Replacing the Oil Pressure Sending Unit
11-14-2016, 11:05 PM
#1
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Join Date: 04-09-2006
Location: Vancouver, BC, Canada
Posts: 7,032
Replacing the Oil Pressure Sending Unit
My 2.4L had a pretty bad oil leak down the front of the engine (2.4L) just below the Oil filter housing which was traced to the Oil Pressure Sending unit, which is screwed into the front of the block.
Replacing the sending unit requires the starter motor be removed, as it is not accessible from the top side (at least not with any of the tools I have available).
The process to replace it was as follows:
PREP WORK:
- disconnect the NEGATIVE post on the battery
- manually flip the latch inside the bottom of the hatch to the closed position so you don't lock yourself out of the trunk - OR, throw a piece of carpet over the latch point
- jack up the drivers front side of the vehicle and block it securely
REMOVE STARTER MOTOR:
- using a 8mm wrench remove the small nut on the end of the starter (I believe it is the trigger wire for the solenoid), and remove the wire
- remove the power lead nut (it will probably be 12 or 13mm depending on the specific starter), and remove the two wires from the bolt, and push them aside
- there are two bolts holding the starter in place, one that is at the bottom, and one on top but totally hidden. I believe they are 14mm, so use a ratchet and an extension to remove them both
- pull the starter free of the block and place it aside (no shims were noted between it and the block in my case, but keep an eye out for them in case)
RE and RE OIL PRESSURE SENDING UNIT
the sending unit's nut on the base is 27mm if I remember right, but the only one I had was not a deep socket, and I didn't have a 27mm wrench handy, and there is limited room to play with..... soooooo....
- disconnect the connector from the oil pressure sending unit
- disconnect the black connector from what I believe is the crankshaft position sensor (lift the red tab to enable removal)
- use a 14mm wrench/socket to remove the bolt that holds the anti-knock sensor against the block (located just below the oil sending unit)
- remove the oil pressure sending unit with a suitable tool (I used a crescent wrench - ok.... shame on me, but it was all I had) - be prepared for some oil to leak out of the hole that it comes out of
- install the new oil pressure switch - 16 lb ft and attach it's connector
- reinstall the anti-knock sensor and it's bolt - 18 lb ft
- reattach the connector for the anti-knock sensor, and push the red tab in to lock it in position
REINSTALL STARTER:
installation is just the reverse of the removal -
- install the starter with the two bolts (14mm socket) - 39 lb ft
(do the top bolt first loosely as it seems easier to get it located as it is done all blind)
- place the two big power leads on the stud, and lock them in place with the 13/14 mm nut - not sure of the torque on this - just be careful not to strip the stud as it is not exactly heavy duty
- place the solenoid driver wire in place on the small stud and tighten it in place with the small 8mm nut
FINISH
- reattach the negative battery post in the trunk
- use the fob or turn on the ignition key and use the touch pad on the hatch to unlock - it will flip the lock in the bottom of the hatch to the open position - the hatch can now be safely closed
- lower the car back to the ground
- start the engine and look for any leaks
- reset the time on the radio
Replacing the sending unit requires the starter motor be removed, as it is not accessible from the top side (at least not with any of the tools I have available).
The process to replace it was as follows:
PREP WORK:
- disconnect the NEGATIVE post on the battery
- manually flip the latch inside the bottom of the hatch to the closed position so you don't lock yourself out of the trunk - OR, throw a piece of carpet over the latch point
- jack up the drivers front side of the vehicle and block it securely
REMOVE STARTER MOTOR:
- using a 8mm wrench remove the small nut on the end of the starter (I believe it is the trigger wire for the solenoid), and remove the wire
- remove the power lead nut (it will probably be 12 or 13mm depending on the specific starter), and remove the two wires from the bolt, and push them aside
- there are two bolts holding the starter in place, one that is at the bottom, and one on top but totally hidden. I believe they are 14mm, so use a ratchet and an extension to remove them both
- pull the starter free of the block and place it aside (no shims were noted between it and the block in my case, but keep an eye out for them in case)
RE and RE OIL PRESSURE SENDING UNIT
the sending unit's nut on the base is 27mm if I remember right, but the only one I had was not a deep socket, and I didn't have a 27mm wrench handy, and there is limited room to play with..... soooooo....
- disconnect the connector from the oil pressure sending unit
- disconnect the black connector from what I believe is the crankshaft position sensor (lift the red tab to enable removal)
- use a 14mm wrench/socket to remove the bolt that holds the anti-knock sensor against the block (located just below the oil sending unit)
- remove the oil pressure sending unit with a suitable tool (I used a crescent wrench - ok.... shame on me, but it was all I had) - be prepared for some oil to leak out of the hole that it comes out of
- install the new oil pressure switch - 16 lb ft and attach it's connector
- reinstall the anti-knock sensor and it's bolt - 18 lb ft
- reattach the connector for the anti-knock sensor, and push the red tab in to lock it in position
REINSTALL STARTER:
installation is just the reverse of the removal -
- install the starter with the two bolts (14mm socket) - 39 lb ft
(do the top bolt first loosely as it seems easier to get it located as it is done all blind)
- place the two big power leads on the stud, and lock them in place with the 13/14 mm nut - not sure of the torque on this - just be careful not to strip the stud as it is not exactly heavy duty
- place the solenoid driver wire in place on the small stud and tighten it in place with the small 8mm nut
FINISH
- reattach the negative battery post in the trunk
- use the fob or turn on the ignition key and use the touch pad on the hatch to unlock - it will flip the lock in the bottom of the hatch to the open position - the hatch can now be safely closed
- lower the car back to the ground
- start the engine and look for any leaks
- reset the time on the radio
Last edited by whopper; 03-16-2017 at 10:27 AM.
11-30-2016, 04:03 PM
#8
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Join Date: 10-13-2011
Location: Welland,Ont Canada
Posts: 36,498
I did this today, the knock sensor had a 10 mm bolt holding it
The starter mounting bolts were 15 mm
The battery cable to the starter nut was a 13mm
That top bolt was a treat to get into position, the oil pressure switch was only finger tight , and leaking where the plastic body meets the metal nut piece that threads into the block.
Thanks again for the write up, it was starting to sprinkle rain so I did not take pictures either.
The starter mounting bolts were 15 mm
The battery cable to the starter nut was a 13mm
That top bolt was a treat to get into position, the oil pressure switch was only finger tight , and leaking where the plastic body meets the metal nut piece that threads into the block.
Thanks again for the write up, it was starting to sprinkle rain so I did not take pictures either.
12-29-2016, 10:16 AM
#9
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Join Date: 10-13-2011
Location: Welland,Ont Canada
Posts: 36,498
Okie, dokie, a month, almost and 2,000 Kim's or 1,245 miles there abouts and no pesky oil loss, no drips on the oil or transmission pans, I can back into my sloped driveway and park nose down , no oil drops on the driveway! Yeah, it's like I have my HHR back!!
Next is Sweetie's GT!! It sits level in the garage , no drops, if I dare park it nose down outside over the course of an afternoon, a small drip or two!
And I always thought the leak was spillage from changing the oil filter!
Next is Sweetie's GT!! It sits level in the garage , no drops, if I dare park it nose down outside over the course of an afternoon, a small drip or two!
And I always thought the leak was spillage from changing the oil filter!
Last edited by Oldblue; 12-21-2019 at 04:08 PM.
12-29-2016, 08:46 PM
#10
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Thread Starter
Join Date: 04-09-2006
Location: Vancouver, BC, Canada
Posts: 7,032
Cool - mine was leaking the same way (an internal leak, not from where it screws into the block). So far so good with mine as well. My old starter had a 12mm nut on the power connection, and the new one was 13mm I believe.