new to the site trying to get some answers..bought a 2000 jeep cherokee 4.7 100k miles to fix..well got it home got valve cover off to see timing chain on driversside was off ...i bought new timing kit got it in put back together an now it seems to run more poor than it did with the timing chain off.. before it would idle now got the timing kit in an will not idle at all i have to hold throttle atleast halfway to crank an to keep running ..started doing compression check did the 1st 3 on driverside an it read 0... if it were bent valves wouldnt it read some compression ? some one has told me from another forum site that is has to be out of time....any opinons on whats going on here? or do i just plain an simple have severe damage to my head (vlaves bent piston damage?)

 

it does sound to me like the timing chain is on incorrectly, expecially if you had compession before you changed it

 

No if the timing is off you most likely will not have compression reading, or maybe some. You need to pull the front end of the motor back off and ensure that you in fact do have the cams and crank lined up correctly.

Usually when this happens you accidentally have the TDC incorrect, meaning when you placed the timing components on the mark, well in actually the motor was on exhaust TDC and not compression TDC.

When you set the timming you have to ensure that the #1 (drivers side front piston) is at the top, not the bottom (meaning it is at the top of compression stroke). To do this you pull the #1 spark plug and turn the motor clockwise (WITHOUT TURNING BACKWARD AT ALL) until the motor crank pulley states TDC center appear on the corresponding arrow viewed from the top side of the motor, AND the #1 piston is at the top of the cylinder again verified buy placing a long screw driver down the empty spark plug hole on #1 at TDC (Top Dead Center).

At this point you place the cam's and the crank in position as the Service manual states and place the timing chain on the motor.

Now these instructions go for ANY motor that I know of. Then tentioning and this and that comes after these instructions.

Please induct this to DIY timing instructions please.

 

ok i got the front off again im trying to determine if its all on correctly how can i do this without taking it all apart i can get it to tdc with the front chain looks right the one dot on bottom an top 2 links are lined up then when i look threw the hole to see the cam chains the 2 links arent there? are they going to be lined up to,if the crank chain is lined up? also i didnt check compression before i should have but didnt ..i took 3 of the driverside plugs out an did the comp. check an all 3 was 0 i thought my gauge might have been broke but did one on passenger side an it was good

 

Not sure exactly what you are asking, however download a copy of the 2002 Durango Service Manual and look at page 1074. You first have to make sure your engine is at TDC using the Damper mark, then ensure the piston is actually at the top of the cylinder on #1 (which is the drivers side front plug toward the grill). You do this by taking out the spark plug and with a long screw driver or something thin slide it into the spark plug hole and see if the piston is at the top, you might even be able to see it with a flash light.

Now once you have done this you need to look at your cams both left and right and ensure the V8 markings both at the 12:00 position and that the tensioners are to specifications. If not put it right.

If you can find no issues then there would have to be something wrong with the head.

Again, look in the manual as it shows the positions of the cam gears, and remember the damper pulley must be on TDC compression stroke, not exhaust stroke which with the damper on TDC the piston would be very far from the top on #1.

 

its all right ...im taking the head off tommorow

 

Take off the valve cover, your rocker could have just fallen off. Its happened to a few others around here