2001 cherokee sport, low oil pressure at warm idle
#1
Newbie
Thread Starter
Join Date: Dec 2018
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee (XJ)
2001 cherokee sport, low oil pressure at warm idle
I have a 2001 cherokee sport. A couple years back my engine overheated. Following this, I replaced the cooling system with a brand new radiator, thermostat, and hoses. I noticed my oil pressure slowly began to drop to zero when the engine was at running temp while idling. For a short time it didn't seem to drop completely to zero, but eventually it began dropping completely to zero at warm idle, but would rise when I accelerated. I never noticed any loud knocking while this would happen, but still worried about possible damage. In order to prevent damage I would lightly throttle it while holding the brake while stopped at a red light, this way I was able to prevent psi dropping to zero and the "check gauges" light from turning on. First I tried a thicker 50w oil, this defiantly delayed the time and speed for the oil pressure to drop to zero, it wouldn't drop as fast when stopped and took more time after starting the engine for the low pressure problem to begin, but eventually it would still drop to zero at idle, especially on hot days. Next we replaced the sending unit, no luck. Then the oil pump was replaced, no luck. Then After learning about the "0331 Tuppy Head cracking issue", I removed the oil cap and looked down into the top of the engine to discover it was in fact cracked, between cylinders 3 and 4. So I replaced the cracked head with a brand new head I purchased from odessa cylinder(formerly clearwater cylinder), to end up with the same "oil pressure dropping to zero at warm idle" problem. Now recently we began checking bearing clearances, so far all connecting rod bearing clearances are within allowable spec range, clearance on connecting rod bearings 1-6 =(0.002"-0.00175"). Regarding the main bearings(MainBear-1=0.0175") (MB-2=0.0016") (MB-3=0.0015")(MB-4=0.0015")(MB-5=0.0019")(MB-6=0.00175"). So now what?! This is about to send me to the psych tank....Again!!! What else could it be?
#2
CF Veteran
Has the oil pressure ever been verified with a mechanical gauge? If not I'd give it try.
https://www.harborfreight.com/engine...kit-62621.html
https://www.harborfreight.com/engine...kit-62621.html
#3
May be too simple of an answer but when you replaced the oil pressure sending unit did you clean out the port with a pipe cleaner? Gunk can build up in there and give a bad reading also you may want to swap that sensor again with known working one depending on the brand you used.
Thread
Thread Starter
Forum
Replies
Last Post
nitrousjunky
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
23
01-17-2019 06:04 AM
derick195
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
12
06-30-2017 05:46 PM
resqman911
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
13
11-09-2012 04:18 PM
CrawlerXJ
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
19
06-27-2012 07:10 PM
plated
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
1
10-23-2011 01:55 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)