[V50_M66]

Alright, I changed the oil today, about 670 miles after the last change. The oil still looked quite clean on the dipstick, but came out black. This tells me that the oil is doing its job to clean the vast amounts of sludge out of the crankcase.

The amount of metal contamination in the filter has vastly reduced since the last change - I really had to look hard to spot any metal, and the metal that was there was much finer than before. This is super encouraging, and tells me that the metal has most likely been in there for a while and isn't something I should be too concerned about.

I changed out the old Quaker State 10W-40 with the recommended 15W-40 Shell Rotella, and I can't believe how much better the engine sounds now. There is basically no ticking under 2,000 RPM now, and the engine sounds much happier in general, with lots of other engine noise now much quieter. It sounds great. That mechanical oil pressure gauge I installed a few months ago acts like a stethoscope, so you hear even the faintest of ticking loud and clear from inside the cabin, but there really isn't any noise below 2 grand (on that note, don't install a mechanical gauge if you can avoid it. After all of the fittings and copper line for my mechanical one, I wasn't too far off from the price of a digital one, which is much quieter, less likely to leak, and easier to install. Learn from my mistakes - go digital). There is still some ticking above 2,000 rpm, but it isn't as loud as it was before. With the slightly heavier weight oil, pressure has increased 1-3 psi across the board as well (it's still on the low side though - 51 cold idle, 9-11 hot idle, 53-54 cold 2k, 37-39 hot 2k). I've only taken it on a short drive to the gas station, but it might make a little more power now as well.
Overall, I'm very happy with the results. I'll keep changing it with the same 15W-40 Rotella, probably with 500-mile intervals. I'm hopeful that the Rotella will help clean out some of the stuff that the cheap oil couldn't, and possibly give me a silent, tick-free engine. Time and miles will tell. I'll report back with any new developments.

 

[reverendALC]

Lol, there’s a D2 for sale near me, the owner states that it was ticking but has subsided since using shell Rotella. What’re the chances

 

[V50_M66]

Lol, there’s a D2 for sale near me, the owner states that it was ticking but has subsided since using shell Rotella. What’re the chances

So it's not just me lol. The stuff works great - I noticed a big difference after only about a minute or so of idling while checking for leaks (major ones anyway - if your LR is not leaking at least a little fluid then it's empty). Still not perfect, but it's only been in there for a few hours and about 20 miles, so I'm hopeful that with time and miles, it will completely get rid of all ticking. We will see.

 

[Richard Gallant]

Cheap oil was always an issue with push rod v8's. Mobil 1 10/30 synthetic and my engine was very quiet but the hot oil pressure was a little low 12-10 psi at 188 -190 at 660 rpm after a road run. I switched to RP 10/40 for summer hot idle is much better 17-14 at 660. On both my cold idle was at 50 - 52 and about 41 at 2000 for the 10/30 and 45-46 for the 10/40. Tested with my temporary digital setup.

Both those oils have the required zinc

 

[V50_M66]

Didn't expect to be updating this thread so soon, but both of my trip-worthy Volvos are currently out of commission for various repairs (fuel pump replacement and suspension work, respectively), so I took the Discovery on an 800-mile road trip over the past few days. Definitely unexpected, but it did quite well - surprisingly, nothing broke, and no new noises popped up. With the engine sitting at roughly 2,400 rpm for hours on the highway, I noticed that the oil heats up quite a bit and pressure drops quite low as the oil thins out from the heat - roughly 27-31 psi at 2300-2500. When not super hot with hours of highway runs, it makes decent pressure - same as usual. By the time the trip was over, the tick was certainly worse than before the trip, even when cold, but still quite a bit better than before switching to Rotella. The oil is definitely cleaning out the junk in the crankcase - it is slightly darker on the stick now, and is probably ready for another change. I'll order up some more Rotella, change the oil again in a week or so, and report back with any new findings.

 

[V50_M66]

In the two weeks or so since I last updated this thread, I have put another 300 miles on the Discovery (1,100 total on the oil). I changed it today. It came out super dark (basically black), so I might have waited a little too long. This is also telling me that the Rotella is doing an excellent job of cleaning everything out.
I noticed that the ticking got louder as I racked up miles on the truck, and right after I changed it, it went right back to how it was right after I changed it with Rotella the first time - basically silent. My thoughts are that this is from more and more sludge being suspended in the oil as I drove it.
The metal contamination in the oil is basically gone as well, with a very small amount of incredibly fine particles in the oil filter. It seems to be making more power after that road trip, which I think helped clean out a bunch of sludge with high oil temperature and RPM for long periods. I'll keep driving it and keep changing the oil regularly with Rotella. It's doing everything it's supposed to, so it's only a matter of time (and oil changes) before the vast amount of sludge gets flushed out and the noises (hopefully) go away.

 

[V50_M66]

In the past 3 weeks, I have put another 900 miles on my Discovery. Oil looks decently dark on the stick - I will change it soon. It isn't ticking as much as it was when I had over 800 miles on the previous Rotella.
Anyway, in those miles, I have noticed that the oil pressure varies a not-insignificant amount with change in throttle position. Holding the truck in a lower gear while going down a hill (around 2000 rpm), I noticed that when off the gas, the pressure reading on the gauge jumps 4-7 psi. If I touch the gas, the pressure drops. Let off, and the pressure jumps back up. This always changes the same amount, whether I am barely on the gas or full throttle. I can't think of a good reason why this would happen, but at 2,000 rpm when going down a hill (applying no gas), my oil pressure is reading more like 43 psi instead of 37. This makes me optimistic that my oil pressure is actually better than it usually shows, but I am also unsure of why this would happen. It may be a byproduct of connecting the gauge to the top port where the oil cooler would hook to if my truck had one. I don't know. I'd like to think it's nothing that would impact it, but it is strange so I figured I'd mention it.
Other than that, the engine still lightly ticks, but runs great otherwise - it makes great power and easily cruises at 75-80 on the highway, even on 32" tires. I'll keep driving it, keep changing the oil, and post with any new developments.

 

[V50_M66]

Update for anyone that cares.
Haven't changed the oil yet because I have parked the truck due to multiple bad spark plug wires (sparking through the insulation to the block, causing misfire codes). Doing this job looks like a nightmare, and since I have to take the upper intake manifold off to do it, I might as well pull the valve covers and have a look (and maybe clean it out if it looks bad). I'll change the oil at the same time, and report back with pictures of the valvetrain and anything new that pops up.

 

[V50_M66]

With the intake off to do the spark plug leads, I decided to pull the valve covers. Pulled the driver-side valve cover today to have a look at the rockers and valve springs. Honestly, it looks quite a bit better than I thought, with far less sludge than I was expecting:

It's obviously far from perfect, but isn't totally caked with sludge, which is what I was expecting. The back side of the valve cover had a good bit of sludge built up on it, so a gave it a quick soak in gasoline to clean it out.
Before:

After:

Put it back together at the end of the day with a new gasket, as it was leaking heavily before. Ran out of daylight after the one side, so I will do the other side tomorrow if it I have enough time, and post some more pictures if that side looks any different, or if anything significant comes up.

 

[V50_M66]

Didn't have enough time (or enough coolant) to drain the cooling system to get access to take off the passenger side valve cover, so it stayed on. Got the truck back together after changing out the plugs and wires - it sounds like a new motor now, aside from the light ticking and a small exhaust leak. Changed the oil after roughly 1,000 miles - the oil was as black as the plastic pan it was going into. Seems like there is still a good amount of sludge getting cleaned out. No metal in the oil filter, so I think I can safely say that was built up from years of neglect.
I'll keep updating this thread as needed with any new progress or updates.

 

[V50_M66]

Took a quick video of what the engine sounds like now. It is certainly better, but not totally gone (the rattle at idle is a loose heat shield).

Just for comparison, here is the original video I took before all of the oil changes, Rotella, etc:

While still not perfect, it is certainly a distinct improvement. Hopefully it will continue to get better.

 

[V50_M66]

I have the engine completely torn apart right now to do head gaskets and figured I would take everything apart to inspect, clean, and do preventative maintenance. I took the front cover off to look at the oil pump, and it’s still in one piece and seems to be operating fine. I will be putting a new one in just in case. However, I pulled the oil pan to pull the pickup tube off to take off the front cover and what I found was shocking.

Yep, that’s the oil pickup, absolutely packed full of crap.The valley gasket/lower intake gasket has a coating on it, and that coating was starting to separate and fall off in chunks on top of the lifters and cam, and eventually worked its way to the oil pan. This is the amount of junk I pulled out of it:

So that’s probably where my slightly low oil pressure was coming from. In other news, I will also be replacing the lifters while the engine is apart so hopefully that will take care of the ticking for good. I’ll keep updating with new developments.

 

[V50_M66]

I’m happy to report that the ticking is completely gone after replacing the lifters (and head gaskets, water pump, oil pump, timing chain, radiator, front main seal, and giving everything a thorough cleaning, but I’m 99% sure it was the lifters). I can’t believe how smooth and quiet it is now. I haven’t taken it for a drive yet (it started getting a little hot - 206 just idling - I’m assuming the thermostat broke when it overheated the first time when it blew, because the bottom hose was still ice cold), but it’s almost perfect. It sounded like a diesel when I first started it, but after a few minutes everything smoothed right out and it sounds amazing. I’ll report back if anything changes, but I’m very happy with the lack of noise now.

 

[V50_M66]

Turned out I didn’t need a new thermostat - I needed to bleed the system properly. Hold the revs high once it hits 185 or so while undoing the bleed screw until the heat works and all the air is out. Just a heads up for anyone else that gets confused, and then wastes a bunch of time and money taking the cooling system apart twice (also, the 180 thermostat FCPEuro has is actually a 190, so the cooling system came apart a third time to put the old and perfectly fine Bearmach 180 back in).

Anyway, I got a video of it running today. The audio is a little different because I got a new phone since then, but the engine sounds perfect with no ticking, which I’m very happy about.

 

[tyl604]

Any idea what sludged up the engine so badly? I have never seen one look that grunged up.

 

[Richard Gallant]

@tyl604 it is almost always long periods between oil changes and of course higher temps. You will start getting varnishing and then sludge build up.

 

[V50_M66]

I don’t think the previous owner ever changed the oil, and put all sorts of other stuff in the oil fill (it was overfilled and muddy brown when I got it, and didn’t smell like oil). It was also used as an around-town car before I got it (the po used it for dump runs and stuff for the last few years from what I heard, so it probably experienced the horrible combination of the coolant always being too hot combined with the oil never getting fully up to temp) and it was super neglected for years. I have a picture I forgot to post of the oil pan when I had it off - there was a good two or three inches of sludge built up around the bottom.

That was from a few days ago, after 9 months and 3,000 miles of cleaning with 500-800 mile oil change intervals. It was almost certainly far worse when I got it. A 180 t-stat and frequent oil changes, as well as plentiful preventative maintenance, are the key to longevity for these things imo. Mine no longer ticks, and runs super smoothly, so I’m happy with it. I’ll change the oil super soon to flush out any remaining coolant/oil combo from when the head gasket blew. It still leaks oil from the front main seal (replaced it again - same issue), and it weeps coolant from a water pump bolt, but other than that, the engine is set. Hopefully the damage from the previous owner won’t cause any more failures.

 

[Landybobandy]

Thank you for your extensive write up! I will take a lot of the tips you and the other suggested and see if I can rid the tick inside my disco.

 

[masantschi]

So, on your front main seal, did you replace that with a LR Genuine?

I put a new front cover on mine and it had a brand new Crank Seal in it - and it leaked. I bought the LR Genuine and installed that and no more leak. You could obviously tell the difference between the 2 when comparing side-by-side.

If you have a LR Genuine in there and are still getting a leak, you're going to need to pull that Harmonic Balancer and check for a groove in it. It could need a sleeve on it, or you can pick up a used one with less wear for $50-$100.

 

[V50_M66]

So, on your front main seal, did you replace that with a LR Genuine?

I put a new front cover on mine and it had a brand new Crank Seal in it - and it leaked. I bought the LR Genuine and installed that and no more leak. You could obviously tell the difference between the 2 when comparing side-by-side.

If you have a LR Genuine in there and are still getting a leak, you're going to need to pull that Harmonic Balancer and check for a groove in it. It could need a sleeve on it, or you can pick up a used one with less wear for $50-$100.

Thanks for the advice. I replaced it a second time and same issue, so I started looking closer. Turns out it was actually the connection for my mechanical oil pressure gauge, which was leaking quite heavily down into the same general area. I hit the threads with some Teflon tape and no more leaks.