I'm just starting to learn auto mechanics. My practice vehicle is a 2002 jeep grand cherokee laredo V6 4.0. The oil sending unit was going out so I took off what I thought was the correct part but actually turned out to be the camshaft sensor. I put it back on but now it will not start. A friend of mine says that it has jumped time. It's a distributorless system and he says to pull the #1 plug and use a screwdriver to move it to tdc. Is that possible since it is distributorless?
When I put the camshaft sensor back in after accidentally taking it out I started the jeep, it ran bad and rough and then died. Does that still sound like the oil pressure switch? Could I have caused it to jump time or is that not a possible explanation? I'm gonna put a new oil switch on it tonight. I noticed when I do attempt to start it the check gauges light is on because of the low oil pressure as well as the service engine light. If I don't turn the ignition all the way off and crank it again the lights go off because I get a little oil pressure on the gauge.
September, 28, 2012 AT 4:56 PM
Taking the cam sensor out should not cause it to jump time but if the wire connector is not secure, that could cause problems.
Symptoms indicates a possible ignition switch problem but I am not too sure if I understand your description correctly.
If you are able to crank without engine starting, you should be checking through the link.
What makes you think the cam sensor is faulty in the first place?
September, 28, 2012 AT 5:00 PM
I took it totally out of the block because I misunderstood and thought it was the oil sending unit. The jeep started before that just had 0 oil pressure.
September, 28, 2012 AT 5:08 PM
The sensor is only plugged in so you should ensure it is correctly seated and secured. Ensure the wire connectors are plugged in correctly as well.
September, 28, 2012 AT 7:54 PM
Disregard part of that msg. It's the oil supply drive I pulled out not the camshaft. The camshaft sensor sits on top of it which I at first I thought was the oil sending unit. Will that cause a timing problem?
September, 28, 2012 AT 8:20 PM
You pulled this out and yes, it affects the timing if it is not correctly installed. Here are the procedures to get it back into position.
NOTE: Fuel system synchronization is controlled by position of oil pump drive shaft assembly.
1. Clean oil pump drive mounting hole area of engine block. Install NEW oil pump drive shaft assembly-to-engine block gasket. Temporarily install a pin punch or drift through access hole on side of oil pump drive housing. Align hole on pulse ring with hole in
housing. See Fig. 57.
2. If engine crankshaft or camshaft was not rotated, go to next step. If engine crankshaft or camshaft was rotated, CMP sensor relationship must be adjusted, go to step 4.
3. Install oil pump drive shaft assembly into engine while aligning oil pump slot. Rotate oil pump drive shaft assembly to its original position. Install hold-down bolt finger tight. Go to step 5.
CAUTION: DO NOT rotate engine against normal rotation to align
4. Remove ignition coil rail assembly. Remove cylinder No. 1 spark plug. Rotate engine (in direction of normal rotation) until pressure is felt in cylinder No. 1. Slowly continue to rotate engine until timing mark aligns with Top Dead Center (TDC) (zero degrees) on
timing scale. Install oil pump drive shaft. If oil pump drive does not drop down flush with engine block, oil pump slot is not aligned properly. Remove oil pump drive shaft and rotate so oil pump slot aligns with shaft on bottom of oil pump drive shaft. Install oil
pump drive shaft and rotate oil pump drive shaft assembly to its original position. Install hold-down bolt finger tight. Go to next step.
5. Remove pin punch or drift from oil pump drive shaft assembly. Install CMP sensor onto oil pump drive shaft assembly. CMP sensor connector should be facing rear of engine (zero degrees). Connect CMP sensor connector. Install spark plug and ignition coil rail
assembly (if removed). Go to next step.
6. To verify correct rotational position of oil pump drive, DRBIII
scan tool must be used. Connect DRBIII scan tool to Data Link Connector (DLC), located below driver's side of instrument panel, near steering column. Start engine. Ensure engine is at normal
operating temperature. With engine idling, select SET SYNC from scan tool menu. Observe scan tool display.
7. If scan tool displays IN RANGE and zero degrees, procedure is complete. If scan tool does not display IN RANGE and zero degrees, loosen hold-down clamp bolt and rotate oil pump drive shaft assembly until reading is as close to zero degrees as possible, and IN RANGE message is displayed. Tighten hold-down clamp bolt to specification. Turn engine off. Remove scan tool.
September, 29, 2012 AT 12:11 AM
Ok good news. I did the first couple steps and got it started. Thank you guys so much for sorting through my confusion. Is your website secure to make a donation? Or do you have an address I can send a check to? Thank you so much again.
September, 29, 2012 AT 1:11 AM
Now that I got the jeep started again there is a terrible knock coming from the engine. It's coming from the same side as the cam sensor but I can't totally pinpoint it. It sounds like its around or under the ignition coil. It didn't do this beforehand. Did I cause something else to mess up. It's a loud knock. Oil pressure is good since I put the oil sending unit on. Could it be knock sensor?
September, 29, 2012 AT 9:48 AM
If you click the "UPGRADE QUESTION" link you would be able to donate and yes, the site is secure.
I am not sure what noise that is so you would have to fill me in with as much information as possible. Have you rechecked the installation of the camsensor gears as getting the gear off by a mark can cause performance and running problems. Did you try manually adjusting the cam sensor timing? Since you don't have the scan tool to check the timing, you might have to manually adjust it manually. Turn engine off. Mark the initial position and loosen the holding bolt and turn the shaft clockwise slightly and retighten. Try starting and and note if there are any changes. You might have to repeat with a few adjustment to get the best result. You might need to go counter-clockwise instead of clockwise.
Since oil pressure is available, it is less of a worry.