Michiana Jeep Club

I suspect that the bearings did not recieve adequate oil..possible journal plugged.. still inspecting.
My jeep is back down in Nappannee at the rebuilder. will keep you posted. see the white flakes which appear to be molten bearings..had flakes in the oil pan when removed as well.

Hope the rebuild had a warranty

The inline six is not designed for 10,000 RPM.

You told me it was at the cam journal... confused.... NOT GOOD!! a spun main bearing could spell disaster for that motor!

Hope it all turns out good for ya - tough break John..

Engine has been pulled and main bearings inspected. All main bearings where starved of oil which helps confirm that the oil pump stopped pumping resulting in failed/siezed up bearing at the farthest point (front) main bearing.

Codes: P0340 camshaft position sensor A circuit bank one or signal sensor
P0353 ignition coil C primary/secondary circuit
P0352 ignition coil D primary/secondary circuit
P0351 ignition coil A primary/secondary circuit

story from rebuilder:
1) Cam Position Sensor pin sheared (gear stayed in position and turned irradically)
2) CPS sends pulse info to CPU that sends info to Injectors (not spark) therefore engine kept going and oil pump did not.
3) starved oil at main bearings siezed up.

I get different information on what a CPS does.

Haynes Manual says "It replaces the distributor used on earlier models"

EHow: Kyle Sanstrom

The crank position sensor in a Jeep Cherokee is designed to record information about the revolutions per minute (rpm) and relative position of the crankshaft. The crank position sensor sends this information to the engine control unit (ECU). The ECU processes this information and uses it to manage the Cherokee's engine. When the crank sensor goes bad, the ECU can't determine when to fire the ignition, resulting in an inability to start the engine.

EHow: Kyle Sanstrom

The crank position sensor is responsible for reporting the speed and position of the crank shaft to the engine management computer and if it is not working, the computer can not adjust the spark, fuel map or other parameters, and the engine will not run properly.

Rich at Cherokee Forum said:

To clarify and stop the rumor:
The CPS is NOT a Hall Effect Device. There is no semi-conductor materiel in it. And it does not require a separate Voltage to power it.
It's simply a magnet with a very fine wire wrapped around it.
The wire breaks inside, or the pigtails attached to the fine wire breaks. Often it's the connector that gets corroded. Unplug, plug back in - fixed!
It provides the pulse to tell the PCM when to fire the injectors and when to make the spark.

I do not recall chime and "check gauges light" on my 5 minute ride home from Reed farm. I would of noticed no oil pressurte and immediately stop.

Can a high oil pressure pump cause problems? Does the CPS send info for spark?

Having rebuilder quote fix..new Crankshaft, bearings , full motor inspection

OUCH!!!

First off you can`t continue to use CPS. Use cam sensor or crank sensor. 2 of the quotes are for crank sensor not cam sensor. The root cause was the fact a high pressure oil pump was used! It may have "washed" the bearings causing the seizure. A high pressure pump also adds more stress to the pin for the gear on the cam sensor. If the oil pump was turning erratically so would the cam sensor thus affecting the signal to the CPU to fire the injectors. Even when the engine was running like crap I NEVER heard any noises alerting me to a no oil pressure issue. It doesn`t take long for the rocker arms to make noise once oil pressure drops. I still stand by that the bearings were washed causing the bearing to startto spin thus closing off the oil feed holes which also push oil to the cam sensor gear. This may have starved the gear ofoil causing the pin to shear. I still say the oil pump caused this mess. Just my $.02.....

Mike,
I think you may have a valid point on High Pressure/High Volume Oil Pump..found these comments on the net..

Hi,
I am the tech manager for Fram filters, also just a regular mechanic that owns a shop specializing in engine repair. You should replace the pump and pickup if your going to remove the pan, use mellings or trw pump. There is no reason to install a high pressure or high volume oil pump! Jeeps have a poor oil pressure sending unit/guage. They are very inaccurate and can fluctuate. I have seen many Jeeps in my shop with sludgy oil pump pickups. I would replace the pump and pick up with a stock pump and pickup, then hook up a manual oil pressure guage if you want accurate oil pressure readings. A high volume oil pump will cause excessive HP loss, less fuel economy, greater chance of leaks. they are for race cars, trust me.
Good luck

There is no need for a high-volume pump. The system works very well as-is.
A high-volume pump will put more strain on the distributor (or cam-sensor depending on year) gear and roll-pin... I am already seeing roll-pins shearing off with stock pumps, it will be worse with a high-volume.
Sheared roll-pin = Jeeper walking or waiting for the tow truck

Any updates????

Who put in the high pressure oil pump, the rebuilder ?

i agree mike, without putting extra clearances everywhere oil escapes a bearing, a high volume oil pump is the worst thing most inexperienced rebuilders do, and that is most likely the root of the whole thing. period. if all the side clearances were/are stock, then so should the volume of the oil pump..... trying to pump a gallon of thick oil every second through all those tiny oil passages escape routes, creates tons of stress's, and actually reduces horsepower.( IMHO)... just my.02,


:)john i still have an all aluminum small block chevy

When I first started this motor I told john it had to much oil pressure . I'd had asked john what pump they had used. He didn't know. I agree with Mike and Clint. . That is a common problem with novice builders.
No matter what the builder should stand behind his rebuild and his parts!!!. After all he's the one who chose those parts and assembled it. !!!!!!

Orange rubi wrote:When I first started this motor I told john it had to much oil pressure . I'd had asked john what pump they had used. He didn't know. I agree with Mike and Clint. . That is a common problem with novice builders.
No matter what the builder should stand behind his rebuild and his parts!!!. After all he's the one who chose those parts and assembled it. !!!!!!

troy, very right, john should you need muscle to talk to your builder, let me know... im sure a few of us wouldn't mind standing behind you with dark glass's on...lol

"LIKE" button hit!!

As most of you who know . Me. I won't need dark glasses. To speak. I want them to see my eyes. . I'll be beside John if need.

X2 Zuke = "LIKE" Button hit!!!

"JEEP MAFIA".....