I replaced the crankshaft position sensor last week and also replaced it about a year and a half ago. I have not changed the camshaft position sensor. I'll look into it but I believe that usually throws a code. The genuine parts for the camshaft sensor are a couple hundred dollars but there are some cheap $30 ones around. I might throw one in just to see if it catches.

I'm running out of time on this, I have to move on the 30th so will have to tow the Rover if I can't get it up and going by then... Awful timing. Will try an ECU/BCU swap next, will report back tomorrow on that.

 

I feel your pain buddy, I was without my Disco for over 4 mo. Initially had it towed to 2 mechanics; first (non-LR-savvy) said was a timing chain issue, without even trying to look for the fault; the second (a LR-savvy) recommended I replaced the engine, at which point I towed it back to my workplace's parking lot (thankfully I had that option); while there and with the help of this Forum I dove into it myself, replaced Coil Packs, Sparks & Wires (CPS sensor had been replaced by last shop, but used a cheapo from Advanced I brought them); and after a jump start, it ran... lasted a couple days when it shut off for the first time a stop light near home, so had to tow it home. A couple days later dove in myself again and replace CSP sensor with a Bosch one, and it ran again ...after 20 days running perfectly it shut off again at a stop light, and had to tow it to a third mechanic; he suggested it was the immobilizer, but with feedback from Forum and gut, decided to tow it back to workplace's parking. At that point I did not want to deal with it myself, so after recommendations from Forum, I contacted two of the nearby mechanics recommended, both responded, but one was more interested in helping, but wait time was over a month. He has had it since September 9th, so over two months checking things out, until decided to swap fuse box and voila! ...final word, it might be worth looking for a reliable LR mechanic wanting to go the extra mile with you in figuring it out. I just did not have the space, the time, the tools and the knowledge to go as far as my mechanic did (Norman in Pompano Beach). Will be picking it up in a couple of hours, and report back any updates. Which I can be of more help.

 

So the ECU/BCU doesn't work in my Rover so I can't try that. I did a compression test today in cylinder 1 and it was around 30psi with ignition and fuel off. So my next question.

How can I rule out timing chain vs head gaskets vs anything else?

I did head gaskets about 4000mi ago due to significant oil and cooant leaks that slowly developed. Can they fail suddenly and quietly?

 

Check the compression in the other cylinders. Pull the fuel pump relay while testing and hold your foot to the floor. Check at least 4, two on each side. If they are all 30 you almost assuredly have a broken timing chain. You can pop a valve cover off and see if any of the rockers are moving.

 

With the ignition off? Did you crank the engine by hand or with the starter? Did you jump out the starter somehow? You need to crank it with the starter for several revolutions to get a good reading. If you used the starter and only got 30 psi, you need to check more cylinders like Extinct said. If all are low, you have a timing chain or camshaft issue, ASSUMING your head gaskets are good.

 

I'm going to assume the head gaskets are okay in this case and go with a likely cam or timing chain issue.

I checked two cylinders on each side with fuel pump relay out and pedal to the floor.

Cylinder 1 - 30psi
Cylinder 5 - 27psi
Cylinder 2 - 0psi
Cylinder 6 - 3psi

So I know I'm screwed based on this but where do I start to unscrew myself?

Would a sudden failure of timing chain be audible?
Can failure of the camshaft sensor cause this and not throw a code?

I meant to say earlier that I had taken out the fuse to the coils, not ignition, when doing the compression test. Though I could technically power the starter without powering the ignition since I have a starter toggle.

 

You have to start somewhere, easiest thing to check first is pull the upper intake and a valve cover to see if any rockers are moving. You have to pull the oil pan and everything off the front of the engine to get the timing cover off. ..which you'll have to do anyway if it's the chain. But if it's a bigger problem like a worn or snapped camshaft, you'll know with a valve cover off. A bad cam sensor will not cause low compression, it has to be something mechanical. My money is on the timing chain/gears. ..May not hear it go, doing 90.

 

timing is likely good

I ran one at high rpms for a long trip and it ate the valve seats. That is why I asked about the compression test. Put a bit of oil in the cylinder before you run the test and see if it has any change

 

Been a long couple weeks, just got around to doing a compression test with some oil down cylinder 8.

Before oil - 30psi
After oil - 70psi

So does this definitively tell me this is a valve seats problem? All help has been much appreciated. Just want to know I'm on the right track before I buy a kit to replace the valve seats.

 

You can do a leakdown test and see where the air is escaping, valve cover it is a ring problem, intake or exhaust it is a valve problem.