Our '05 Tahoe has an oil leak. Its been going on for quite a while. I was quite confident it was coming from top side, and have been monitoring it closely. I'm about 99% certain its the back side of the valley pan. So with that said, I'm going to be doing intake manifold gasket and valley pan gasket. We don't currently have any knock sensor issues, but while I have it apart, I figure I might as well change those as well as the seals. Looking online and at Rock auto, I see Dorman brand knock sensors. I've had good luck with Dorman brand items over the years, but are thse any good? And do I actually need a new harness as well? I suspect not. Just trying to finish up my list of parts I'll need so I can place my order. Not worried about oil sending unit as its newer, and not wet around the area. I'm also seeing this kit. Wasn't sure if its any good or not...
Advice on knock sensors
- Thread starter Blk00ss
- Start date
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mattbta
Full Access Member
Sensors OEM only for me. Most do the harness at the same time, for good measure. However, OEM harness was unobtainium for me when I was doing them, so chinesium it was. I probably didn't need a new one, but I was in there and at the time it was the one/only time pulling the intake. Now i've done it 5-6 times...lol
Do you know if Delphi is OE? I didn't notice AC delco, but saw Delphi and I know Delphi is sometimes OE
Scottydoggs
Full Access Member
the leak is likely from the oil pressure sending unit. its mounted in the valley cover rear driver side.
Tonyrodz
Resident Resident
I've had great luck with Delphi knock sensors in my 03. 0 issues.
Its not. As I stated, its not only new (I know where its located, I changed it), its completely dry all around it. I've cleaned back there and taken pics every few days to watch how the oil leaks. Its coming from a smidge up and forward before the pressure unit. Its also grimey on the front tside of the intake as well. Also, valley pan leaks are not uncommon on the 5.3
Same. I replaced sensors and the harness with AC Delco. Though the harness was a bit tough to locate.
drno4
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Been there and done what you're doing ('03 Denali XL 6.0).
I would highly recommend OE only for the knock sensors and harnesses. I buy almost everything from Rock Auto but like you couldn't find them there when I did our job so I went to Amazon for those. Your parts may vary, but here are the sensor and harness P/Ns for my rig:
Genuine GM 12601822 Knock Sensor Wire
AC DELCO 213-3521 OEM Knock Sensor
Here also is a repair video I found helpful:
In the video, you'll see some old gasket maker on a portion of the perimeter of the knock sensor cavity. I would have scraped and cleaned that off had I been them, being careful not to get any old gasket flakes into the sensor cavity (plug it with a shop towel).
As I did on our rig, I used new red high temp gasket maker on roughly the same portion of the perimeter seen in the video (NOT the full circumference).
As for your gaskets, I only use/trust FelPro for all our family's vehicles and have never been disappointed.
Hope that's helpful. Blessings on your task, my friend!
I would highly recommend OE only for the knock sensors and harnesses. I buy almost everything from Rock Auto but like you couldn't find them there when I did our job so I went to Amazon for those. Your parts may vary, but here are the sensor and harness P/Ns for my rig:
Genuine GM 12601822 Knock Sensor Wire
AC DELCO 213-3521 OEM Knock Sensor
Here also is a repair video I found helpful:
In the video, you'll see some old gasket maker on a portion of the perimeter of the knock sensor cavity. I would have scraped and cleaned that off had I been them, being careful not to get any old gasket flakes into the sensor cavity (plug it with a shop towel).
As I did on our rig, I used new red high temp gasket maker on roughly the same portion of the perimeter seen in the video (NOT the full circumference).
As for your gaskets, I only use/trust FelPro for all our family's vehicles and have never been disappointed.
Hope that's helpful. Blessings on your task, my friend!
Richyukon2001
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I would use OE for the knock sensors. MAKE SURE YOU FOLLOW THE TORQUE SPECS! I did not the first time had to the job 2x. I have had mixed results with Dorman. Also change the harness.
drewtx154
Member
Maybe a lil late in the topic but I just did this job a few weeks before you made this post I went AC Delco for both sensors and harness... I got the harness off Amazon Genuine GM 12601822 Knock Sensor... https://www.amazon.com/dp/B00F676FH4?ref=ppx_pop_mob_ap_share
Sensors from Summit Racing part # ADO-213-3521
Went with Mahle valve cover gaskets and Felpro on valley cover and intake man. Was surprised to find out that my knock sensors weren't even connected to the harness once I got down there. Have had zero problems with any of these parts since...
Sensors from Summit Racing part # ADO-213-3521
Went with Mahle valve cover gaskets and Felpro on valley cover and intake man. Was surprised to find out that my knock sensors weren't even connected to the harness once I got down there. Have had zero problems with any of these parts since...
Logani
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Glad it worked out for you. I did this about 2 months ago and the codes keep coming back. It's probably my fault for going cheap. I used a cheap kit from amazon that came with off-brand sensors and harness for around $22. I did my homework AFTERwards, unfortunately. Lessons learned. I'm about to order parts again. Question, Drew, why did you go with sensors from Summit? Isn't there a $35 OE sensor on Amazon? Just curious. Also, is it ok to reuse the intake gaskets? (Again, they're 2 months old).
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Scottydoggs
Full Access Member
you should be ok reusing them intake gaskets. as long as all the seal areas are not damaged. sadly oem delco knock sensors are 35-40 bucks each, the harness should be replaced, thats like 22 bucks. then if you have them foam pads that are supposed to seal water out, rtv them in place to make em actually seal water out. and the tq spec matters also. 14 fp. iirc. been a while.
mattbta
Full Access Member
I personally don't trust Amazon for sensors, despite being labeled OE or GM. Lots of fakes and years ago the same item #/sku were dumped in the same warehouse bin regardless of if it were "sold by Amazon" or third party which allowed fakes to get out - not entirely sure if still true, but on things like this I won't risk it.
Logani
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Thanx, Scott and Matt. Good info. Regarding fake "OE" parts on Amazon, the pic for the $35 GM OE 213-3521 sensor is the EXACT photo used on the Summit site. It's hard to know who to trust any more. I'll let you know how it works out....this time.
