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Xist 04-29-2013 02:20 PM

Faulty knock sensor
Edit: Hopefully, this is finally resolved. My check engine light came on, giving me a Faulty Knock sensor code. My mechanic wanted way too much to fix it. Another said that I just needed an engine treatment, my knock sensor was fine, but my engine was knocking. I had them replace my timing belt and ten days later the light was back, but my car was running rough. They wanted $266.80 for a "Valve clearance adjustment" and $124.23 to replace my spark plugs and wires. I did the spark plugs and wires myself and then the knock sensor, but it was still rough. I spent many hours following up on this thread, one on, and another on, as well as trying to research, when I went back to the place that did my timing belt and asked them to make sure that it was still on right.

They told me that some part of the timing belt kit had been faulty and they fixed it for me. I just wish that it had not happened before I fixed the knock sensor, or while I was in summer school.

Original post:
I decided to take my car to get its oil change and have them check out my air conditioner on my way to school and hope that they would do something about my problems locking my driver's door besides tell me that everything was fine.

My check engine light was on and my Ultragauge screamed at me for the half-mile drive. It only would have taken me a moment to get the code, but believed that the mechanics would insist on inspecting it or whatever they do--for a hundred dollars, apparently.

They say that it is a faulty knock sensor, so now I am trying to track down my paperwork to see if my repair plan will cover it. I called the dealership and they told me to drive over.

Yes, let me drive fourteen miles from my mechanic to a dealership with a check engine light.

My mechanic said $475. Autozone has one for $78.99 and according to this video:, it only takes moments to install.

gone-ot 04-30-2013 09:56 AM

That "Bolt-thru"knock sensor is great, unfortunately, most units are actually "bolt-like" devices and always seem to be located in impossible-to-reach locations.

Xist 04-30-2013 10:43 AM


Originally Posted by Old Tele man (Post 368898)
That "Bolt-thru"knock sensor is great, unfortunately, most units are actually "bolt-like" devices and always seem to be located in impossible-to-reach locations.

That does not sound fun. Would it help that I have a universal joint?

Xist 04-30-2013 02:32 PM

I had not heard back from the shop, so I called. AC hose, power steering hose (old problem), and knock sensor, $1,570 and none of it is covered by my $1,600 service plan. Plus, it is at 103,600 miles, and at 105,000 I am supposed to replace the timing belt and all of that. Their estimate was $800-850. Call it $830 for an even $2,400.

I think that is about one year's pay in the National Guard.

Xist 05-10-2013 12:11 PM

I have had intermittent problems with my driver's door lock. I went over one time just for that. I told them that I could not lock the door while it was in their parking lot and they chuckled. Yesterday it was acting up again, so I stopped by, satisfied them that there was a problem, and resumed my day. I dropped it off when they opened and it looks like they decided that most of it was bad. Man, I forget now, two parts and the handle. The service plan is covering the two parts, plus labor and tax (which are minor), but there is a hundred-dollar deductible, and the service plan guys said they did not cover the handle. I told the shop that it was specified in the brochure, so we will see.

I will end up paying sixty percent of a $300 repair and I still need to fix the AC hose, power steering hose, and knock sensor, plus it will need the timing belt and all of that soon.

mwebb 05-10-2013 12:57 PM

i have not worked on subaru in about 4 years
if i remember correctly the knock sensor is in the block to the left of center and

My Mom could replace it without too much drama
it is important to clean the mounting surface and to torque the fastener to the correct torque

a fault set for the knock sensor will greatly reduce your FE and overall enjoyment of driving the car -

my mom could also replace the timing belt , i can do that with my eyes closed literally ....
so even a pure rookie such as your self should be able to replace it on a saturday , begin to end with a few tools and correct instructions

Xist 05-10-2013 05:55 PM

Well, this knowledge will make everything that much more embarrassing if things do not go well! :D

Xist 06-08-2013 03:45 AM

My car is at about 104,965 miles and the timing belt is due to be replaced at 105,000. As I mentioned, my shop gave me expensive estimates for the power steering hose, AC hose, knock sensor, and timing belt, and then charged me $150 more than they had estimated to fix my driver's door lock.

Then I moved. That shop is half a mile from somewhere I no longer live, so obviously I need a new shop. I just felt obligated to do all of these repairs and the maintenance (timing belt and water pump) myself to save tons of money (if I cannot afford the shop, then they never get repaired, and eventually it costs more).

I planned on starting at Autozone at 6am and hoping to to finish before good old Sol murdered me. However, it will be 109F, so I figured that I would go with U Fix It Automotive - Do It Yourself, and Do It Right! and pay to use one of their bays.

I had hoped to order everything through Autozone, pick it up in the morning, and have one long and exhausting, but productive day.

It says that I need to order in-store.

I guess that I should have planned this in advance.

I ended up on My old shop estimated $800-850 to change the timing belt, but the one repair I approved cost 40% more than they had quoted. AutoMD estimated $725.50 from a dealer and $631.90 from a shop, so I put in everything else:

Dealer Costs
$1,424.82 Time 8.3 hrs
Rate $103.00
Labor $710.70
Parts $584.13
Other $129.99

Shop Costs
$1,260.62 Time 8.3 hrs
Rate $85.00
Labor $586.50
Parts $584.13
Other $89.99

DIY Costs
$584.13 Time 10.6 hrs
Rate NA
Labor NA
Parts $584.13

So, $840.69 over a dealer and $676.49 over a shop, but I would pay at least $240 for the bay and tools, so $600.69 and $436.49 respectively.

Well, it cannot hurt to get estimates...

Xist 06-09-2013 02:29 AM

Captain's log: Supplemental.
When the shop opened, I called, and talked to someone who put me on hold while he looked up my estimate. After a few minutes someone else picked up and did not seem to have any idea about anything, so I asked for an estimate for a timing belt, knock sensor, AC discharge hose, and power steering hose. He took my number, said that he would call me back, but never did.

Men! :D

I reserved a car, but canceled because I have not seen my credit card since I first received it. I check my balance every day, nobody is using it, I just cannot rent a car, so I asked a friend to drive me, except that she wanted to discuss it at 1:30am, when she was at work, and then at 6:30am, when she got off work.

The shop did not open until eight!

We met up somewhere for breakfast and I kept thinking about the Pep Boys across the street, so I called while we waited for our orders and I dropped off my car. The young lady seemed nice, although she seemed to question the prices from my previous shop, as well as some of their practices. She called me back in the early afternoon with the following update:

The timing belt was progressing well.
I actually had two leaking power steering hoses, a couple of hundred each, so I told her that I would leave it.
The knock sensor was actually performing within specified parameters--my engine was knocking! Her manager got on the phone and explained that a three-stage (de-carbon?) engine treatment usually fixed knocks.
She actually kept saying that the AC hose could wait. I think that she wanted me to have my car back after replacing the timing belt and fixing the knock.

What is frustrating is that I decided to have a professional fix my car so that I could study.

I spent the morning taking care of my car, then my mom drove me to my sister's, where my nephew had his second or third birthday party. I just wanted to see my parents. Then I drove my niece and nephew to the airport to see my other sister, who had a layover in Phoenix. I dropped off each kid, pulled my bike out of my sister's garage(!), drove home, and a friend came over for cake and ice cream for her birthday.

All of those things are very good, but I need to work very hard to improve my grades. I already started off poorly!

Xist 06-09-2013 07:31 PM

$901.21. I need to call back about the power steering. I actually have two bad AC hoses and they cost a couple hundred each. My knock sensor was not bad, my engine was knocking, but they took care of that. That was more than the first shop had estimated, but I do not have any confidence in their estimates, and they wanted $470 to fix a knock sensor when the engine was knocking.

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