Over the last few weeks I've been putting some TLC time into my 03 Discovery. Partially because of her 140k miles, partially because she developed a severe oil leak somewhere at or about the front cover and partially because my 03 has had a pronounced low RPM tick for some time.

With this, I decided to replace: oil pump, timing chain, chain wheels, water pump and associated seals. I was most interested and curious about the oil pump.

Not so big / big surprise! After removing the oil pump cover I discovered the outer gear ring had split into four sections. Amazingly it was still pumping. Scarey, all it would have taken was for one of the sections to loose it's union with the others in the train and the pump would have gone catastrophic.

She's back together and I can't say for certain what the resolve was, but the tick is definitely gone.

Theory one: The sound I was hearing may have been a particular piece of the outer gear ring slapping against the wall of the housing as it turned through the cycle at low RPMs. At high RPMs the increased oil pressure may have cushioned the piece.

Theory two: Low oil pressure effecting something else. Unfortunately the start of this project was a bit spontaneous- having an unexpected window of opportunity to jump into it. I didn't do a before oil pressure test, but wish I had.

Theory three: Perhaps it was replaced the timing chain and wheels... (long shot)

So... if you 03 has a pronounced tick which seems to resonate from the front and sides of the engine, your oil pump gears may be split like mine were.

 

Sorry I didn't call you back, lost your number.

 

cams?

 

how much time did it take? any pointers for some of the work you did?

 

Hey Michael,

Glad to hear you got your tick sorted out. No doubt thy was likely the same issue that plagued my '03 as well. Keep us posted but it sounds like you finally tracked it down.

 

Where did you get your oil pump gear from? Brit Parts of Utah? And how long did it take you? Where you able to slightly drop the front of the oil pan and not remove the whole thing? Did you use a genuine LR front cover gasket or after-market. I have both at hand and they seem of similar quality.

 

Now that I've done it, I'd be comfortable budgeting a day to remove everything and clean things up- and a day to put everything back together.

This being my first time working on that part of this engine, I spent two days pulling everything apart. It took some time to figure out the little things (like having to remove a few extra pulleys to get the front cover out), degreasing everything and referencing RAVE at each step. Putting it back together was far more streamlined. I turned the key with one long day of reassembly.

Unfortunately I had a problem- no oil pressure. Which meant tearing things apart again to trace what was wrong. Thanks to some very bad information, I wasted a two additional days chasing a non-problem and retested it with no improvement. On day three I went with my own instinct and I discovered a broken pick-up tube o-ring, which created vacuum leak to the pump. Once it was replaced I had pressure.

Pointers:
1) Be sure to order a new o-ring for your pick-up tube! I went to Quinn Caterpillar and got what looked like an exact replacement. It caused me a world of grief.

2) Jack the body of the truck up as high as you can get it to create room to remove the sump.

3) Make sure you have a wrench large enough to remove the viscous fan.

4) Using the starter to loosen the crank shaft bolt is great (be careful). I used a block of wood to lock the crank shaft the first time, with a 4 foot breaker bar (simple). 15/16 bolt

5) Mark the water pump bolts. The sizes are specific to a hole.

6) My cover plate to the oil pump was secured with Phillips type screws that have an unusually short groove depth to them. I ground down the tip of a screwdriver to fit the screw and extracted them with ease.

7) There is a camphor on the outer oil pump gear which needs to be oriented to away from the engine.

8) You may want to grab some wire loom material. I discovered many that were simply worthless. I went with a blue color to distinguish ones I've replace from the factory black. Many more to replace.

9) Your front seal may be positioned to the outer portion of the port. I replaced mine per the original installation and it leaked. My crank shaft pulley had a slight groove worn in it. I pushed the seal back into the port a bit so it could seat on a fresh portion of the shaft (no leaks).

10) Take pictures of each step so you can reference back to them.

Enjoy....

 

By my interpenetration, you must remove the pan. The oil pick-up tube (which attaches to the front cover) has a nut and two bolts which can not be reached without removing the sump. Plus the geometry of the pan is such that I doubt tilting the front is even possible. Dropping the pan is simple as long as the truck body is jacked up 4 or five inches.

I got my parts from BA.

I used a LR gasket the first time, but noticed it had a few minor template problems. Some of the bolt holes did not line up correctly and it seemed flimsy- my confidence was not 100%. By the encouragement of two of my flight mechanic friends and an Indy BMW mechanic buddy, I used a liquid gasket product the second time. It took some time to prep the mating parts and apply the bead correctly, but seems secure. No leaks so far.

 

deepblue just curious, is your 03 vin in the death range?

 

I've never looked. From what I've read the defined VIN range of effected vehicles is subjective and extends to 04's.