Knock Sensor Location
#1
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
Knock Sensor Location
Are there any knowledgeable mechanics or anyone with a 2005 RL Service manual that can tell me where the knock sensor is? My dealer tells me a rodent "must have" chewed through the sub harness leading to the knock sensor. This is causing a chronic emissions code and apparently a problem with the SHAWD. They want to charge me $500+ for the repair as "acts of god" are not covered by the warranty. If I can locate the harness in question, I'm confident I can repair the disconnect myself. Any help would be greatly appreciated.
#5
the knock sensor is located in the V of the V6.
It resides under the plastic covering the the intake manifold and there is only one sensor. its deep towards the bottom of the V, and there is a simple procedure to test the continuity of the wires from the PCM to the sensor.
Its highly unlikely that a rodent chewed through O
It resides under the plastic covering the the intake manifold and there is only one sensor. its deep towards the bottom of the V, and there is a simple procedure to test the continuity of the wires from the PCM to the sensor.
Its highly unlikely that a rodent chewed through O
#7
Ok, to test the sensor, you will need to know the location of the PCM, and the test is only on one wire.
However you will need to also undo the plastic cover over the engine, and then disassemble the fuel rail to access the knock sensor to make the continuity test to verify that the wire is not severed.
So far, does this sound like something you want to do?
Because the only wire that leads to the sensor is supposed to have a 12V on it, and it grounds to the engine, so from the PCM, you may get the 12V on the wire, but to verify that the wire is intact you will need to do a simple continuity test while the car is off.
However you will need to also undo the plastic cover over the engine, and then disassemble the fuel rail to access the knock sensor to make the continuity test to verify that the wire is not severed.
So far, does this sound like something you want to do?
Because the only wire that leads to the sensor is supposed to have a 12V on it, and it grounds to the engine, so from the PCM, you may get the 12V on the wire, but to verify that the wire is intact you will need to do a simple continuity test while the car is off.
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#9
I know you want to save money, but from the description of the location, it really may be better for the dealer to handle this. If $500 is too much, you should shop around if there's another dealer in your vicinity.
#10
The One Problem of Hi-Tech Cars
This is the major problem as cars grow more technologically complex -- the difficulty of access just to perform diagnostic tests. Checking the integrity of the knock sensor wire is not itself difficult, but gaining access to the test points is a major operation. The knock sensor is actually located beneath the intake manifold, hence its removal is needed to gain access to the wire connection. This isn't a difficult operation, but it takes time and requires replacement of all the manifold gastkets removed in the process. Same thing with getting to connection at the PCM -- takes time. At dealer rates it adds up fast. Most of the cost here is just labor -- probably 80%.
Even where parts self-diagnose their own problems -- the major cost is the labor just to gain access for replacement. Maintenance access is usually not a high priority when engineers are designing today's high tech features.
After changing the fluid in the SH-AWD drive unit recently, I can see why a dealer charges $40 to $75 for the job -- the fluid costs only $18, but the job of accessing the drain and fill ports is a bear, especially if you don't have the car on a lift.
Believe me -- pay the dealer -- the amount of work you'll save yourself is worth the cost. Unless, of course, like me you just enjoy getting the job done yourself.
Fortunately, I have the time since I'm retired.
Even where parts self-diagnose their own problems -- the major cost is the labor just to gain access for replacement. Maintenance access is usually not a high priority when engineers are designing today's high tech features.
After changing the fluid in the SH-AWD drive unit recently, I can see why a dealer charges $40 to $75 for the job -- the fluid costs only $18, but the job of accessing the drain and fill ports is a bear, especially if you don't have the car on a lift.
Believe me -- pay the dealer -- the amount of work you'll save yourself is worth the cost. Unless, of course, like me you just enjoy getting the job done yourself.
Fortunately, I have the time since I'm retired.
#11
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
Thanks for all the replies. I'm not intimidated by the work. I'm just trying to figure out how much the parts will cost total before I begin. I found the knock sensor and sub harness for about $40. If the required gaskets are going to cost a another couple of hundred, then it may make sense to have the dealer do it after all. I figure the Helms Manual will help me determine the required gaskets.
#13
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
I found these exploded views online.
In this picture, the knock sensor is "10". As others have stated, it's located right in the "V".
This is a picture of the intake system. My question is, can I get a way with just removing the "2" cover (on the right) that rests on top of the main intake? It looks like it may grant access to the knock sensor.
If someone with the repair manual, can answer the above, I would be ever so appreciative .
In this picture, the knock sensor is "10". As others have stated, it's located right in the "V".
This is a picture of the intake system. My question is, can I get a way with just removing the "2" cover (on the right) that rests on top of the main intake? It looks like it may grant access to the knock sensor.
If someone with the repair manual, can answer the above, I would be ever so appreciative .
#14
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
Looks like I found another obstacle. Under the intake manifold I found this:
Based on the gasket that mates the intake to the injector manifolds they join together further blocking the ever elusive knock sensor.
So far it looks like I need:
"10" (Knock Sensor): $27.54
Sub Harness (Not pictured): $3.26
"3" (Manifold Cover Gasket): $31.18
"1" (Manifold Base Gasket): $19.08
"9" (Front Injector Base Gasket): $12.42
"11" (Rear Injector Base Gasket): $12.42
After shipping and handling fees, about $117.00. Now all I need is the repair manual so I know torque specs and such. Even if the manual costs and additional $80-$100, I'm still WELL under the $520 quote from the dealer.
Based on the gasket that mates the intake to the injector manifolds they join together further blocking the ever elusive knock sensor.
So far it looks like I need:
"10" (Knock Sensor): $27.54
Sub Harness (Not pictured): $3.26
"3" (Manifold Cover Gasket): $31.18
"1" (Manifold Base Gasket): $19.08
"9" (Front Injector Base Gasket): $12.42
"11" (Rear Injector Base Gasket): $12.42
After shipping and handling fees, about $117.00. Now all I need is the repair manual so I know torque specs and such. Even if the manual costs and additional $80-$100, I'm still WELL under the $520 quote from the dealer.
#15
The entire manifold, top cover and main body, have to be removed. Next, the manifold runners, (10), as well as the fuel rails and injectors (plus harnesses) all also have to be removed for access to the knock sensor. Do not even attempt without having the service manual (unless a well experienced Acura service tech) -- there are detailed procedures for reassembly. Personal note: the job is never, never as easy as it looks in the illustrations -- access to some of the mounting hardware sometimes is very tight and requires special Honda tools. Get the manual and study it carefully, it may be more than you want to tackle. I can tell you from personal experience Acura's are a lot more complex than a manifold removal on a small block chevy. Good luck.
#16
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
I can only seem to find the Acura service manuals on ebay. Can anyone comment on which is better, Helms or Acura? If Helms, where can I pick one up used? Maybe someone in the SF Bay Area would like to "rent" their copy to me for a few days?
#17
Originally Posted by Jackzilla
I can tell you from personal experience Acura's are a lot more complex than a manifold removal on a small block chevy. Good luck.
LOL
I remember using a wrench, crow bar, screwdriver and a scraper (for the gasket) when I changed the water pump on my college car ('78 Chevy Impala w/305 cu in small block).
I think it took my maybe an hour at most.
I wouldn't even attempt to try it in today's cars.
#18
Helms IS the official authorized publisher, as well as the supplier, of all Acura manuals. (Honda too). The manual is a three volume set. I would not attempt to use any other. You'll find it contains more than you'll ever want to know about the RL, but it's invaluable you really want to do your own maintenance and repairs.
If you can find a set on E-Bay for less than $130. (the Helms list price) grab it. Do keep in mind though that these manuals are written for highly experienced techs and do-it-yourselfers. They presume considerable automotive work experince and expertise.
If you've never removed an engine or torn one down you might not want to reconsider starting with a project like this. If you don't get everthing in the intake track back together EXACTLY right, you'll go crazy over why the engine won't run smoothly or idle correctly. Nough said.
If you can find a set on E-Bay for less than $130. (the Helms list price) grab it. Do keep in mind though that these manuals are written for highly experienced techs and do-it-yourselfers. They presume considerable automotive work experince and expertise.
If you've never removed an engine or torn one down you might not want to reconsider starting with a project like this. If you don't get everthing in the intake track back together EXACTLY right, you'll go crazy over why the engine won't run smoothly or idle correctly. Nough said.
#19
Originally Posted by Jackzilla
Helms IS the official authorized publisher, as well as the supplier, of all Acura manuals. (Honda too). The manual is a three volume set. I would not attempt to use any other. You'll find it contains more than you'll ever want to know about the RL, but it's invaluable you really want to do your own maintenance and repairs.
If you can find a set on E-Bay for less than $130. (the Helms list price) grab it. Do keep in mind though that these manuals are written for highly experienced techs and do-it-yourselfers. They presume considerable automotive work experince and expertise.
If you've never removed an engine or torn one down you might not want to reconsider starting with a project like this. If you don't get everthing in the intake track back together EXACTLY right, you'll go crazy over why the engine won't run smoothly or idle correctly. Nough said.
If you can find a set on E-Bay for less than $130. (the Helms list price) grab it. Do keep in mind though that these manuals are written for highly experienced techs and do-it-yourselfers. They presume considerable automotive work experince and expertise.
If you've never removed an engine or torn one down you might not want to reconsider starting with a project like this. If you don't get everthing in the intake track back together EXACTLY right, you'll go crazy over why the engine won't run smoothly or idle correctly. Nough said.
My brother who has dabbled and done some moderate engine work in the past tried replacing the timing belt on a 5 year old Corolla.
The engine went ka-boom shortly thereafter.
#21
Originally Posted by GoHawks
My brother who has dabbled and done some moderate engine work in the past tried replacing the timing belt on a 5 year old Corolla.
The engine went ka-boom shortly thereafter.
I am a member of SEMA (the big car show in Las Vegas every year) . I used to design and sell specialty parts for Hondas and Acuras. I used to race cars (including an Integra. Mazda RX7, Toyota MR2, go carts and shifter carts) and did most all the work myself - including engine stuff, and work and I would NEVER attempt what you want to do unless I didn't need to drive the car for a few weeks. one little gremlin could take days of intensive testing to locate and that's with the software and hardware to trouble shoot.
When I sold my 06 I gave the new owner, a friend, the Helms manuals otherwise I would be glad to scan diagrams and instructions, but I'm betting that there are at least two or three Acura specific tools used in the removal and reassembly. Seldom can conventional tools replace factory designed tools. I bought one factory specialty tool for the Integra (and trust me I have a garage full of all kinds of tools but needed this one) and it cost almost two hundred dollars. I eventually old it to the local Honda dealership for about $20 and a some good will.
If you figure your labor for as little as $10 per hour, you will still lose money. If you get the manuals and see that you need specialty tools, call an Acura dealership to find out their cost. Even at jobber discounts I willing to bet that you will pay more for the two or three tools than the entire cost of taking it to an Acura shop.
If you have read any of the posts about how frustrating it is just to change the air filter then multiply that by HUGE amounts and you will have a small clue about what you are probably getting your self into.
The other side of the coin. It may be as simple as removing about 2 dozen bolts and a few clips, but as was explained above, it ain't no Chevy short block.
If you are bound and determined to do the work and not have it done by an Acura shop, buy all the parts you think you will need and take them to a Honda specialty shop (usually found in the Yellow pages) and ask them how much for labor. But if you don't have all the parts, plan to leave you car there for a few days - up to a week until the rest of the parts arrive.
Why am I so adamant about just saying no, because I've been where you are and there are plenty of ways to save the cost of taking it to Acura, but there are times when you really need to leave the job to the experts. If your pricing of the parts is suggested retail (not a discount via internet) then you can figure $250 to $350 of the shops estimate is for labor and they have the tools to do the job and the mechanics who are trained to do it correctly (or at least HOPEFULLY they are trained to do it correctly) and are still planning on 3 or more hours of shop time.
Okay, off my soap box.
The set I bought from Helms was 3 manuals (actually I had more because I bought the electronics and body manual, too) so I have no clue what the Ebay 2 manual setup is.
Anyway, a sincere wish for best of luck and circumstances if you go for it yourself.
Ben
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Julio C Zavala (01-06-2015)
#22
Originally Posted by Benush
The set I bought from Helms was 3 manuals (actually I had more because I bought the electronics and body manual, too) so I have no clue what the Ebay 2 manual setup is.
Ben
Ben
#23
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
NP, all very useful information. The ebay auction is just for the 2 service manuals. I think I'll pick up the service manual to definitively tell me whats involved. If I find I'm out of my depth, It only cost me $65. If anyone else has one on hand and would like to save me $65, I'd gladly buy you a beer next time I see you.
#24
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
5 months later, I’m all done with the repair. After everything is said and done, the $500 quote was absolute robbery!
For my specific problem, I removed the air cleaner from the throttle body. Then removed all visible hoses and harness plugs. I removed the intake top plate. Unbolted and removed the intake assembly. Removed the front fuel rail which gave me access to the knock sensor through the gaps in the intake base. Using needle nose pliers, I was able to remove the rat chewed harness connector from the knock sensor (the sensor itself was fine). Using the same method, I fished the replacement sub-wire in place and reconnected it to the knock sensor. Then I put everything back together in reverse order.
All I needed was:
Lower intake gasket: $30
Intake top plate gasket: $35
Knock sensor sub-wire: $6
Torque wrench rental: $10
1 week eautorepair.net access (online repair manual): $10
Total: $91 and about 2 hours time
For my specific problem, I removed the air cleaner from the throttle body. Then removed all visible hoses and harness plugs. I removed the intake top plate. Unbolted and removed the intake assembly. Removed the front fuel rail which gave me access to the knock sensor through the gaps in the intake base. Using needle nose pliers, I was able to remove the rat chewed harness connector from the knock sensor (the sensor itself was fine). Using the same method, I fished the replacement sub-wire in place and reconnected it to the knock sensor. Then I put everything back together in reverse order.
All I needed was:
Lower intake gasket: $30
Intake top plate gasket: $35
Knock sensor sub-wire: $6
Torque wrench rental: $10
1 week eautorepair.net access (online repair manual): $10
Total: $91 and about 2 hours time
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Julio C Zavala (01-06-2015)
#26
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
-- Apparently it's not an uncommon problem. While searching for a fix, I found quite a few stories of the same thing happening in other cars. The thing I find odd is the presents of the "sub-wire" in the first place. It's almost as if Honda knows that rodents like to chew out just that section of the harness and designed it to be replaceable. I think the engineering dollars would be better spent keeping the rodents out of the "V" area in the first place. But then, I guess the dealers wouldn't be able to gouge you for $500 to replace a $5 wire.
#28
Thread Starter
Cruisin'
Joined: Aug 2003
Posts: 19
Likes: 1
From: Morgan Hill, CA
Directly under the throttle body assembly, the "V" is wide open. Easily accessible for a small animal. I also read somewhere that rats can squeeze through holes as small as a quarter. Something to do with a collapsible skeletal structure, I believe.
#29
I can definitely attest to a rat chewing the sensor. Happened to me too. I tried fishing the sensor from inbetween the lower intake, but the plastic part of the sensor came out/broke with the plug attached. Now I have to go through the trouble of removing the lower intake runners, and the power steering pump as well. Such a PITA.
#30
So here's the image of the chewed up knock sensor. I still have yet to get the lower intake runners out becuase of a seized 12mm bolt, that just gets rounded when I try to turn it with a wrench. Gonna have to get me the extractor wrenches. So annoying. Did they not put antiseize on those bolts from the factory? I believe they're only torqued to 12 ft lbs anyway, but two of them are tight as a motherfucker.
Has anyone done this? Taking out the intake runners? I looked up on youtube and seems that they just need to take out one side for the J35, to access the knock sensor, but I cant, it just gets stuck, no clearance for them to come out all the way. I read that the J35a8 (which is on the RL and the old TL Type S) is different in that the intake runners are lower in the engine. It wouldn't seem feasible to have to take out the heads to access the knock sensor because then that includes having to remove the cams, timing belt and all that. Surely Honda didn't engineer it to be like that just for a knock sensor...
Has anyone done this? Taking out the intake runners? I looked up on youtube and seems that they just need to take out one side for the J35, to access the knock sensor, but I cant, it just gets stuck, no clearance for them to come out all the way. I read that the J35a8 (which is on the RL and the old TL Type S) is different in that the intake runners are lower in the engine. It wouldn't seem feasible to have to take out the heads to access the knock sensor because then that includes having to remove the cams, timing belt and all that. Surely Honda didn't engineer it to be like that just for a knock sensor...
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