98 Catera Crankshaft Position Sensor Replacement - Cranks Won't Start

[sirmqc]

The procedure to replace the Crankshaft Position Sensor (CPS) is below with pictures - you can skip these first sections if you choose, its mostly my ranting.

My Symptoms: Here’s what my car did. The problem started with occasionally taking longer cranking before it would start. Then it sometimes would crank, but not start at all after it had been running (or sometimes start with alot of cranking). I could wait 5 minutes, 30 minutes, an hour, or overnight and it would start – it seemed to be random on when it did it and how long I had to wait. This went on for a couple months, with it happening more severely and more frequently, but still random and intermittent. Then one night after work, it wouldn’t start at lunch. When I went to leave in the evening it still wouldn’t start. I tried disconnecting the battery for 30 minutes, but that didn’t work. Next morning, still no start. Had it towed to the dealer, they replaced the fuel pump ($800!!! I’ll rant about this in a minute). The car ran fine for almost two weeks, and then started the same symptoms. This time it only took a few more weeks before it wouldn’t start at all. This time it was at home. It was getting no spark. I disconnected the battery and charged it and when I reconnected, it started right up. After one day of driving, it again wouldn’t start at home. After checking for fuel (fuel pump was working) and spark (no spark) and trying other stuff, the battery was low. I disconnected the battery and charged it and it started. So I was thinking that disconnecting the battery was resetting something, so I drove it to work. It wouldn’t start – I disconnected the battery for 30 minutes, then an hour, then overnight while charging the battery, and still crank but no start. I had it towed home. I installed a new Crank Position Sensor (CPS) and it started right up and has been fine for almost 2 weeks now. Some other people had there CPS cause the car to die while driving, or go out all of a sudden. Mine apparently was intermittent for several months. And its important to note that it always cranked normally, and the engine light never came on. And when it did start, it always ran perfectly fine – this was the most confusing to me and the reason this dragged on for so long.

About the Cadillac Dealer Shop (a certain, unnamed dealer shop on the north side of Indianapolis...Tutwiler...oh, did I say that out loud?): So from my story above, I had it towed to them and they determined that it was the fuel pump. I asked if they scanned it – they said they had and that it had no codes. I asked how they knew it was the fuel pump – they said that when they hit the fuel tank with a rubber mallet while cranking the car, they could hear the pump spin up for a second. Ok, that sounds reasonable. I took them at their word and coughed up the $800 bucks – I would have attempted this, but my wife was eight and a half months pregnant and I wanted my car to be ready for THE CALL – and I didn’t really have time to mess with it. So I’m sure its possible that the fuel pump and CPS were going out at the exact same time. And the first no start was caused by fuel pump and the subsequent no starts were caused by the CPS – and they just happened to have the exact same intermittent symptoms... yeah, right. OR maybe the dealer just suspected an intermittent pump and threw one on. Even if the pump was bad (and I doubt that it actually was) they still did a poor job diagnosing the problem. The CPS is a common problem on Cateras with these symptoms. The justification for the astronomical labor rates is proper equipment, training and experience to work on Cadillacs. They obviously didn’t have any of this in my case since my problem was mis-diagnosed, or at the very least, incompletely diagnosed (assuming the fuel pump was bad). I thought I was paying for premium service – what I got was royally screwed. Oh, but they do have a “free car wash with service” policy, so I did get my car washed – it only cost me $800. Fantastic. Next time I’ll take my chances with a random mechanic – I may still get screwed, but at least it won’t cost as much.

A quick note about the Service Manuals for anyone that is considering buying them: I’m a novice mechanic, so maybe its just me – but the service manuals don’t seem to be as useful as I thought they would be. The diagrams are often useless – It took me over an hour of looking at the CPS connector diagram and staring at the engine from every possible angle before I found it. And the procedure doesn’t tell you to remove the wiper arms or vent; I don’t see how you could possibly get to the connector without removing them. The index of the manual does not even come close to listing all relevant sections that pertain to the part\term you are looking up. There is alot of very useful info, but its difficult to find and sometimes incomplete.

Crankshaft Position Sensor Replacement

[See picture 1]
The first step is to remove the windshield wiper arms. A tip that I thought of too late: use tape on the windshield to mark the angle at which the arms are attached. Remove the round plastic cap, then the nut from each arm. The arm is wedged onto the cone shaped bolt, so you have to use some force to work it loose. The manual says to - grip the arm with both hands and use a rocking motion - whatever that means. Use some force and pull the arm back and forth in the direction that the windshield wiper would normally move. Eventually it will break loose and move pretty freely. You then have to relieve the tension from the spring-loaded hinge on the arm to be able to lift it off the bolt. You'll figure it out. Make sure to remove the round foam-rubber rings that are under the arms. You don’t want to knock one off and drop it down into the engine compartment and then into a hole in the frame, never to be seen again... not that that happened to me or anything. Tip: use a rag or towel to keep the arm from rubbing/banging against the hood.

[See picture 2]
Next remove the plastic vent cover at the base of the windshield. There are about 5 plastic screws under the rubber seal at the bottom of the windshield. The picture shows one of these screws in the locked position. Rotate the screw 90 degrees to unlock it and it pulls straight out. Use needle nose pliers (or whatever) and pull these screws out - otherwise you'll break half of them when you pull the vent cover off. There's one additional screw on the driver’s side that holds the vent cover to the car body. The driver's side of the vent cover should now be able to be removed - there's about a 2-foot section on the passenger's side that is separate and doesn't have to be removed.

[See picture 3]
With the vent cover removed, you should be able to dig behind the engine and find the CPS connector, but just barely. Look at the picture below.

[See picture 4]
The big connector in the middle was in my way, so I disconnected it and pulled the two ends out of the way. Look at the next picture and you can see the two connector ends pulled out of the way.

[See picture 5]
The CPS sensor is attached to the back of the aluminum bracket In the middle of the picture. It takes a little work to get the clip off the metal bracket, and then get the clip and CPS connector to a position you can unclip them.

If you’re unsure about whether the CPS is the problem, you can try this (I thought of this too late, but you can learn from my mistake). Just drop the new sensor down the back/side of the engine, attach it to the engine, and plug in the new sensor. If the car starts, you can remove the old sensor and route the new sensor along a more permanent route. If it doesn’t start, something else is the problem.

To remove the old sensor, unbolt it from the engine block. The sensor is right next to the oil filter, is sort of egg shaped (round, but wider on one side than the other) and held on by one bolt. If you get the car on jack stands or ramps, you should be able to easily see the oil filter and CPS by getting under the car right behind the driver’s side tire.

An aluminum heat-shield sleeve covers the first section of the CPS wire. The original routing of the wire seems to pinch the sleeve between the oil cooler lines and the engine block. This makes removing the old wire a bit difficult. Here’s what worked for me. Once you pull the sensor off the car, twist the sensor so that the wire twists and breaks free from the heat shield. Then cut the wire at the sensor end. Next, pull the connector end to pull the wire free from the car. I had to twist the connector end as I pulled to get it to come loose. And the shield didn’t come out, just the wire – I don’t lose any sleep over having the empty shield still in there.

[See picture 6]
Next you have to route the new CPS wire. You can see the general path from the stick in the picture. I placed my work light on the top of the engine at the back, then got under the car and looked up to be able to see the general path. From under the car, I ran the stick up the back of the engine and out the top. I then taped one end of a piece of speaker wire (that was a little longer than the CPS wire) to the end of the stick and secured the other end of the wire to the windshield wiper arm. I pulled the stick down and used the speaker wire to figure out my path. Make sure the final path of the CPS wire stays clear of the exhaust manifold – I also tried to avoid the coils as much as possible to minimize signal interference (I don’t know if this is a big deal or not). Then I attached the sensor connector to the wire end under the car and pulled it up and plugged it in. Make sure the CPS wire is routed where you want it and install the sensor and bolt it in. (-Bonus Question: what’s wrong with the picture above – besides the piece of wood sticking out the top of the engine of course?)

Install everything in reverse order – reattach the CPS connector to the clip and attach to the bracket – reconnect the big connector that was in the way – install the vent cover (this can be a bit tricky to get aligned) – install the windshield wiper arms (use the tape marks to line up the arms, or make a rough guess like I had to do) – fire this bad boy up!

[sirmqc]

I couldn't get the pictures inline with the text like I had in the word doc I created - I guess this will do.

There were alot of people asking about Crank sensor location and replacement. Hopefully my sharing this will help a few people, just like this forum has helped me out of a bind - and most likely future binds.

I found a new CPS on ebay for $40 by the way - Autozone could order it and have it in 2 days for $70.

[inconnu]

Good post.i would agree with you on service manuals they are not that useful the other day i was looking for illustration on changing the valve cover gaskets and i couldnt find any or may be i missed a page or two

[sirmqc]

My valve cover gaskets are just starting to leak - I guess I'll have to find somewhere else to get the procedure from - there may have been a post on here about it - maybe in the tech forum.

[Lcsolutions]

Not meaning to sideline this thread, but I have a gasket question: I am seaping oil into the spark plug areas around the coils..... is this the infamous valve cover gasket leak?

Thanks!

Joe

[sirmqc]

Thats what they say - there's quite a few posts about it on this forum. If its bad enough, it is said to cause spark plug fouling and damage the plug wire boot.

[1986cimarron]

Document ID# 193643
1998 Cadillac Catera


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Camshaft Position Sensor Replacement
Removal Procedure




Disconnect the wiring harness from the Camshaft Position (CMP) sensor (1).
Remove the A/C Low Pressure line bracket.
Remove the fastening bolt for the CMP sensor.
Remove the CMP sensor and the O-ring seal from the camshaft cover.
Installation Procedure




Thoroughly clean the mating surfaces of the CMP sensor (1) and the camshaft cover.
Install the CMP sensor with a new O-ring seal into the camshaft cover.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Install the fastening bolt for the CMP sensor.
Tighten

Tighten the bolt to 8 N·m (6 lb ft).

Install the A/C Low Pressure line bracket.
Connect the wiring harness to the CMP sensor. Ensure the correct cable routing.

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Document ID# 193643
1998 Cadillac Catera

[jlzozosky]

I thought I was going to have to kill the mechanic who ran the cps sensor wire in my catera, but it sounds like it is routed incorrectly from the factory. Thank god I found this thread because I was about to pull my hair out! Thanks sirmqc!

[Marks DTM Calib]

Don't route the cranks sensor wire in this manner.....the failure route cause is down to the oil cooler lines heating the cable and causing fractures.

The best route is to route it around the side of the engine bay near the ABS modulator, this avoids the exhaust and hot rear of the engine. Cable tie the wire to avoid damage.

Note also, the cam sensor is bomb proof!

And if you have leaking camcover gaskets then the chances are the engine breathers are probably blocked....

For details on camcover gasket renewal, see here:

Cam cover gasket renewal

[berniem]

My friend just went through the identical experience with his Catera: same symptoms, when it starts the car runs fine, tow to garage, rubber mallet to the gas tank, new pump for $800, same problems, OBD reports CPS fault. Going in for new CPS tomorrow, mechanics dont want to work on it. Thanks for helping me help him. Now I need to fix the intermittent climate control on my Ford Taurus.

[moerome]

Dude:

I had the same symptoms as you described. I was looking for this post to reply to it, but ended up creating a new thread to describe that I STILL have the issue (see the post, "Just Bought CPS, Still Won't Crank).

Your block of instructions were awesome!! I had no problems installing the CPS on my '99 Cat. Unfortunately, the symptoms returned about five hours later while at the petrol station. Any other suggestions? Thanks.

[ceaborn]

I found that the whole job was allot easier after I dropped the exhaust on the drivers side for ease of access to the CPS, without dropping it you will have to have some pretty small hands and allot of patience. I had photo's but they were lost when my computer crashed the other day If you do drop the exhaust you can count on the bolts behind the cat breaking off, both of mine did and I had to drill them out and use a bolt and nut instead.

[ceaborn]

I still had these pictures stored on my digital camera after my computer crashed.
These pictures will hopefully give you a little clearer perspective on where the sensor is and how to get to it.

Link... http://www.cardomain.com/ride/2184514/6

[dwn]

I "just" (5-19-07) bought a 97 Catera, I almost didn't after reading here about all the problems with the car but the previous 2 owners have all ready gone through what I hope is most of the hard times... I think I got it for a good price because it has, guess what, a miss.. They last owner put in about $1000 trying to fix it, no luck... When I took it for a test drive I drove right over to Autozone and had them scan it... Can up with 2 codes - 336 which is the CPS and 302 which is a miss at the number 2 cylinder, I think (no I hope) that the 302 is because of the CPS problem... I was trying to figure out where the CPS was, WOW is it tight in that engine compartment... I'm sure glad that I kept reading these posts.. Thanks for the info above, as a new owner I REALLY APPRECIATE being able to learn from everyone here...

[Po Pimp]

Bonus question.

I believe you are missing a bracket on the back left side of the manifold that holds some wires.

Good write up by the way. Unfortunately I had to use it for guidances as my Catera did not want to start.