Low Oil Pressure Fix
joeyd13903
07-09-2005, 09:41 PM
When I first posted on this forum it was in regards to the low oil pressure on my S-10. I received some great advice regarding the oil and the oil sending unit. Thanks to rlith and OverBoardProject - you guys are great!
So, I thought I'd post my experiences today replacing the sending unit for others like me that aren't experienced in the process. I don't know if the information following has been offered in other threads, but for the sake of the posters/visitors here I thought it'd be helpful for those that are having problems with it.
IF you are having problems getting the oil sending unit off (mine is an '88 Blazer, 4.3L tbi) I have read several posts that suggest using an open end wrench to get it off, and some have just suggested crossing your fingers and doing the best you can.
NAPA carries extra deep sockets that fit perfectly over the sending unit - different sizes for different years, units, etc....My old unit needed a larger one and the new unit a smaller one, etc...Total they were $30 combined. Not bad considering I had no idea how I was going to get the thing off without a socket.
OK, so I go to remove the old oil sending unit and get the socket (after removing the crap that has to be removed to get to the darned thing) on and start removing the old sending unit. SNAP! goes the 22 degree offset coupler/union that holds it to the block - at the block. Nice.
I used an "easy out" broken bolt/screw remover to get the remainder of the fitting out - thank God it was brass and the easy out bit quite, well, easily.
When I went to NAPA, the local Chevy dealer and a few other stores to buy the new fitting I found out that nobody around here carries it, so I went to Home Depot and bought a 1/8" thread coupler, a 1 " nipple and a 90 degree coupler.
I put the 1" nipple and the 90 degree offset together first and screwed them onto the block. I then put the coupler on the actual sending unit, then screwed that into the offset (90 degree). This made it very easy to get it on, despite the fact that it now runs 90 degrees away from the engine block and behind the bracket that holds the throttle cable. Then I just tightened the coupler with a wrench and put the bracket ,cables and the air cleaner assembly back on and started her up. The added benefit is that if I have to replace it again I can just loosen the coupler and remove it there without torquing the fitting at the block or the sending unit. The downside is that I now own two sockets that I no longer need.
The oil pressure gauge immediately read over 40, which it hasn't done since I got the truck. I let it warm up for about ten minutes, checking the area around the sending unit and the ground for any leaks, which thankfully there weren't any.
After driving the truck for about 30 minutes to get it good and warm, when the "check gauges" light usually begins its appearances and the gauge drops down to about 5 at stops the pressure NEVER dropped below 40, in fact it stayed up around 50 most of the time. It ran much better overall. (While I was at it I also changed the pcv and egr valves.)
The purpose for this thread is for those like me that are admittedly NOT mechanics. It's a pain in the butt but not as bad as I thought it would be.
I hope this helps anyone with the same problem!
So, I thought I'd post my experiences today replacing the sending unit for others like me that aren't experienced in the process. I don't know if the information following has been offered in other threads, but for the sake of the posters/visitors here I thought it'd be helpful for those that are having problems with it.
IF you are having problems getting the oil sending unit off (mine is an '88 Blazer, 4.3L tbi) I have read several posts that suggest using an open end wrench to get it off, and some have just suggested crossing your fingers and doing the best you can.
NAPA carries extra deep sockets that fit perfectly over the sending unit - different sizes for different years, units, etc....My old unit needed a larger one and the new unit a smaller one, etc...Total they were $30 combined. Not bad considering I had no idea how I was going to get the thing off without a socket.
OK, so I go to remove the old oil sending unit and get the socket (after removing the crap that has to be removed to get to the darned thing) on and start removing the old sending unit. SNAP! goes the 22 degree offset coupler/union that holds it to the block - at the block. Nice.
I used an "easy out" broken bolt/screw remover to get the remainder of the fitting out - thank God it was brass and the easy out bit quite, well, easily.
When I went to NAPA, the local Chevy dealer and a few other stores to buy the new fitting I found out that nobody around here carries it, so I went to Home Depot and bought a 1/8" thread coupler, a 1 " nipple and a 90 degree coupler.
I put the 1" nipple and the 90 degree offset together first and screwed them onto the block. I then put the coupler on the actual sending unit, then screwed that into the offset (90 degree). This made it very easy to get it on, despite the fact that it now runs 90 degrees away from the engine block and behind the bracket that holds the throttle cable. Then I just tightened the coupler with a wrench and put the bracket ,cables and the air cleaner assembly back on and started her up. The added benefit is that if I have to replace it again I can just loosen the coupler and remove it there without torquing the fitting at the block or the sending unit. The downside is that I now own two sockets that I no longer need.
The oil pressure gauge immediately read over 40, which it hasn't done since I got the truck. I let it warm up for about ten minutes, checking the area around the sending unit and the ground for any leaks, which thankfully there weren't any.
After driving the truck for about 30 minutes to get it good and warm, when the "check gauges" light usually begins its appearances and the gauge drops down to about 5 at stops the pressure NEVER dropped below 40, in fact it stayed up around 50 most of the time. It ran much better overall. (While I was at it I also changed the pcv and egr valves.)
The purpose for this thread is for those like me that are admittedly NOT mechanics. It's a pain in the butt but not as bad as I thought it would be.
I hope this helps anyone with the same problem!
BlazerLT
07-10-2005, 02:08 PM
Nice work.
'89sdimeblazer
07-11-2005, 12:14 PM
did ur truck run really rough when you came to a stop and it kicked down to low idle??? cuz i belive my sending unit is bad. when i start it cold it runs at 40 then i drive it and it slowly goes down and when i stop it runs real ratty then when i go it barely breaks 30. i was wonder how much the unit costs if u could reply that would be great thanks.
-ricky
-ricky
joeyd13903
07-11-2005, 09:08 PM
did ur truck run really rough when you came to a stop and it kicked down to low idle??? cuz i belive my sending unit is bad. when i start it cold it runs at 40 then i drive it and it slowly goes down and when i stop it runs real ratty then when i go it barely breaks 30. i was wonder how much the unit costs if u could reply that would be great thanks.
-ricky
It did run rough at idle and the oil pressure would drop to around 5-10. The sending unit was less than 20 bucks. Check how many wires are coming out the top of the unit - if there's 3 it's a 1/4 thread, if 2 it's a 1/8" thread or something - whichever unit is smaller. They both cost the same.
Good luck!
JD
-ricky
It did run rough at idle and the oil pressure would drop to around 5-10. The sending unit was less than 20 bucks. Check how many wires are coming out the top of the unit - if there's 3 it's a 1/4 thread, if 2 it's a 1/8" thread or something - whichever unit is smaller. They both cost the same.
Good luck!
JD
'89sdimeblazer
07-12-2005, 05:53 PM
hey thanks... one more question did u have n e problem getting the sensor off the top of the sending unit. i took a peek today and just for shits tried to take the sensor out but it was on there and im not sure how to go about getting it out i went to auto zone today to verify which one i have its the 1/8 inch with 3 wires well try to get back to me on that one thank you
joeyd13903
07-13-2005, 09:33 PM
hey thanks... one more question did u have n e problem getting the sensor off the top of the sending unit. i took a peek today and just for shits tried to take the sensor out but it was on there and im not sure how to go about getting it out i went to auto zone today to verify which one i have its the 1/8 inch with 3 wires well try to get back to me on that one thank you
As I said in the first post it can be a pain in the butt. I bought the socket specially made for the sensor at NAPA. I actually had to buy two because the old sending unit was larger than the new one. I had to remove the air cleaner assembly and the bracket that holds the throttle, ect...cables. Once those are out of the way it's not too hard to get to, but don't torque the snot out of the thing or it will break off at the brass fitting that holds it to the block. Then you have to do what I had to do and use an easy out to get the rest of the fitting out...NOT a fun time.
Anyway...good luck!
As I said in the first post it can be a pain in the butt. I bought the socket specially made for the sensor at NAPA. I actually had to buy two because the old sending unit was larger than the new one. I had to remove the air cleaner assembly and the bracket that holds the throttle, ect...cables. Once those are out of the way it's not too hard to get to, but don't torque the snot out of the thing or it will break off at the brass fitting that holds it to the block. Then you have to do what I had to do and use an easy out to get the rest of the fitting out...NOT a fun time.
Anyway...good luck!
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