High oil pressure after oil change???

Joined
Mar 3, 2005
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Ventura County
Hello everyone. Did a search and haven't found any definitive answers or the same issue I'm having so I'm asking. Just got the oil changed on a fairly new to me (just got this cruiser about 4 months ago) and right after the change, the oil pressure runs at just a hair below the "H" mark. Since I've had it, its always ran in the middle and would fluctuate based upon revs like most cars. Previous owner kept great records and maintained the vehicle (the thing looks practically new, inside and out) so this vehicle has been taken care of. This was the first time changing the oil since I bought it so I'm a bit perplexed with the situation.

Basically here's the situation:

Took the vehicle to the local quick lube (for ease of oil disposal and time)
Provided an OEM toyota oil filter
They drained the oil and changed the filter and filled it with full synthetic oil (using the correct oil weight and amount)
Like typical, they showed me the dip stick reading at the "full line"
All good.


Left the quick lube, got gas next door and then head home about a mile away. It was during my quick drive home that I noticed the oil pressure gauge climbing and eventually topping out at the "H" mark. Pulling in the drive within 5 mins of leaving and immediately checked the oil..... and just like I was shown at the quick lube, it still read at the full mark on the dip stick. Drove straight back to the quick lube (oil gauge still at H) and they looked over the oil lines for kinks and etc.. Nothing kinked so I had them take off the genuine toyota oil filter they just put on and replace it with one of their aftermarket oil filters (my thinking was that maybe by some random chance the toyota oil filter was defective or clogged or who knows what, but that's all I could think would be wrong). Fired the engine up and once again, slowly creeped up to H. Realizing that it's not the oil filter, I left and drove around a bit and the oil pressure stayed at H. Now I'm back home and at a loss at this point.

Once the engine starts, the gauge jumps to the mid way point fairly quickly like normal. However, once there, it slowly starts to creep up to the "H" mark. It does this slowly over about a minute of run time, maybe less, but the point I'm making is that it's not an instantaneous jump to H, it seems to creep up to it from the mid way mark after start up.

Anyway, thoughts, ideas, similar situations? Any help/ advice is appreciated. Thanks

Oh yeah......... 1998 Lexus LX 470, 174,000 miles
 
Joined
Sep 9, 2016
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HAve you tried another oil? They buy bulk oil and can a wrong oil was in the wrong container?

I replaced oil cooler lines so removed the oil filter. I then reinstalled the oil filter and strated the engine. I noticed the oil pressure was bit high than normal but after few minutes, it came back to normal. And I never saw the abnormal rise of the needle thereafter.
 
Joined
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Fort Mill, SC
That's opposite of how it should read. Highest at startup and drops as the engine gets up to temp. I would check the wire at the sensor to see if the "technician" screwed something up while under there.
 
Joined
Mar 3, 2005
Messages
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Location
Ventura County
That's opposite of how it should read. Highest at startup and drops as the engine gets up to temp. I would check the wire at the sensor to see if the "technician" screwed something up while under there.
HAve you tried another oil? They buy bulk oil and can a wrong oil was in the wrong container?

I replaced oil cooler lines so removed the oil filter. I then reinstalled the oil filter and strated the engine. I noticed the oil pressure was bit high than normal but after few minutes, it came back to normal. And I never saw the abnormal rise of the needle thereafter.

Drained their oil and put in mobile full synthetic out of curiosity…. Fired it up and its still the same high pressure.
That's opposite of how it should read. Highest at startup and drops as the engine gets up to temp. I would check the wire at the sensor to see if the "technician" screwed something up while under there.
This sounds about right. Instantly at middle pressure… then slowly goes up to just under H. Almost like something is “hooked” up backwards. Is there an oil sensor close to the oil filter that could of possibly been messed with? Never looked at the oil filter area before but I guess it’s time.

Thanks for responses.
 
Joined
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Messages
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Fort Mill, SC
So the sending unit, as I recall, is a single wire connection. Which seems to imply to me that it's likely getting a variable signal to ground as the pressure increases. I say that because disconnecting it will show 0 , and I believe a direct connection to ground would put it at the top. It's also entirely possible that the sending using has gone bad, and this is just bad timing.
 
Joined
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Odessa/Midland TX
So the sending unit, as I recall, is a single wire connection. Which seems to imply to me that it's likely getting a variable signal to ground as the pressure increases. I say that because disconnecting it will show 0 , and I believe a direct connection to ground would put it at the top. It's also entirely possible that the sending using has gone bad, and this is just bad timing.
Oil pressure sender is directly attached to the oil filter unit. It's easy to remove and replace, ise a 10 mm and unscrew it and then install the new unit. USE oem and this part should not be expensive. See what ^^ said, remove the wire plug and sensor should show nothng and once fully grounded the gauge should move to H. There is only once I have to deal with the pressure guage and it is on the hilux. Needle didn't respond and a new OEM unit made the correction.

You can observe the opening on the pressure sender. There is one opening in the middle and it is an oil channel. Look for any debris. sometimes those shops prefill the filter and mount it. This is a bad practice as a dirt getting in the the moddle of the filter will be pulled right into the engine.
 
Joined
Mar 3, 2005
Messages
148
Location
Ventura County
Oil pressure sender is directly attached to the oil filter unit. It's easy to remove and replace, ise a 10 mm and unscrew it and then install the new unit. USE oem and this part should not be expensive. See what ^^ said, remove the wire plug and sensor should show nothng and once fully grounded the gauge should move to H. There is only once I have to deal with the pressure guage and it is on the hilux. Needle didn't respond and a new OEM unit made the correction.

You can observe the opening on the pressure sender. There is one opening in the middle and it is an oil channel. Look for any debris. sometimes those shops prefill the filter and mount it. This is a bad practice as a dirt getting in the the moddle of the filter will be pulled right into the engine.
Thank you so much! Now it’s starting to make sense. I kept wondering how the hell those guys could have touched anything to mess with the oil sending unit, but now it makes total sense. Otherwise I was just assuming that my unit coincidentally went bad just as I had the oil changed (still a possibility, but at least I have a better understanding of things). Guess I’ll be getting acquainted with the oil filter area a lot sooner. Thanks to all of you guys for chiming in!
 
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Baton Rouge, LA
Thank you so much! Now it’s starting to make sense. I kept wondering how the hell those guys could have touched anything to mess with the oil sending unit, but now it makes total sense. Otherwise I was just assuming that my unit coincidentally went bad just as I had the oil changed (still a possibility, but at least I have a better understanding of things). Guess I’ll be getting acquainted with the oil filter area a lot sooner. Thanks to all of you guys for chiming in!

There's not much to it, if you have the factory metal skid plate, there might be a small oval cover that needs to be removed to see the oil filter and sending unit.
 
Joined
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Oil sending unit might not be able to access through the small window. Time to remove the front skid plate. It is heavy so be prepared to hold it.

I never been to a quick lube and never will. Same goes for repairs... All by my self! I learned to wrench by messing with my dad's British made Ford Cortina!
 

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