99 Dodge Ram 1500 with 318

Searching the internet I found a post that said my crank position sensor is on the bell housing adjacent to the rear of my passenger side exhaust manifold. I can't see it.

Does anyone know if this is where it is and what the best way to get at it is?
I also read that it was mounted with two 1/4 inch hex drive screws - can anyone confirm?

Thanks,

Frank

 

Yes,

It is a blind job, because you can't see what you're doing.

The sensor is behind the passenger side valve cover and exhaust manifold. It's a PITA to get to. If you crawl under your truck and locate the oil filter and then look up toward the exhaust manifold on the passenger side, you'll notice a little steel flange bracket with 2 bolts holding it down. That's the little bugger right there. Here's a thread on how to get to it if you are having problems:

https://dodgeforum.com/forum/2nd-gen-ram-tech/130645-crank-sensor-mod-for-those-with-big-hands.html

 

I found the best way to attack it was from the top, but its a tight fit even to get your hand in there. Its a PITA to get to is all.

 

Thanks guys, I plan on attacking it tonight. I'll let you know how it goes. Frank

 

Like you said, it was a PITA. I looked from underneath first to see where it was and then from the top was able to feel it and get the 1/4 hex into the bolts and remove it with no problem. To get the wire connector apart I had to pull the removed sensor over to the harness where I could pull both directions on the wiring. Inserting the new sensor back into the rubber grommet was also a PITA and I didn't think I'd ever get the second bolt started. I drove it to work this morning. I'm going to get Auto Zone to test the old one - if it tests good I guess I won't know if the problem (truck dies while going down the hiway) is fixed until I drive it for a while. Thanks for all of your help, Frank

 

The Crank Sensor is just a magnet that records the ticks in the flex plate to set the timing. Either it works or it doesn't, and it should be read by the PCM at startup as well. Check your voltage on the pre-cat O2 sensor to see if it's sweeping funny. If it's bad, it'll lean out the engine to a stall. running lean constantly isn't a good thing either.

 

I'm not being defensive here I just want to explain how I got to where I am. The truck was dying while my daughter was driving it, the first two times, by the time she got to the side of the road it started back up. The third time it wouldn't start and we had it towed to a shop where it showed no diagnostic codes but started back up and wouldn't die for them. I then drove the truck 4 hours home and then 60 miles round trip for two days and then it died on me at 60mph on the next day. The shop told me that the crank position sensor on this truck has a history of failing (temporarily) and not leaving any codes. (I had an 88 318 that the distributor pickup plate did the same thing on) That being said that's why I did a trial and error replacement of the crank position sensor ($75).

The pre-cat 02 is the pre catalytic converter oxygen sensor? Are there two, one on each exhaust downstream of the manifolds? What kind of voltage should I expect to see from the sensors - what does sweeping funny mean?

Thanks much for replying, Frank

 

Check your wiring harness to your PCM. I've heard of guys trucks dying (especially while running a jet chip) because the wiring harness would work it's way a little loose and temporarily lose connection from vibration. You may have already checked it, I just thought I'd mention it since it's easy and free to check.

 

I'll check it. Thanks, Frank

 

No offense taken, it's possible the crank sensor isn't working, there might be a short in the wires that run around the back end of the engine, I'm just throwing out other possibilities for you to check.


there are 2 sensors in the truck, unless it's a California emissions Truck then it has 4. The Post cat sensor just tells the PCM that the cat is in good working order. The Pre cat sensor leans and enriches the fuel mixture.
This link should tell you more than what you want to know about O2 sensors:
http://mr2.com/TEXT/O2_Sensor.html

It could also be a failing ignition coil that's giving up after it's been put under load for an extended time. Or, I've read that fuel pumps can sometimes go slowly if they are partially blocked.