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First 32* Day of the Year - Oil Pressure Drops to Zero

beasticles

NAXJA Forum User
Location
Northern VA
Fellas - Quick question. I have had my 2001 Jeep XJ (4.0) since March and in that time have fixed the leaking oil from the RMS, valve cover, and oil filter adapter, along with too many other things to count.

When I replaced the RMS I of course put on a new oil pan gasket. For about the last 3 weeks the front of the pan has developed a slow leak where I applied RTV to the bell housing area (this is just below the pulley - the lowest point on the oil pan). Not a huge leak, a drip or two every 24-48 hours.

I have driven the Jeep for the last several weeks off and on (it's not a DD) including a 300 mile round trip to the mountains and back. I have driven the Jeep the last three days where temps were above 40* and have had no issues.

This morning I drove the Jeep to work and temps were in the low 30* temps. Once the engine heated up, at stops, the oil pressure dummy gauge on the dash dropped to zero and the "check gauges" light came on.

What is the most likely culprit of this given the fact it has been running fine up until this cold day? A couple ideas based on reading this morning are below:

>Fix the oil leak by dropping oil pan and replacing gasket? Could that be causing the problem? Seems to have been running fine otherwise.
>While I was down there I would replace the oil pump.
>Replace the oil pressure sending unit (may try this first since it is easy)
>Clean electrical connectors on oil sending unit which have likely built up sludge over the years (might try this first since it is easy)
>Replace FRAM oil filter with a WIX or NAPA Gold filter
>Worst case there has been mention of the 0331 head crack but I have not been losing coolant and the oil level seems fine
 
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Unless you want to deal with fixing the leak in cold weather, id start by replacing the oil pressure sending unit with a new, good quality one from the dealer or NAPA and see if that changes anything and go from there...

Oops... I just saw that on your post... But still, I've seen a lot of issues with cheap replacements, get a quality one and be done...
 
Unless you want to deal with fixing the leak in cold weather, id start by replacing the oil pressure sending unit with a new, good quality one from the dealer or NAPA and see if that changes anything and go from there...

Oops... I just saw that on your post... But still, I've seen a lot of issues with cheap replacements, get a quality one and be done...

Thanks for your post. That'll be the first place I stop. All signs point to that so knock on wood that's all this is. The engine continued to run just fine after the gauge dropped to zero so I am hoping it's just a faulty sender.
 
For what its worth, a NAPA Echlin oil pressure sensor worked great on my 01 XJ.

On my 97 XJ the NAPA Echlin sensor (different wiring/part) do not read the same as the dealer. On the 2nd one which will also be returned for refund.

NAPA has 30% off until the 16th if it fits in a 5 gallon pail. You do need to buy the pail for $3.
 
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