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Oil pressure light

lowtrac

Well-Known Member
Messages
222
Location
Georgia
I've read a bunch of stuff on this, but wanted to see if there was any new wisdom.

2006 H3. I've had the issue before where you drive for a while (like on the highway) and when you exit and stop you get the oil light. I swapped out the oil pressure sender almost a year ago and that problem went away. Recently I've started getting the light coming on at random times, not just while coming to a stop. I changed the oil this past weekend and it's still doing it. I'm using Valvoline high mileage 5w30 and a PurolatorONE filter. Do you think the sender may be bad again? The replacement I used was an ACDelco. I've read about maybe going with a higher weight oil as well. Any thoughts on this? Everything else seems normal. No new noises, temp is good, etc.
 

amrg

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2,317
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Qatar
If you already changed the sensor, have you changed the oil and filter?
If yes try an engine oil flush, if lt doesnt work, try seafoam
I had a similar issue, whenever oil would get hot enough the light comes on. Had the Engine out and opened and turned out there is a small bypass valve inside it that is clogged. Its job was to let oil bypass something when its cold and once the engine oil was hot it wasnt doing its job anymore.

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lowtrac

Well-Known Member
Messages
222
Location
Georgia
I went ahead and ordered a new sensor this morning.

I did just change the oil and filter three days ago. I'm familiar with seafoam, but have never used it.
 

EndeavoredH3

Well-Known Member
Messages
371
Location
Arizona
I used sea foam on my last oil change and it reduced some valve train noise. Thought that perhaps the hydraulic lifters were a little gunked up and they were. When I drained the oil after running the motor with the sea foam for a while there was noticible amount of carbon deposits and stuff that were on the bottom of my drain pan. Currently have 160,000 miles on the motor.

Also, I’ve been running full synthetic for the past few months and that is a decent cleaner in itself. I would try sea foam and see if that helps the valve that amrg is talking about.
 

rascole

Well-Known Member
Messages
2,580
Location
Bellflower, CA
Before you spend money on products, first find out what your oil pressure is. If it is low then no off the shelf product is going to fix it (except a bad-aid fix using higher wieght oil).
There is a plug located next to the sending unit that you can plumb up a pressure gauge to. I don't know the thread size, or you can use the sending unit tap.
 

amrg

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I used full synthetic since day one and did oil change every 6K but the oil always turned very dark. Those engines seem to run hot oil wise.

I forgot to add, check the oil pickup screen, some gunk on it can easily block it and give pressure issues.

Btw with the engine out and opened, the bearings where still in great condition and so was the oil pump (was expecting to rebuild it)

Gd luck
 

lowtrac

Well-Known Member
Messages
222
Location
Georgia
Before you spend money on products, first find out what your oil pressure is. If it is low then no off the shelf product is going to fix it (except a bad-aid fix using higher wieght oil).
There is a plug located next to the sending unit that you can plumb up a pressure gauge to. I don't know the thread size, or you can use the sending unit tap.

I want to figure this out too. I see references to it, but I haven't seen where someone was actually able to accomplish installing a mechanical gauge. I'll report back what I find.
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
I had the same issue and for some reason the second sensor, one year later, resolved the issue. Haven't had the light come back on.
 

gamma195

Member
Messages
17
Location
WA
I case you want to do the oil pressure gauge installed, I just did mine this winter. Not sure if my new status (low posts) on this forum will allow me to post links yet, but Ill post the descriptions.

Its not that hard to install an oil pressure gauge in the H3 I5, easier than I thought it would actually. There is a plug (with a torx or allen head) just above the oil filter on the front of the engine. That plug is threaded and it it is in the oil pressure channel. You just need a gauge and adapter. I got mine on Amazon

1. Plug: LS Engine Swap M16 1.5 Adapter to 1/8 NPT Oil Pressure Sensor LS1 LSX LS3 Gauge 551172

https://www.amazon.com/gp/product/B015NFNC10/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

2. Gauge. You can use what you want, but this worked for me.
GlowShift Tinted 7 Color 100 PSI Oil Pressure Gauge Kit - Includes Electronic Sensor - Black Dial - Smoked Lens - For Car & Truck - 2-1/16" 52mm

https://www.amazon.com/gp/product/B007GE2SIA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

3. A holder that fits the gauge.

All you have to do is remove the plug, install the adapter (with a little silicone), screw in the sensor that comes with the gauge into the adapter, route your wires, add power, and profit.

Its been working well for me for about 6 months. This picture is from another forum (so whoever made it you get credit) The sensor with the blue coiled wire is an aftermarket oil pressure sensor. the torx bolt is where the brass 90 degree elbow is. You do not need the elbow if you use the gauge i linked, its sits low enough in that it doesnt rub against anything.

capture_e5b009de22f729fa865a350bace936380f918f9a (1).png
 
Last edited:

lowtrac

Well-Known Member
Messages
222
Location
Georgia
I had the same issue and for some reason the second sensor, one year later, resolved the issue. Haven't had the light come back on.

The new sensor came in yesterday, but I haven’t had the light come on since Wednesday morning. I’m going to hold off on replacing it for now. We’ll see how it goes.


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lowtrac

Well-Known Member
Messages
222
Location
Georgia
I case you want to do the oil pressure gauge installed, I just did mine this winter. Not sure if my new status (low posts) on this forum will allow me to post links yet, but Ill post the descriptions.

Its not that hard to install an oil pressure gauge in the H3 I5, easier than I thought it would actually. There is a plug (with a torx or allen head) just above the oil filter on the front of the engine. That plug is threaded and it it is in the oil pressure channel. You just need a gauge and adapter. I got mine on Amazon

1. Plug: LS Engine Swap M16 1.5 Adapter to 1/8 NPT Oil Pressure Sensor LS1 LSX LS3 Gauge 551172

https://www.amazon.com/gp/product/B015NFNC10/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

2. Gauge. You can use what you want, but this worked for me.
GlowShift Tinted 7 Color 100 PSI Oil Pressure Gauge Kit - Includes Electronic Sensor - Black Dial - Smoked Lens - For Car & Truck - 2-1/16" 52mm

https://www.amazon.com/gp/product/B007GE2SIA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

3. A holder that fits the gauge.

All you have to do is remove the plug, install the adapter (with a little silicone), screw in the sensor that comes with the gauge into the adapter, route your wires, add power, and profit.

Its been working well for me for about 6 months. This picture is from another forum (so whoever made it you get credit) The sensor with the blue coiled wire is an aftermarket oil pressure sensor. the torx bolt is where the brass 90 degree elbow is. You do not need the elbow if you use the gauge i linked, its sits low enough in that it doesnt rub against anything.

View attachment 24160

This is great info. I appreciate you sharing it.

I’ll definitely do that if/when the issue comes up again.


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lowtrac

Well-Known Member
Messages
222
Location
Georgia
So, after the light had been off for a few days it started to get really ornery. I parked the H3 for a few days until I had time to swap the sensor.

I think the issue is that I’ve got a power steering fluid leak at the back of the pump which is dripping fluid on the sensor. I swapped it out and cleaned everything up and it’s been good to go for almost a week so far. I bought a new pump a while back and never installed it. I guess it’s about time. The wiring at the plug for the sensor is pretty ratty too. I’d like to replace the plug and wiring. Has anyone found one? I haven’t looked yet, but it’s not a normal looking plug so I figure it’ll be hard to find.


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lowtrac

Well-Known Member
Messages
222
Location
Georgia
She’s still complaining.

I did find a new plug. AC Delco part # 13585859. It came with a couple of butt splices and about a foot of wire.

6c192fae80dddc6e864462e41ed80e1f.jpg


I’ll get it put in this week sometime. I also noticed this morning what I believe to be the wiring going to the plug. It’s mostly out of its plastic wire loom thing and lying across the exhaust heat shield. Can anyone confirm that’s the way the wire runs? If the insulation is rubbed through/melted then it would be randomly shorting against the heat shield which would be an issue I imagine.


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alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
She’s still complaining.

I’ll get it put in this week sometime. I also noticed this morning what I believe to be the wiring going to the plug. It’s mostly out of its plastic wire loom thing and lying across the exhaust heat shield. Can anyone confirm that’s the way the wire runs? If the insulation is rubbed through/melted then it would be randomly shorting against the heat shield which would be an issue I imagine.

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Sounds like a bit of new loom and a zip tie may be your solution.
 

lowtrac

Well-Known Member
Messages
222
Location
Georgia
I definitely like the idea of adding an oil pressure gauge. The references for those parts will help.

I agree. I’m going to replace the plug and some wiring and see what happens first. I’ll go with a gauge after that if necessary.


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gamma195

Member
Messages
17
Location
WA
Just another thought with those with older/high mileage engines. My oil light came on as well. I changed the sensor, flushed the motor about 5 times, switched to rotella to continue cleaning. Yet, the oil light would still come on. Especially after long drives coming off the freeway to a stop. So the oil is getting hot and thin. These motors don't have the best oil pressure tolerance and due to wear or a cracked ring can lose pressure quickly.

If your vehicle is like mine, you have a few options: 1) fix the problem (i.e. rebuild or rering) or since that sucks, get a pressure gauge like I said above and see what the motor is doing. If you are maintaining constant but lower pressure at idle then you can: 1) add thicker oil (start with 5w40 to start, rotella T6 fits this bill and it cleans!) and/or have your idle bumped up as an ECU tune. I ended up doing option two. I found the idle to be too low anyways from the factory (650 RPM I believe). I had them bump it to 685-700. Oil light now does not come on at idle. Why is this? A slightly higher idle adds more oil pressure. I did mine through PCMforless (which provides other performance benefits at the same time). This also makes the idle much more smooth. Just make sure to tell them in the notes section what you want or call them direct.

I have 10,000 miles on the engine since I did this (now has 220,000) and hasn't come on since.
 

lowtrac

Well-Known Member
Messages
222
Location
Georgia
I’m sure this was my problem. The bare portions of the wiring were against the heat shield. New plug/wiring/loom and some zip ties are in.

fb196c660f41e405461377d06bc97cbd.jpg


I’ll be able to drive it for a while tomorrow to make sure.


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JPaul

Well-Known Member
Messages
2,400
Location
Way up north, UT
Maybe get some of the reflective heat sleeving to put over it if it's right by the exhaust to help prevent that from happening again down the road.
 
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