1998 OBW with original HG's

[BluetoE]

I just purchased a 98 OBW about 3 weeks ago. The car has 173,000 miles on it and is still on the original HG's. From what I have read on the boards, is it true that only 15-20% of the 2.5L DOHC engines have the HG problems?

 

I owe you guys so much already btw. When I purchased the car it needed a little bit of work. It had the "rear end slips while making slow turns" torque bind issue. So far I have drained the ATF twice and after the first time the problem stopped completely. I will be draining it 2 more times over the next week or so to get it as clean as possible without performing a "flush". The mechanic at the local Subaru dealership told me it would be $1700 to fix the torque bind. So far I have about $30 in the problem and it seems to be fine. Thanks a lot for all the great info about that problem!

 

Also, when I purchased the car the CEL was on and the code was for the knock sensor. The friend of mine that I bought the car from had a stack of "SubaruBucks" in the glove box, so I cashed one in and grabbed a new knock sensor from the dealership. They had to order it and charged me $125 for the part, but with the $100 coupon it cost only $25. So far so good. Once it came in I removed the faulty sensor and went to install the new one. Let's just say the placement of that sensor is kind of a pain to get to. I read on this forum and a few others about "relocating" it to a less noisy part of the block. I installed it below the throttle body and reset the CEL. The light is off now and the timing is no longer retarded. What is the general consensus on relocating the knock sensor? If it is a huge deal I can put it back where it belongs.

 

Thanks again for all the great information on these boards. You guys rock!

 

I am absolutely in love with this car btw...

[Olnick]

From what I have read on the boards, is it true that only 15-20% of the 2.5L DOHC engines have the HG problems?

 

No one really knows. It's just a WAG. If anyone really knew it would be SOA/FHI, and they're not talking!

 

Other than that it's a great car. Here's to many happy miles of motoring on yours.

[idosubaru]

that percentage is not accurate from a statistical view point. i think it came from a german no-name website, it's as good as me making up a number based on my experience, which isn't accurate either.

 

how do you know without a doubt that yours was never replaced anyway?

 

can't say whether or not it really matters, but i've never found the knock sensors hard to replace. i understand they could be easier, but never had much of a problem replacing them in 15 minutes myself so not worth it.

[Olnick]

Oh . . . and welcome to the Board. You found a good place here!

[BluetoE]

Thanks for the welcome! There is a wealth of information here and it has already saved me tons of time and $$$!

 

As far as the HG's are concerned, I have all of the maintenance records. The timing belt has been changed at 70k mile intervals. It will be due for another one at 210k as far as I can tell. No overheating issues at all so far and the car has been very well maintained.

 

The knock sensor placement is about 10 or so inches below the throttle pullies (I'm not a mechanic and don't feel like looking up the exact part description ) When I go to install the new one, I put the bolt in my socket with an extension and put the sensor on the bolt. They tend to fall out of the socket on the way down to the hole where the bolt goes. Perhaps there is a magnetic socket that would hold it in place? I had just read about people purposefully moving the knock sensor to a "quieter" location on the block and was wondering how people felt about that. A friend of mine who is a Subaru guy and a member of this board told me that the engineers put it down there for a reason and I shouldn't move it to the top of the block. I was just looking for more input. The car is running great now with the sensor moved to the top.

[aircraft engineer]

Thing is that it detects the knock by a vibration frequency converting to a piezoelectric output.

 

It MIGHT not make a difference where it is now, but I have to admit that the Japanese are somewhat anal about making things work "just so" and it might not pick up.

 

I know that I've been having the occasional "knock sensor" code out of mine and I guess I need to go get another one (auto parts store - $115)

 

I can't "hear" any knock sound but it might be there - either that or a bad connection

 

to make a bolt stick in a socket, try a small piece of electrical tape inside the socket and push the bolt in to hold it there. When you pull the socket off 1 of 2 things will happen - the socket will pull off the bolt (what you want) or the socket will pull off the extension (and then you will need to go fishing with a pair of long nose pliers.)

[WoodsWagon]

I ran an EJ25 with a relocated knock sensor for a while. It would detonate on hard accel, and when we pulled a trailer with it it would detonate like no tomorrow. If you have a new sensor, put it in the right spot, use a 10mm with a long 1/4" drive extension, isn't that hard. The pigtail has to be at a 45 degree angle to the centerline of the block. Only knock sensors on the way out need relocation. It's a stop gap to get the code to go away and not spend money.

[Rooster2]

I ran an EJ25 with a relocated knock sensor for a while. It would detonate on hard accel, and when we pulled a trailer with it it would detonate like no tomorrow. If you have a new sensor, put it in the right spot, use a 10mm with a long 1/4" drive extension, isn't that hard. The pigtail has to be at a 45 degree angle to the centerline of the block. Only knock sensors on the way out need relocation. It's a stop gap to get the code to go away and not spend money.

 

 

It helps to have a "wobbler" at the end of the extension, just before the socket. There is just not a straight shot to line up on the bolt other wise. It is awkward, but the wobbler makes it reasonably easy to tighten up the bolt on the knock sensor.

[BluetoE]

I generally don't try to fix things that seem to be working ok, but I will give the sensor another go. Thanks for the tips about the tape and the wobbler.