Mystery oil loss and Oil separator

[johnyrover]

Good evening gents.:)

Well I'm slowly getting through Her Majesty's essential services. Oils and fluids just about done. Just the brake fluid and an auto trans service to go. Woo hoo!
So far so good, had her 3 and half months, done 10,000ks, -I bought it to drive it - and no major dramas so far. (I dont count swapping the EAS for coils, that just had to be done.)
Except.
Went for a 1200k trip about 2 weeks ago, and when I got home she had drank about 800ml of oil. I checked the oil just before the home stretch -500ks- and it was down just a bit from the top. Previous to this usage had been about 200ml over the 3500k's since the first oil change. There was more oil than usual under the engine and it looked like it was seeping from everywhere.
I have since changed the oil and filter for the second time since ownership, and cleaned the motor. The old oil was darker than the dipstick colour led me to believe. I have isolated a couple of slow leaks that dont even drip once the engine is shut off. One is a join in the short oil cooler line (have ordered new one) and the other is at the rear of the sump (also to be resealed soon). The strange thing is I have done about 600ks since changing the oil and filter and the level has barely dropped at all.
My initial thoughts are that the oil filter was so blocked that it was pressurising the engine. I know it is supposed to have a pressure bypass but nothing else fits.
The other thing is I have tried to find out whether my model - 97 HSE 4.6 should have an oil separator in the rocker cover. At the moment the metal tube is empty and clear.

Hope you enjoyed this novella.:p

Any thoughts and input greatly appreciated. Cheers :D

[wayneg]

Good evening gents.:)


My initial thoughts are that the oil filter was so blocked that it was pressurising the engine. I know it is supposed to have a pressure bypass but nothing else fits.


Not sure what you mean by this, Myself and some others use generic Z9 filters with no issues at $5 to $7 a pop. If you dont change the oil and filter very frequently you are asking for trouble.
I would also think about a thicker oil. Lots of opinion on oil type but for me we dont need low viscosity in Australia so 10 or 15w are out. Good old 20/50 does it for me. And if it does not drip a bit of oil now and again it ain`t a Land Rover

[johnyrover]

By nothing else fits I meant causes. I use z9 as well. I change the filter with the oil every 5000ks. The only mistake I made was trusting the dealer when he said he had done it not long before I bought it. That oil was black black black when I dropped it. Also it ran like water when I let it out.
I was toying with the idea of a thicker oil but wasn't sure what sort of life the motor had had or how much pressure to put it under at first. It was 190,000 on the clock when I got it. I currently use 10W30 and thought of going up to a 40 next change so I will consider your advice of 20W50 on that one.

Thanks Wayne.:D

[Keithy P38]

50 weight oil is borderline for winter in a P38. The tolerances for an oil that heavy would be similar to a Holden red 6 or something made in the late 70's/early 80's!

If you've used a 30 weight, try a 40, if you are still using oil then and changing again to a 50 fixes it, you may have valve seals or piston ring issues which you are masking.

No offence intended to you Wayne. It was an old car dealer trick back in the day to put a 60 weight oil in an engine that used a bit during warranty periods!

Cheers
Keithy

[benji]

A blocked oil filter cant pressurise the engine. Oil goes from the pump, past the over pressure valve, through the cooler, oil filter, then into the block.
Its a common mistake to overtighten the oil pipe unions, which makes them leak.

Your 97 will have an oil seperator on the rh rocker cover.

With Bright being a tad cold in winter I'd be going a 10w40. Or even 5w40 if you can find it in a mineral oil.

[johnyrover]

Found the oil separator. I had looked at the RH rocker cover twice before, but in the sunlight the breather hose nearly bit me. Feel a bit silly there. It's not blocked so that's cool. Going up in stages with the oil makes sense thanks Keithy, so if I have to 40 is my next stop. The rig is running pretty sweet though so if I dont have to change I wont. Maybe thicker for summer? I did screw the oil hoses back a bit and re-nipped them due to the warning in RAVE. It actually stopped one leaking but the other one leaks at the bottom of the metal join on the RH hose near the cooler. Thanks for the lesson on oil circulation benji, much appreciated. So I can rule that out.
Which brings me to valve seals and rings. I know the usual symtom of smoke with both of these, but is it true that cat converters can trap that before it leaves the exhaust? And even if that is the case the amount of oil I lost should be at least a bit evident out the exhaust. Currently there is none at all. Is there any way to assess the condtion of the seals? Is a pressure test the way to go for the rings?
Like I said its got me buggered why its not using oil now, unless the other oil hose was leaking more than I realized and stopped once I played with it.

As usual any advice/info would be graciously accepted.

Cheers.:D

[wanglemoose]

regardless of what brand or weight of oil you use as it gets closer to a service it can start to consume oil. depending on weight and brand will change the time it takes to start burning it. as oil gets old and with the contaminants from engine running it looses its viscosity and fails to do its job, causing oil use and higher wear on the engine. now this next bit comes from the oil rep that supplies my mates shop, keeping in mind that he deals in all brands of oils. " No oil is designed to last more than 7500 k's, it breaks down and is useless after this point" the reason manufacturers have longer service intervals is that if they only service the car 5 times in 100 000 k then its made its warranty period. they dont care that the engine might be worn to the point of exploding at 100 001 k's, as after that you need to buy a new car. Also it is a common misconception that an engine using oil is a bad thing, 1 liter of oil used over a 5000k service period does not mean your engine is stuffed, the more places the oil makes it inside your engine the less wear there will be even if this causes a small amount of oil use. valve stem seals for instance, a lot of performance engines do not run them as they wipe the oil from the valve stem leaving the stem dry and causing a shorter life of the stem and guide, generally a standard engine will run them as the pressures on the valves are not enough to see a great difference in life to the stem or guide. And as always if its not leaking oil then its not a rover.

[johnyrover]

Now up to about 800k's after its second oil change (mostly highway ) and still only slight drips, not even dropping on the dipstick. It is a lot drier underneath, so what you are saying about the oil getting thinner and leaking/getting used easier the older it gets is ringing true for this instance. 1 litre used per 5000k's was about right, it was just that the last 700ml or so dissapeared within about the last 1000k's, and it looked like most of it ended up under the car. The auto trans pan was definatley not that oily when I first got it.

As usual thanks for the input. The longer I own this beast the better I feel about it, but it does not hurt to keep on top of potential problems in a car this old.

Cheers.:D

[johnyrover]

Finally got around to taking Her Majesty to a Rover Mechanic. Turns out the valley gasket is leaking in a couple of places. So one mystery solved, and not too serious.
Cheers:)