(Backstory) So as the title suggests I'm considering throwing in the towel on my 03 D2 that I bought back in June as I have too many projects and too little time and money. So backstory, I sold my first D2 for a decent profit back in May and had fun restoring it so when an 04 with 99k miles but a bad engine came up for sale near me I jumped on it. The only problem was that my new engine was going to be in the shop getting rebuilt for probably 2 months at the minimum (shop was majorly backed up and tophatting takes time) and where's the fun in a summer project if you can't work on it during the summer. So I found a 2003 Discovery HSE7 with 135,000 miles and a suspected blown oil pump that had been sitting for 3 years that the owner was selling because they were moving to Belize. Who knows if its true but his story was that the truck was perfect the whole time they owned it and then one day getting off the interstate the oil light came on and would go away if you revved the engine so they parked it with the goal of one day replacing the pump but never getting to it. I had been through a similar situation on my 03 D2 with 245,000 miles before and found the process relatively straight forward so I thought this would be a great little project that I could fix quickly while I waited to work on my other D2. So I opened up the engine and did head gaskets, a new water pump, a serpintine belt, some random pulleys, installed heads with only 99k miles, and the oil pump gears and put everything back together and was unfortunately met with low oil pressure on cold starts. So I drained the oil to put thicker oil in and found copper shavings in the oil and kicked myself for not thinking to do bearings while I had the engine apart, so I opened it up again did bearings and saw improvement in the low oil pressure duration but the problem persisted.

(Issue) So currently the problem is if the engine sits for a few hours and is cold the engine will knock for about 2 seconds before smoothing out as the pressure pumps up. I haven't taken pressure readings yet but I'm looking for any suggestions for what could be the solution to this if there is one besides engine replacement. I've read everything from a sticking oil filter bypass valve to it just being a worn out motor but any suggestions are welcome. The oil light is only on at cold starts and never returns while the engine is warm and running (I know the oil light comes on around 6PSI and I could have low pressure at other times and its just not reporting it so I haven't driven the truck more than a mile in total). I have replaced the pump gear and the front cover didn't appear to be gouged and the gears themselves were not cracked. The junkyard near me has a few 03 D2's out there and I could cheaply try a different front cover on the truck if it's worth it but I'm wary of dumping any more money on the truck.

So if anyone has been through a similar situation your experience would be greatly appreciated, and if you think I should part ways with the truck I'm kind of leaning to at this point as it also needs some brake work and AC work done as well. I really wanted to bring this truck back to it's former glory but at some point I have to stop hemorrhaging money. I know a truck sitting for 3 years was not a good idea but I got distracted by all of the rare options and my dad convincing me it couldn't be that big of an undertaking. Any advice is greatly appreciated, thanks. PFA

 

What weight oil are you using? The oil light being on for a few seconds at startup is considered normal & hearing a little light tapping upon a cold startup wouldn't really concern me as the oil is mainly in the sump. It's once the engine is warm that tapping/knocking, or an oil light would spell serious problems. Like bearings, or the oil pump.

 

The oil were using is 10w40. We were going to use thicker but had some of what’s in it around so went with it. I still worry about it because the engine knocks/rattles pretty good for those 2-3 seconds on cold starts and definitely don’t think this is normal.

 

Like I said it has to pickup the oil from the sump & carry it back up top. 2-3 seconds is nothing. You might try 15/40w or adding some lucas oil stabilizer to help with cold start noise, but if it’s only at a cold start it’s just the oil draining to the sump. Could maybe check your rockers, but in that small time oil has to be pumped back up and 2-3 sec is fine. Anything past 10 sec I’d be worried anything under 5 sec I wouldn’t be concerned. If it did it at every single start yes, but just cold no.

 

I guess. I just have never had a D2 have low oil pressure like this every cold start. I had put oil stabilizer In it after the first time having everything apart and was disappointed to see how it just pooled in the oil pan like glue when I took it back apart. I might try going up in weight and seeing what it does. I may pull the valve covers and see how the rockers look on a cold start.

 

I mean I have 236k on my 02 Kalahari, and after she’s sat a week if crank it you hear a very light tap for 2-3 seconds & then it goes away the second the oil light goes out. Then you never hear it again until it sits for days/weeks. I’ve heard pretty much all engines do that like my I6 4.0’s in my 05 Jeep Wranglers. Slight noise, then silent once the light is out.

Lots of surface to be coated in oil & some will stay up on the valve cover, but not directly on the rockers, rods, or springs. That has to be pumped back up on it once the engine is running and the pump is pumping.

My 97 XD with 168K on it will tap for 5-10 sec then once the oil light goes out the light tapping is gone. I have a new front cover that I will be installing on it because I haven’t owned it for very long and I want to verify the oil pump is good to go. I personally think I’ll just find the engine full of crud from poor oil changes, but better safe vs sorry. I also plan on taking off the valve covers when I slap on some 4 hole Volvo Bosch Fuel Injectors and I plan on removing the rockers and verifying the oil passages in the heads are clean of debris.

#1 important thing is no knocking/tapping while the engine is running, and no oil light on when warm!! That’s when you would certainly have internal issues like a cam bearing, oil pump gear failure, worn main bearings, or worn lifters, cam, bent rods, or bad rockers.

 

As Best mentions, and as the vehicle sat 3 years, and who really knows the previous maintenance history, go to 15w40 and try a detergent oil like Rotella to clean out the internals as much as possible.

 

I've heard similar to what you describe on a few vehicles but on this truck the noise is like the top end isn't getting oil for the first little bit. It's fairly noisy and not what I would consider normal for a short time sitting. I'm going to try upping the oil weight and I might even pull the valve covers off to inspect the rocker arms and to make sure they're getting proper lubrication. Just getting close to throwing in the towel on this one and it kills me to say that.

 

Yeah previous owner acted like they took wonderful care of the truck when it was running right but I dont know that I believe that so much. I ran full synthetic on it the first time I had put it all back together and it was crazy to see how much the oil had cleaned on maybe a mile of driving and a few runs through. I'll think about filling it up with Rotella.

 

How careful with the rockers were you when you did the hg? Two possiblities:

1. You forgot o tighten the rocker bolts fully (I did this once -bled excessive oil out of the bottome of the towers.
2. You mixed it up and the rocker shafts are upside dine, oil hole on top. That will be low oil pressure.