might be the gas. Mine started exactly when they started adding more ethanol to the gas. It only comes one after I have just filled up, stopped the engine for a short time and then started it agian. If it sits for 30min or more…no light.
Oh and I got one of those plug in things to read the codes. Pretty nifty.
And yes get a good mechanic. Dealerships suck.
Chris
Susie - Here’s one link….
How do you change a knock sensor on a 1999 Subaru Legacy Outback?
Answer
ALL Subaru knock sensors are: 1) in the same place 2) look the same The knock sensor is always found mounted to the engine block (10mm head on bolt) under the intake manifold in about the middle of the engine. Either being a Bosch unit, or a copy made under licence, they all appear to be the same: http://rb-k.bosch.de/en/start/sensorik/kopfsensor.html Being the one with the moulded-in leads. Locate the wiring in the vacinity of the throttle body and follow it down to the knock sensor. Changing one needs about $100 worth of tools, small hands, and LOTS of patience. They are expensive, be warned, before you buy check the thing with a volt-ohm meter, typical resistence is 300-500 ohms.
http://wiki.answers.com/Q/How_do_you_change_a_knock_sensor_on_a_1999_Subaru_Legacy_Outback
From what I understand, there’s very little labor involved - so it’s cheap to get it done.
By all means have the work done by a good mechanic. It does sound simple.
BTW, were you aware of this safety recall on the Forester:
JD
MAR 03, 1999 | Recall ID# 57117
Recall Reason SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:MASTER CYLINDER
Recall Date MAR 03, 1999
Model Affected FORESTER
Potential Units Affected 221987
Recall Summary
VEHICLE DESCRIPTION: PASSENGER AND SPORT UTILITY VEHICLES EQUIPPED WITH ANTI-LOCK BRAKING SYSTEM (ABS). (THE 1999 2.2 LITER LEGACY VEHICLES ARE EXCLUDED). IN EXTREMELY COLD WEATHER, THE BRAKE PEDAL GOES TO THE FLOOR AND THE VEHICLE STOPPING DISTANCE IS INCREASED.
http://www.internetautoguide.com/auto-recalls/99-int/1998/subaru/forester/l-sport-utility/936/index.html
Consequence
THIS CONDITION CAUSES THE VEHICLE STOPPING DISTANCE TO BE INCREASED, POSSIBLY RESULTING IN A CRASH.
Remedy
DEALERS WILL REPLACE THE BRAKE MASTER CYLINDER.