1996 Volvo 850 T5 Knock sensor ???

[redbeak1]

Hello, I have a new issue. As the car turns a quarter century it seems like I will be going over the entire car part by part!!
Around 6 months ago I got a code P0326 for Knock sensor, I cleared it and it just came back again. I pulled the manifold thinking that I will replace with the new improved Knock sensor without the connectors at the sensor. I now find out that I have to splice it into the wiring harness. IPD has no instructions, and all I can find is that some people have connected it with a kit from Volvo. Does anyone know where I can find instructions?
I did find that the original connectors on the car were very corroded (green). I cleaned it with CRC. Should this be enough to fix the code? Also,besides using the CRC cleaner, is there any other type of anticorrosive electrical grease that could prevent corrosion in the future since it is a very hard spot to get to.

Also, the starter is original and still working great (148,000 miles). Since it is so much easier to get to now, should I change it as a preventative maintenance or can I still get much more out of it?

[erikv11]

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replace with the new improved Knock sensor without the connectors at the sensor. I now find out that I have to splice it into the wiring harness. IPD has no instructions, and all I can find is that some people have connected it with a kit from Volvo. Does anyone know where I can find instructions?
...

You "splice it" using the harness. Volvo used to sell a kit containing the knock sensors and the conversion harness but I don't think they do any more. The harness may still be available. But I'm not up to googling it right now, poke around if you really want to go that route. Junkyard may be another way to find one.

...
I did find that the original connectors on the car were very corroded (green). I cleaned it with CRC. Should this be enough to fix the code? Also,besides using the CRC cleaner, is there any other type of anticorrosive electrical grease that could prevent corrosion in the future since it is a very hard spot to get to.
...

Cleaning the connections should do it! It is extremely rare for the knock sensors to actually go bad. Wiring or connectors yes, knock sensors no. Or even bad ignition parts causing a knock sensor code. In fact, a fair rule of thumb is "it's never the knock sensors."

You can use dielectric grease from e.g. an auto parts store. Use it on the rubber boot surrounding the metal contacts, not on the contact surfaces themselves. For the contacts themselves, I don't know which CRC brand product you used but my preferred product for cleaning corroded contacts is something called DeoxIT D5, I bought it online.

...
Also, the starter is original and still working great (148,000 miles). Since it is so much easier to get to now, should I change it as a preventative maintenance or can I still get much more out of it?

I've never had to replace a starter on the few quarter-century old Volvos I have been running. With such low miles (148k) my vote is to leave it alone.

[abscate]

Loosen the mounting bolts on the starter one by one, remove, clean threads shiny with a Dremel, lubricate, reinstall, torque to specs. Remove the back mount on the starter, to right side of car, if you have one. Volvo discarded it later on as unnecessary.

Torque spec for starter bolts is........40Nm or 28 ftlbs

That’s a firm elbow tight ona 6 inch ratchet handle

250,000 on my original starter

[redbeak1]

Loosen the mounting bolts on the starter one by one, remove, clean threads shiny with a Dremel, lubricate, reinstall, torque to specs. Remove the back mount on the starter, to right side of car, if you have one. Volvo discarded it later on as unnecessary.

Torque spec for starter bolts is........40Nm or 28 ftlbs

That’s a firm elbow tight ona 6 inch ratchet handle

250,000 on my original starter

I assume removing the mount now makes it easier in the future when access is not that easy?
I roughly figured that I have about 15,000 starts on the starter and it's great to know that yours is still going strong since the reviews on rebuilt starters is not always positive.
Thank you!!

[redbeak1]

...
replace with the new improved Knock sensor without the connectors at the sensor. I now find out that I have to splice it into the wiring harness. IPD has no instructions, and all I can find is that some people have connected it with a kit from Volvo. Does anyone know where I can find instructions?
...

You "splice it" using the harness. Volvo used to sell a kit containing the knock sensors and the conversion harness but I don't think they do any more. The harness may still be available. But I'm not up to googling it right now, poke around if you really want to go that route. Junkyard may be another way to find one.

...
I did find that the original connectors on the car were very corroded (green). I cleaned it with CRC. Should this be enough to fix the code? Also,besides using the CRC cleaner, is there any other type of anticorrosive electrical grease that could prevent corrosion in the future since it is a very hard spot to get to.
...

Cleaning the connections should do it! It is extremely rare for the knock sensors to actually go bad. Wiring or connectors yes, knock sensors no. Or even bad ignition parts causing a knock sensor code. In fact, a fair rule of thumb is "it's never the knock sensors."

You can use dielectric grease from e.g. an auto parts store. Use it on the rubber boot surrounding the metal contacts, not on the contact surfaces themselves. For the contacts themselves, I don't know which CRC brand product you used but my preferred product for cleaning corroded contacts is something called DeoxIT D5, I bought it online.

...
Also, the starter is original and still working great (148,000 miles). Since it is so much easier to get to now, should I change it as a preventative maintenance or can I still get much more out of it?

I've never had to replace a starter on the few quarter-century old Volvos I have been running. With such low miles (148k) my vote is to leave it alone.

Thank you for your detailed answer. It gives me confidence to button things up this weekend. I will check out your anti- corrosive D5. Another product my brother mentioned is ACF 50 which is used in the aviation industry. And can be sprayed directly onto the connection without altering conductivity, resistance etc. If it's good for a Boeing 777, it should be OK for our old Volvos! I did use CRC electrical contact cleaner. But I doubt that it would protect it for a long time. Your idea to put electrical grease around the connector is a good idea. Instead of splicing, I will try to clean up all contacts and hope the CEL goes away.

[redbeak1]

Update. Surely enough, it was the corroded connectors for the knock sensors. CEL is gone. Also, while I had the manifold off, I cleaned up all the other connecters... including starter wires.Since the PCV was changed 7 years ago, I changed that also and will probably never have to worry about that again!!
Thank you all so much for your advice.

[erikv11]

Nice work!