As mentioned in the previous update, once I noticed the engine wasn’t happy, I began looking into how bad it was, hoping it was recoverable.
The first thing to do was to drain the old oil and refill. According to the sticker on the windscreen, it was last changed 2 years ago and was due last year by time, not miles.
I idled the engine to get some heat into the oil, and proceeded to drain it. I remember from my last SD1s that you cannot remove the oil filter with an empty sump or you risk draining the oil pump and having it lose its prime.
The oil that came out was really thin for what should be a 20W50 grade. It had a slight metallic sheen, but no glitter and no chunks. It didn’t smell overly like petrol, but it did have a smell to it. It was very black.
I refilled the engine with the cheapest 20W50 I could get that was still a good brand. I found some Nulon on clearance; perfect. It’s not what I would normally run (Penrite HPR30) but there was no point filling the engine with $80 of oil just to see if it was toast or not. $30 oil is more like it.
Once the sump had oil in it again, it was just a case of spinning off the old oil filter and fitting the spare Ryco filter I had in my parts stocks.
Starting the engine, and already it has made a noticeable change. The oil pressure is still scary slow to rise when cold (the light goes out, but it’s many seconds to rise above 0psi on the gauge), but it’s higher on the gauge now.
I did notice that the idle when in gear was lower than it should be (about 400rpm). It still idled nicely, and about where Effie used it, but the lower RPM meant that the oil pressure was bottom of the gauge. I used the idle screw on the throttlebody to bring the idle up a bit. It’s now about 900-1000rpm when at idle in neutral, which is higher than the book says (800rpm), but it means that when the RPM drops in gear, the RPM is still high enough (about 600rpm) that I have oil pressure. It’s a bandaid masking a bigger issue, but it works.
Between the idle bump and the oil change, at idle in gear, when warm, we now have about 16psi of oil pressure, which is a damn sight better than the 8-10psi before.
Which is a damn sight better than what we had
(no I don’t know why the coolant level light is on, I might need to clean the sensors as the system is full)
When revving the engine it goes up to about 30psi at 2000rpm, which is more or less in the ballpark of where it should be (I believe the book says it should be 35psi).
It still clatters though.
The next diagnostic task was to check the exhaust manifold. I had heard that if there is a leak from the manifold that it can sound like a clattering engine knock. Sure enough, a few of the manifold bolts were barely finger tight. I tightened that up, and it still clatters.
I bought a pair of cheap exhaust gaskets and got to work, thinking that maybe the gaskets were blown.
Removing the manifolds was easy enough. All the bolts came out fine since they had recently been loose already. I did note there were no locking tabs fitted to the bolts. Even the downpipe joints came undone easy enough, despite some bodging by a previous owner.
Well, I guess the gaskets aren’t blown then…
They just aren’t fitted
A couple of the ports had traces of sealant on them, but that was it
It was pretty obvious that it had been leaking quite badly. There were carbon traces everywhere.
Using a series of wire brushes both by hand and on the drill, I cleaned up the mating faces of the heads and manifolds. I also had to do some work with the downpipe flange on the manifolds. I cleaned up the threads with a die. One of the flanges had a replacement stud on it, that had less thread. The thread stopped where the arrow is pointing, meaning the nut couldn’t even reach the flange. To compensate, a previous owner had used an oversized nut as a spacer so the actual nut could still tighten down on the thread.
That’s not my style, so I ran a thread down the rest of the stud
The RH side manifold got fitted first. A couple of zip ties through the top bolts holes on either end kept the gasket in place. The gasket was fitted with high temp sealant smeared on both sides, just to aid in sealing. The bolts were fitted with flat and spring washers, to help stop them backing out again.
The other manifold needed the gasket cut in the middle. Since it’s a one-piece gasket, it would interfere with the dipstick tube. It was easy enough to cut out the center piece with some tin snips, making sure to round the razor-sharp corners off a bit
This was also then fitted, with new washers on the bolts and sealant on the ports.
I chose to remove the downpipes so I could clean up the flanges. This turned out to be a PITA.
With the manifolds fitted, and the exhaust still in place, it was a nightmare trying to get these things to fit again. The flange on the manifold isn’t too bad, but the standard joint with the exhaust Y pipe uses a sealing olive and those annoying three bolt clamps to squeeze it together. In hindsight, I would refit the downpipes to the Y pipe before the manifolds, and then fit the manifold with the downpipe loosely bolted to the flange. I wish Rover just used a standard flange and gasket.
As the photo above shows, there are a few oil leaks. It appears that the worst two are the valve cover gaskets, and the sump gasket. Both will be replaced when whatever happens to the engine happens.
So, did that fix it? No. It still clatters, although the engine is noticeably quieter when running now.
The final check I did was the spark plugs. They all look really old, are Champion, and have a weird yellow colour on the ends. Google indicates that the yellow colour is generally due to old and dirty fuel, which would make sense. I put some 98 octane in the car since it came with almost nothing in the tank, and it really woke the engine up and make it run smoother, so I don’t know what the seller put in the tank to load it on the truck.
I had some NGK plugs in my spares, so I swapped all the plugs out for those. I’ve never used Champion plugs, and the internet doesn’t rate them very highly.
So all in all, the engine still clatters. It might be a bit better than it was when I first got the car, more from me masking it with other things than actually fixing it, but it’s still there, intermittently, mainly under acceleration now.
The engine is running better than it has. It can still be a bit grumpy and I’m not sure the EFI system is quite working 100%, but it’s drivable, if you wait until the oil pressure comes up when cold, and can ignore the clattering.
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