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Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
Knocking noise and gasoline smell in cabin after cold start, as engine warms up, and when hot. Gasoline smell disappears after a little while.
MIL/engine light was on with codes P0455 (MIL-Code 31) and P1687, but the light has since turned off. Vehicle is slow to accelerate on the road.
Following has been going on for a while.
There is also a whirring type noise when it starts up and changes in pitch as RPM climbs. Sometimes it disappears.
Loud rumbling when idle when engine is hot after coming to a stop. Sounds like it comes from behind the passenger seat, but not sure.
Have had replaced: Spark plugs, gas cap, valve cover gasket, brake drums.
Oil level is fine.
Was that video made during a cold idle right after starting the vehicle? Or was the engine up to operating temperature?
The loud rumble at idle is likely your exhaust system rumbling on your cross member due to a worn out transmission mount and motor mounts. The amount of room between the exhaust pipe and the cross member is very small, so it doesn't take much. If this is the cause, it is not an expensive fix, and there are plenty of vids and write ups about it.
The transmission mount can definitely be done by a layman. It is just easy nuts and bolts. You do need a good floor jack or bottle jack to support the transmission/transfer case while you remove the cross member (the big metal frame support that connects at each frame rail). I've done it a few times, and can now do it from start to finish in about 12 minutes (not kidding). The first time was maybe an hour, because I was timid.
The motor mounts are a bit more involved, but not technically difficult. You can find videos on youtube to show you.
Start with a Mopar transmission mount (don't buy a cheap after market one, unless you want to do the job again in the next few days AFTER buying a Mopar mount).
You can always do the motor mounts after you have taken a look to see what type of shape they are in. Its the transmission mount that really provides the exhaust clearance over the cross member.
Before doing anything, why don't you get under there while it is idling and just inspect whether the exhaust is contacting the cross member while idling. It is right under the center passenger side of the vehicle. Have a helper put their foot on the brake, put it in gear, and give it just a small rev up a few times to be thorough (as the engine torques, it can change the exhaust position even more).
gasoline smell: check carefully the injector and the seats.... don't use a lighter... if you do, make a video.... if it's just an oring, they have a habit of sealing up when the engine warms and confounding well meaning troubleshooters.
ticking (not what I'd call a knock)- does it increase with engine speed or stay steady? It sounds like it comes from the valvetrain and/or lifter. that will increase with engine speed... break out 'ye redneck stethoscope (southern rednecks use a stretch of old hose, our northern counterparts like to use long screwdrivers to the ear and poking around the engine with the other end to isolate the noise; make sure and put the handle end, if'n yer a yank, to yer ear, not the pointy end- if you choose otyherwise, have somebody make a video)...
Noted! I'll take a look tomorrow and perhaps some pictures as well.
ticking (not what I'd call a knock)- does it increase with engine speed or stay steady? It sounds like it comes from the valvetrain and/or lifter. that will increase with engine speed.
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Does increase when I gradually accelerate, but seems to disappear once the RPMs get around 1.5 or 2. Probably since the engine(?) is so loud that I can't hear the knock/tick (lol). Let me tell ya...the cab can get so unbearably loud that I sometimes wear earmuffs.
I'm not sure if it's the o-rings, but I'll check it out when she's cold. The injectors and fuel rail are somewhat new.
Took a look underneath and things seem okay, but I'm pretty sure new mounts are in order, since I know they have never been changed.
However...
I did find this thing torn in two. Any clue on what this is? This is by the left front wheel and seems to connect to a circular gear housing similar to the C8.25 on the back, except it's smaller.
EDIT: It's connecting to the front differential and it looks to be a torn hose of some sort.
that's a vacuum hose, my friend- which explains the 0455 evap....
do these things use an air cad to engage the 4wd? if so, yours doesn't work.
go to lowes plumbing department and ****** up a two sided nyon barb fitting of the proper diameter, and/or some proper length hose... fix that and a lot of your issues will disappear.
high pitch whining?... fuel pump.?.. put ear under rear of jeep under gas tank and listen... you hear it whining ? they will make a noise you will think you got a bee hive in the cab with you
that's a vacuum hose, my friend- which explains the 0455 evap....
do these things use an air cad to engage the 4wd? if so, yours doesn't work.
go to lowes plumbing department and ****** up a two sided nyon barb fitting of the proper diameter, and/or some proper length hose... fix that and a lot of your issues will disappear.
All I know is that my 4WD is Command-Trac and I engage it with the very manual-looking gear shifter next to my AW4 shift in the cab.
I'll have to find a good toolkit for all of these parts!
Took a look underneath and things seem okay, but I'm pretty sure new mounts are in order, since I know they have never been changed.
However...
I did find this thing torn in two. Any clue on what this is? This is by the left front wheel and seems to connect to a circular gear housing similar to the C8.25 on the back, except it's smaller.
EDIT: It's connecting to the front differential and it looks to be a torn hose of some sort.
It isn't a vacuum line. That is your diff. vent tube. My son's looked just like that. Front drive shaft ate it in to.
Fixed the vent hose, changed oil, still has a tick/knock and I'm wondering if it isn't either the flex plate or timing chain on the bottom there? Thinking about replacing the chain anyway. She's at 143,000 miles just about.
Edit: Gasoline smell isn't from the injectors or o-rings, either. It seems that when the engine is cold, a richer fuel mixture is used, thus the smell??
08-28-2016, 07:56 PM
Engine Problem?
