Another Seafoam thread
02-18-2020, 05:25 PM
#16
CF Veteran
I will get that on occasion with mine...but doesn't do it all the time...sounds just like a little lifter tick.
02-18-2020, 05:27 PM
#18
Old fart with a wrench
There are 2 things making noise under there. One is the leak detection pump IF your jeep has one, and the other is the canister purge solenoid. On cold startup, the leak detection pump pressurizes the evap system and rates how long it takes for the system to leak down. If it's too fast, it will set a CEL for an evap leak. The canister purge solenoid cycles to draw captured vapors in the carbon canister out, allowing them to be burned in the engine. That will cycle as long as the engine is running.
02-18-2020, 05:29 PM
#19
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Year: 1995 RHD
Model: Cherokee (XJ)
Engine: 4.0l
There are 2 things making noise under there. One is the leak detection pump IF your jeep has one, and the other is the canister purge solenoid. On cold startup, the leak detection pump pressurizes the evap system and rates how long it takes for the system to leak down. If it too fast, it will set a CEL for an evap leak. The canister purge solenoid cycles to draw captured vapors in the carbon canister out, allowing them to be burned in the engine. That will cycle as long as the engine is running.
I did poke around and couldn't see anything last week.
02-18-2020, 05:41 PM
#20
Old fart with a wrench
IDK for sure, but I've been told some XJs don't have a leak detection pump, only the canister purge solenoid. The purge solenoid is right in front of the heater blower motor in the engine compartment on a LHD model. The pump would probably be directly underneath it. I'll check with my 2000 FSM.....
According to my FSM, the LDP is only used on "certain emission packages." Whatever that means. The canister is under the floor in front of the rear axle.
According to my FSM, the LDP is only used on "certain emission packages." Whatever that means. The canister is under the floor in front of the rear axle.
Last edited by dave1123; 02-18-2020 at 05:57 PM.
02-18-2020, 05:48 PM
#21
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
02-18-2020, 08:10 PM
#22
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02-18-2020, 10:36 PM
#24
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
02-18-2020, 10:42 PM
#25
CF Veteran
Oh so it's cool to have that extra volume in there of the MMO along with the normal oil level already?? Because I've already got my T6 level just a tick above the full mark on the stick right now.
Last edited by RocketMouse; 02-18-2020 at 10:45 PM.
02-18-2020, 10:52 PM
#26
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
02-18-2020, 11:33 PM
#27
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02-19-2020, 12:47 PM
#28
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Year: 1995 RHD
Model: Cherokee (XJ)
Engine: 4.0l
I've got it ordered and should have it by Friday with any luck.
02-19-2020, 04:51 PM
#29
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Year: '96
Model: Cherokee (XJ)
Engine: 4.0 HO
There are 2 things making noise under there. One is the leak detection pump IF your jeep has one, and the other is the canister purge solenoid. On cold startup, the leak detection pump pressurizes the evap system and rates how long it takes for the system to leak down. If it's too fast, it will set a CEL for an evap leak. The canister purge solenoid cycles to draw captured vapors in the carbon canister out, allowing them to be burned in the engine. That will cycle as long as the engine is running.
Can you take a 10 second video of the sound to post up...???
02-19-2020, 05:22 PM
#30
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Year: 1995 RHD
Model: Cherokee (XJ)
Engine: 4.0l
As you asked so kindly. I actually recorded this and forgot about it on the 12th, I'm not sure if this was when it was louder or quieter after.