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 cartalk.com, and another on SubaruForester.com, 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: http://www.youtube.com/watch?v=hgsrk0t7NE4, it only takes moments to install.

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?

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.

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.

Diy
 

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

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 109°F, 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 automd.com. 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...

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!

$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.

Okay, Nancy told me that I needed to replace two air conditioning hoses, not power steering!

My roommate told me to purchase bottles of power steering fluid from the 99¢ store, but I do not like the idea of dripping power steering fluid all over Arizona. Also, I told him about power steering fluid saturating the alternator belt on my Prelude and my alternator going out.

Some shop also convinced me to replace my rack and pinion, also claiming that power steering fluid ruined it.

He told me to charge up my refrigerant, that is what he does every six weeks.

I really do not like the idea of dripping that!

I found "A" AC hoses on car-part.com starting at $45, although I wonder what the other hose was, if two were leaking.

The power steering hose starts at $40 and one place has both!

Should I order them? I just looked at my repair manual and did not see anything relevant.

My roommate is trying to convince me to pour freon into my leaking system today. I keep telling him that I need to study for a test and he just asked "What does that have to do with anything?"

Well, my roommate is upset because I went and bought car parts instead of putting my car on power steering fluid and freon dialysis. I just decided to track down both AC hoses on car-part.com, so I went to pull up a Subaru supplier to look at the diagram. They offered the parts for less than "MSRP" and the Google ad gave me a coupon code for an additional 15% off. I looked at several other sites, one had lower prices and one charged less for shipping, but the coupon code was the deal maker, at least since I did not even know how to find the part used.

"Full price" was $762.22, but I got the parts for $501.47 before shipping and handling ($71.75).

I guess that I need to find a good temp agency after finals. I have nine business days before two days of drill and fifteen days of annual training and nineteen business days before returning to school. I was supposed to work for my father, but that is not going to work out.

I want to put in my hundred hours of observation so that I can get my Speech-Language Pathology Assistant license. If everything else goes according to plan, I need that by January in order to apply for the Master's program that I want, but I would need to get out of annual training, and I do not know how likely that would happen.

The other day I needed to purchase a few different things and study for a test. I need all of the help that I can get on those. I hate Walmart, but I decided to do one stop and be done instead of going to multiple stores. So, I bought food, duct tape, and bike stuff, so I have been riding to class in the morning. After class I rode to a bike shop to purchase a lock and some other stuff.

It added up and I said "I'm running out of money!"

"It is better than a car!"

I need a hug... preferably from someone rich and generous.

Who is saving the world now, Prius?!
 

An hour before my second class, I got my bike out of my car, but the tire was flat. I just patched it the other day and it had been fine since.

Of course, everything that I needed to repair the tire was at home, so I started walking, and it took a couple of hours to be on my way--right about when class was ending!

I rode home eight miles, not having gone further than half a mile in years. My backpack was pretty heavy and I sure was tired when I got home!

My car needs engine work...

Well, this is my tenth post in a row. If I just hand over my money to Pep Boys, I will nearly be out of money. I really hope that I can get some feedback because I am really stressed!

I started this thread reporting that I took my car to my previous shop for a P0325, Knock Sensor Circuit Malfunction. They wanted nearly $500 to fix it. My new shop said that I just needed some engine treatment and the code went away for a week and a half, but it came back yesterday, and now my engine ran a little rough.

I heard what sounded like a very rough engine and it was my car. The technician came in saying that I was only running on two cylinders, but that sounds like far worse of a problem than I had been experiencing. They say that I need a $266.80 valve adjustment, which is all labor, but the total is $300 more than that:

Engine Light diagnostic: $44.99
Shop Fee: 35.00
Tune up package
Remove and replace spark plugs: 60.03
Additional access time - remove: 64.20
and replace spark plugs:
NGK Spark Plugx4: 9.96
Adjust Valve Clearance: 266.80
Pepguard Limited Extended Labor: 58.65
Warranty
BWD Custom fit ignition set: 36.39

Parts: 46.35 Labor: 436.02 Other: 93.65 Tax: 6.55 Total: 582.57

Of course, my roommate who is upset that I am not continually pouring fluids into leaky system butted in and said the entire thing is preposterous. Problems with cylinder firing are invariably the result of bad spark plugs and\or wires.

Well, they say that I need to replace those, which cost $46.35, the least expensive entry in the entire estimate. They just want to charge $124.23 to replace them.

Why don't I replace them myself and see if that fixes my problems?

They say that if the valve clearance adjustment does not fix the problem then I need new cylinders and valves.

Regretfully, I have a "service plan:"I cannot imagine that it would cover a valve clearance adjustment and they would only cover cylinders and valves "if damaged by the failure of an internally lubricated part."

So, ride my bike eight miles tomorrow, replace the spark plugs and wires, and hope that it is enough?

Sounds like your mechanics are more interested in throwing parts (which is your money) at the problem and hoping they fix it than troubleshooting.
How many miles does the car have on it? Have you checked/posted on any Subaru forums for help?

Vskid3, thank you for your response. Hopefully any further notifications do not go to my spam folder!

The car just hit 105,000 miles after I had them replace the timing belt. I posted on subaruforester.org, but my response notification went to my spam folder. "crewzer" wrote:

I corrected my posts. It was P0325.

I also posted on cartalk.com and I could not find that notification in spam. I think that it was lost to the ether--or never sent:

I arranged for a ride tomorrow morning so that I can replace my spark plugs and wires. I could have ridden my bike eight miles each way, but I cringed at the idea of carrying all of my tools on my back!

Well, I am pretty sure that I have confirmation that my problem got worse after Pep Boys got their hands on my car, I only had the one code, P0325, and then they told me that I had two cylinders misfiring, yet I did not have any of the following:

P0301 Cylinder 1 misfire detected
P0302 Cylinder 2 misfire detected
P0303 Cylinder 3 misfire detected
P0304 Cylinder 4 misfire detected

What in the world am I supposed to do about this?!

Reading through the Subaru forum, people keep saying "If you get a bad knock sensor code, replace your knock sensor!"

They mentioned finding them cheap on eBay. I found one for seven dollars, with free shipping! There is one on Amazon for $12.50, also with free shipping.

I looked at several Subaru parts dealers and I would have ordered from one, had I not wanted to do this tomorrow (today (in a few hours)).

Well, it was "today" when I started looking.

I looked at local auto parts places until I decided on O'Reilly. They had the knock sensor, spark plugs, and wires, and I also ordered a spark plug socket and a torque wrench. I read that knock sensors were easily damaged by incorrect torquing.

I also read that they are sensitive to orientation. That sounds fun.

Well, I am going to try to get some sleep. It seems like all that I am doing is sleeping and trying to figure out how to take care of my car.

My finals are on Friday.

I was not able to work on my car and I am not sure when I will be able to.

I asked a friend to drive me, but it seems like everything takes twice as long when I have "help." At 8:27 I received a message from O'Reilly informing me that my parts were ready. I called Pep Boys at 9:05 to say that I would be picking up my car, talked to the guy at O'Reilly, who said to change the spark plugs and wires and see how my car ran, but when I arrived at Pep Boys at 10:55, they said that they did not know that I was coming, my car would not be ready until 12:30.

I had already lost too much time. I needed to go home.

Hopefully I will have time to work on it in a few days.

Apparently, Pep Boys ran down my battery. They also got my floor mat all dirty. I actually still had the paper one from my old shop, which they removed, and then tracked grease into my car. I had error codes P0301 and P0303--cylinders one and three misfire, but I changed the spark plugs (and air filter) and the codes are gone, but the engine is still running horribly. I guess that I will get a video of it shaking, it is bad!

I had Autozone charge my battery, but they said that it was bad. It is from AAA and says that it has a three-year warranty, while AAA says that the average battery life in Arizona is twenty-two months. There was a code on the sticker, 1108, which one guy said meant that it was made in August of 2,011, while the other said that it was made in November of 2,008, but I told him there is no way that it would have lasted five years.

I ran the car while I finished up.

I never got any error codes, though.

The girl at Autozone told me to go to the closer Pep Boys and tell them that I took my car to the other location, where they made my problems worse, and I needed to know what they were going to do to fix it.

Mine's doing the same: running horribly rough and throwing P0302 & P0303 all the time, and new plugs didn't fix it. The ignition switch went bad a while ago and now the clutch is going.

Everything's piling up and while I was hoping the Bobsled would see 250k, it'll hit 207k in a few days. Not looking good for its future. :(

Charlie, I am really sorry about that. Good luck!

Someone on subaruforester.org suggested that the faulty knock sensor is causing the misfire. Is there any possibility of that?

Ive worked at 3 major automotive dealerships and I can attest that if you take it to Subaru you will be fixed. Little trick is ask to talk with a tech if the ramble off with solid facts ask for them by name when you bring it there. You can spend your 75 bucks an hour on a oil changer, or on a specialist even at the dealership so know who works upon your ride. look for titles like senior master or world class and minimum shop certified master mechanic.
These titles have certificates also which you may ask to see.

JustMe, thanks for sharing your experience. If the only Subaru dealership in the valley were not over forty miles away, I might just have gone already.

I looked around their web site. I guess that it makes sense that they would not list their employees, although I did see Peoria Subaru | Vehicles for sale in Peoria, AZ 85382, which was interesting. I do not know how thorough that chart is, if there are other local chains that charge less, and if there are other common services for which they would charge more, but I do not remember seeing a chart like that before, so that is something.

My dad has offered to loan me his F-150. It has been sitting all year (he bought it for a friend, but needed to take it back after the friend drove 100,000 miles in twelve months). He hates having it sit and depreciate, although it would depreciate faster if driven.

He also worries about me not having air conditioning in Arizona.

I have good parents.

Well, I replaced the knock sensor. That was easy, but it did not seem to fix anything. I did more research and wondered if my coilpack was bad. I went back to O'Reilly and the guy told me to drive until I got an engine code.

Sixty-five miles later, the light came on a few times, and it blinked for a while, but it always went away before very long. My Ultragauge showed Pending Codes P0301, P0303, and once, P0304--all at the same time!

I was not driving down the highway on one cylinder!

He told me to ignore everyone that was not in an official Subaru forum and when I talked about taking it to a Subaru dealership he told me to take where he took his two Subarus.

I think that I need to stop listening to anyone without Subaru stitched to their clothing.

The main problem is trying to indirectly diagnose the car. A Subaru tech is going to start at the same place as everyone else, he'll just be more likely to troubleshoot it faster and have whatever the needed part is. Since he's charging for the diag time, he'll spend the time actually testing things instead of selling you a guess.

Just yesterday I talked to a guy who has a check engine light. The forums tell him he needs a short running valve actuator- a $200 part that probably won't fix his problem. I've got it, but I also know that it's quite likely he's going to need a $700 plenum instead, as well as assorted gaskets and hardware. Now, we can't make a bad situation less bad, but at least I could stop the guy from slapping in a $200 part that wouldn't fix it or get him any closer to knowing what will.

well, it turns out that I can't. He just showed up and bought it. I'm going to save his VIN on my screen because he's going to be calling again soon. :confused:

Could you have told him you considered that an unlawful order? :/

Don't reinforce failure; failure reinforces itself. He got his $200 actuator because he didn't want to pay someone to look at it. Now he's spending $200 on a hunch to narrow down one possibility from the list of possible problems.

Since my last post I had another guy come in, saying he needed a knock sensor and gave me a piece of scrap paper that had "the code" on it. I explained that his car didn't have a knock sensor and that what he had wasn't a trouble code but was in fact the part number for a knock sensor. For a car with a different engine. So he bought a TPS and a MAP sensor, priced out a PCM and got an appointment next week to have it looked at. Because he doesn't think the $100 he's spending today is going to fix it. I did tell him that I wouldn't order the PCM until one of my techs told me that it was the problem, though. :confused:

I try. Really hard. I told each of those guys that I'd happily sell them anything they wanted to buy, but I'd be happier only selling them the parts they actually needed. They bought the ones they wanted, instead.

There's a lot of money being spent! And it didn't solve the problem :S

have you checked on Subaru specific message boards? I've always had excellent luck with Fords and message boards.


And you still need to do timing belt.

Here is my thread on the Subaru Forester forums: ('98-'00) P0325 on a 99 Forester "running on two cylinders" - Subaru Forester Owners Forum

I had Pep Boys do the timing belt and they told me that I did not need a knock sensor, just an engine treatment, and I was very happy when they did not charge me for it. However, after two weeks, the error code came back, and my P0325 changed to a P0301 and a P0303 (from faulty knock sensor to cylinders one and three misfire) and they wanted to charge me $280 for a valve clearance adjustment and $125 on labor for replacing the spark plugs and wires.

I replaced those myself, along with the knock sensor, which was cracked. My engine is running just as poorly as before, so I am wondering:

1) Did they install the timing belt wrong?
2) Did they mess up something diagnosing the CEL?

The car was running a little rough when I went back, but I do not think that it idled as poorly--it shakes the entire car!

If the timing belt is installed too far off, the engine will just destroy itself.

If it's a tooth off, it will run poorly ... but they generally won't start at all if the timing belt is off just a bit.

I went to the nearer Pep Boys and the General Manager took a while to talk to me, explain things, look at my car himself, and he said that he really thought that the timing belt was off, but since it ran fine for a week and a half, I guess that it somehow slipped, although it is curious that it coincided with my Faulty Knock Sensor code, although I guess that a slipped belt could cause the code.

The GM asked me to go back and give the first store a chance to make it right. I think that I came in about 9am and I called them before they closed. They said that they started on my car, but were still looking at it.

I have had more confidence...

I called back forty-eight hours after dropping off my car and the manager said that my timing belt tensioner went bad, so they will fix it this afternoon under warranty.

Good thing that I did not agree to their $265 valve clearance adjustment or $125 spark plug and wire replacement labor fees, but this was a huge waste of time and a very unnecessary distraction.

Okay guys, thank you for your input. I just got my car back and Bacon is driving smoothly again. The knock sensor had been bad, but either the mechanics did my timing belt wrong, or they used faulty parts. Hopefully that is the end of all of this.

Your going to start riding a bike? If not it's just the end of this chapter in a book titled owing cars.
Glad you got finally got it fixed.

I already started riding a bike.

I just read the entirety of your saga and couldn't help but think that you were being screwed over repeatedly. I realize in reading your posts that you are swamped with school and the problems with your car. Once you get into your masters and maybe if you are lucky things will settle down you might look into taking a community based basic automotive repair course.
I think with a little more "learnin" you could have realized that an incorrectly installed timing belt was causing so many of your false codes.
I hope that Bacon behaves it/his/her self for a time so that you can get back to your studies.