For me 8,000 between oil changes is way too infrequent no matter what oil companies/ car manufacturers claim.

It also gives people an excuse not to check oil levels frequently I think.

Synthetic oils stand up to heat better than natural oil as well as other benefits.

Driving your car around with 1.5 quarts down is in my opinion not a good idea.

You may well have leaky rocker cover gaskets causing the oil leaking down sides of engine.

In checking oil if it is very dark/black it is compromised to some extent at the very least.

Down 1.5 quarts at 8,000 miles may be a bit on the high side but at your mileage maybe not.

 

I'd happily do 8000 mile changes BUT also I check oil levels quite often. Any sign of a shortage and I top it up - immediately!! (I aim for roughly Max rather than Min.)

To be short by so much sounds to be seriously risky.

 

 

2 1/2 US quarts in 8,000 miles ... that's 1,700 miles per Imperial pint ... on a 4.2L (?) eight cylinder engine (remember that's two 2 litre four cyl engines) that's done 200,000 miles ... I'd say that was very good. Assuming you haven't got any leaks then on an engine that size I wouldn't worry until you get down to less 500 per pint (imp) ie 900 per US quart.

 

 

+1 on that.

 

 

 

 

While more frequent changes are certainly good, it doesn't address the cause of blow-by and one of the conditions that happens with the AJ33/AJ34 engines. After about 60k~80k miles, they are prone to carbon build up and need cleaning. Most folks do attempt the intake track side, but seldom do owners take care of the lower end. Newer designs like the AJ engines utilize a lower tension, chrome-flashed ring to not only reduce engine wear, but also reduce internal friction. This does however, leave them susceptible to carbon build up, and certainly becoming glued to the piston by carbon build up. Conventional oil usage, and extended drain intervals only make this condition worse, and the specified oil for the AJ33 was synthetic blend, and not conventional oils. (WSS-M2C913-B) Since the OP does have over 200k, I would again strongly suggest a flush with BG EPR #109, ran for 20~25 minutes after complete engine warm up. (this is required since it's solvent action won't begin until full operating temp is reached) This will unglue the oil control rings so they are free to once again do their job, and free compression rings to once again better control blow-by, the primary reason for heavy oil misting through the PVC, leaving pools of oil in the N/A engines, and contributing to intercooler clogging on supercharged variants.

Who doesn't want less oil consumption, more power and better compression?

 

 

When doing a flush with BG ERP #109 do you fill the engine entirely with the product for the flush?

Thinking of my boat engine here.

 

You add to the oil before change. One 11ounce can per every 4~5 quarts of oil. On a 7~8 quart fill pan they suggest 2 11ounce cans. Drain as quickly as possible, as the suspended carbon will settle if you allow the engine to cool before drain. 109 is a Naphthalene solvent based from standard mineral oil cracking process and it's mixture is very effective and quite safe for all internals, gaskets and rubbers.

 

If you lost 1 1/2 qt then you needed to add some a long time before that!

No way should you be running the engine so short of oil.

 

 

 

 

 

With a high-miles engine as yours is, the oil will be disappearing down the inlet valve guides. There is serious vacuum on the inlet side, plus a lot of oil sloshing around to keep the cams lubricated, so seals are placed on the inlet valve guides to stop oil loss. The seals have to allow a certain amount through to lubricate the guides but not too much. I had a similar problem with my Mazda Xedos 9, but never fixed the problem as I part-exed it for a Rover 75. The old Jaguar XK engines really drank oil until seals were put on the inlet guides. About a point of oil every 200-250 miles !!

So, replace the seals and the oil loss will diminish. Not a simple job, though, you have to lift the heads