I'm getting 2-1-4 error code. Looks like my RPM sensor (crank shaft positioning sensor) is failing. It's manifesting itself in intermittent hard starts, cutting out while moving, or simply shutting down. It will restart, and run fine for a while, but it will fail again. I wish it would simply die...
Anyway, I would appreciate tips on how to replace this sensor. I can tell it's hard to get to. I'm not afraid to tackle this job. I have the tools and will to do it. Thanks in advance!

Andres,

In addition to trichard and rich, and this helps if you motor mounts and transmission mount are sagging or failing ....

RPM sensor, engine position sensor, crank (shaft) position sensor ...

I have a scissor jack that is somewhat small and flat. Unlike the Volvo 240 scissor jack, this scissor jack does not have a saddle.

I place padding on the firewall and the rear of the #4 exhaust manifold and the saddle-less scissor jack in between.

I then open the jack slowly.

The engine moves forward.

Keep your eye-bulb on the the failing crank position sensor at the top of the bell housing. You want to see the top of the RMP sensor retaining bolt.

You can use some sort of adhesive or a magnetized six-point 10 mm socket. Depending on how comfortable you are on how far you can bring the engine-transmission forward enough to give you conformable access to the bolt.

Some will not want to use a magnetized socket, or a socket with some sort of adhesive in it. Some will want the assurance they can grab the retaining bolt with their fingers.

It is not that the RPM sensor retaining bolt is a rare design. It is that you do not want to lose it.

Some have report losing the retaining bolt down the hole the sensor goes into.

Some may slid the retaining bolt through the hole of the new sensor, and with this in hand, lower it into place so the bolt rests on the bolt hole, and an easy application of the 10 mm socket allows you to tighten the hardware and apply torque.

One the new RPM sensor is secured and the cable routed properly, lower the jack, the engine will return to its seated position, and with draw the jack.

One 700-900-90 series is a plastic retainer that, at one end, clips to the B230 oil dip stick tube, At the other end, it secures the RPM sensor cable from flapping in the turbulence as you drive you Volvo 240.

Questions?

Hope that helps.

Thanks.

Monday Morning MacDuffy's Tavern.

1. 1/4' rachet drive, with 10 inch to 1 foot extension and 10 mm socket attached to swivel which you tape to reduce the swivel to a minimum
2. un fix the harness at the welds and pull towards the front the car and tie off so it remains away from the firewall
3. move ground strap if needed there as well
4. place strong cordless light under the #4 spark plug against the firewall pointing upwards
5. from directly above and the middle of the valve cover lower the socket attached to extension while looking at the objective from the passenger side of the car
6. taping the swivel will make it easier to control the tiny controlled movement needed here to gain access to the bolt
7. remove bolt and CAREFULLY try to swivel the sensor in its bracket. most come right out BUT if oil and dirt have made your hard to move be VERY careful as you attempt to loosen it up to remove.

in fact i am now removing an automatic transmission from a 91 wagon its slob owner was too rough doing this job and cracked off the bracket. if you break this aluminum cast bracket you're in world of hurt.

big tip:

on the re install place the bolt into the socket and run a thin bead of sticky butyl rubber around the edge of the socket so the bolt remains in place. you will understand why if you do not do this.

I did this job once. I had to put a 2"x4" across the strut towers and then a piece of plywood across that and onto the radiator support. So essentially I had to do a belly flop on the engine to get back down there where the fire wall is. It wasn't a fun job and took me longer than I expected. But you can do it with some patience.
--
1992 Volvo 240 & 1998 Volvo C70

This is a good idea and the older I get the gooder it is.

Rich (near Pittsburgh)

I agree, and if you do it this way, you don't need any ratchet or fancy collection of extensions. A 10mm combination wrench is all you need to bring to the job.

It helps a lot to scope it out with a flashlight and mirror so you can relate what you see to what you do by blind feel.

Hi Art,

Having attempted this method using a 2 x 6 with padding on the strut tower, I'd be wary of precarious positioning over the engine with all that stuff on it.

If you are a tall or large person, or even of medium stature, placing such force on the top of the radiator (or radiator brackets) on top of the cross member, that holds the hood latch, may be distressed.

And you can easily do this with, as I'll guess, as many 240s right now have, failing, sagging, or broken motor mounts with little or no clearance back there.

Though using using a scissor jack, or some manner of come along to move or pull the engine forward a critical inch or three.

Some may be worried of questionable exhaust manifold studs or gaskets. All three sets I have are in fine fettle, though.

Using a scissor jack, or come along, to pull the engine forward, works fine.

I pull it further forward. While using several 10" extensions or so, I'm able to keep my hand on the sensor, bolt, and the six point socket from removal all the was to catching thread to secure the new sensor.

The sensation is not like replacing this same sensor of the later RWD models with more room to do so. Oh well.

Thanks.

Nope.

I just did one and it is a pain-in-the-ass job, although there are worse. It seems every time I replace a Crank Position Sensor (CPS), I do it differently, but I can let you know what worked this time.

First, peer down into the area where the CPS is mounted until you can get a glimpse of it and form a mental image of its position - you'll need it later.

I tied a cord to the connector of the CPS before I separated it from its mate. I did that to retrace the routing of the lead so that I did have to try to decide if it went over this vacuum line or under that wiring harness, etc. Not necessary, but it eliminates any indecision.

I also loosened the tie wraps that hold the wiring harness which runs along the cowling pinch weld. I do not remember if I had to go behind the harness with the socket drive or just move it out of the way a bit.

I approached the CPS from above with a 10 mm socket on the end of two 6" long, 1/4" drive extensions, the working end one being a "wobble" extension. Instead of going in from the side, I stayed on the longitudinal centerline of the car and from above angled down and back until the socket engaged the mounting fastener. You will have to guide the socket home with you fingers since you will be working blind at this point.

I cracked the fastener and once loosened, unthreaded it the rest of the way by hand, I should say, by fingertips. Once the fastener was extricated, I pulled out the CPS, let my hand un-cramp, swapped the routing cord to the new one and then spent some time getting the mounting screw started before I could snug it up.

Don't waste your time trying to keep an eye on what you are doing. Once the location in space and time of the CPS is fixed in your mind, let your fingers do the walking.

Rich (near Pittsburgh)