Some random thoughts

- Removing the plug allows an extra 1/8 quart to be drained. Drain plugs and oil pans are rarely configured to allow 100% of the old oil to drain. How much more is still left behind?

- What is actually contained in the 1/8 qt? Might be fun to analyze it.

- Even if the engine is now 100% drained, the really nasty goo being discussed is still sitting on the bottom of the pan. It isn't viscous enough to flow towards the drain under gravity.

- If the goo won't flow it won't harm the engine. An analogy is the hokey 'duct cleaning services' for homes with forced air heating and AC systems. If the stuff is just sitting there it isn't floating around doing harm.

- How come the oil pumps on engines do not suffer premature damage since they only see unfiltered oil?

 

This is just from what I seen..no opinion, no conjecture, no editorial...


-->The plug as I remember is in the side of the lowest point of the sump pan..The Sump pan was like in two levels and stepped down to a very small area at the very bottom where the plug was..i could stick my little finger in the hole and feel the bottom was empty other than a black film of oil...I would have loved to flush it out with some denatured alcohol..



-->Oil pumps are pretty robust and have looser tolerances than say the main bearings of the crank...but after that, who knows how much extra wear is on the pump because it's picking up un-filtered oil..?

 

Oil pumps actually do wear but they are very simple devices which work very well even when worn. The oil pump is capable of pumping far in excess of the required quantity even when worn. Obviously they are not a pressure pump but merely a volume pump.

The oil returning to the sump isn't particularly contaminated by particulates anyway and certainly not large enough to cause a problem with the oil pump. There is a strainer on the oil pump pick up which keeps large particles in the sump. The pick up is above the bottom of the sump anyway.

The excess volume of oil in the sump is mainly for cooling purposes. Engines do not need to be run at the "full" or "Max" mark. There's plenty of excess oil doing nothing.

 

I like Jagular comments and yes I agree with what others say about his comments. It makes reading the forums interesting and funny

 

Again your lack of direct knowledge and experience in the field betrays you. The long term function of a gear pump requires a supply of clean, contaminant free oil, no different than any other plain bearing surface. Defects in the tooth surface caused by contamination will quickly lead to failure of the unit and possibly the entire engine if not caught quickly.

 

Mikey:
Although I have seen a gooey deposit on all surfaces in an engine, I do not get the impression that the last bit of oil that drips out of the drain is any more viscous or contaminated than the rest of the drained oil. I will even admit that I have removed the lower sump on my XJR on the first oil change after my head gasket replacement to wipe the inside since the engine was open for about a year and I was concerned that contaminants might be in there! What I actually wiped up was some bits that looked like they might be small chunks of chain tensioner rails.

So, your other question of how much is left after a plug drain and the notation above both indicate that the most "careful" among us should remove the sump and wipe out the bottom with a rag! ( yes, I am kidding for the folks without humor)


Also, I have been into the engine on my wife's XJ8 after 175,000 miles of full synthetic oil changed every 10,000 miles or so and seen no goo, and no sludge, only a brown - red "patina" on all surfaces. I would hope that in a Jaguar engine the only contaminant that we should wory about going through the oil pump would be tensioner wear particles. We are talking about engines, not rock crushers.

 

All that you said is true, but (It pains me to admit it, but Jagular is also correct in some that he said)... Oil Pumps that I've seen or replaced were damaged mostly because of LACK OF OIL flow, meaning the engine ran low due to a lost oil plug or simple consumption of oil and cavitated the pump..this is serious wear and will destroy any oil pump..As far as contaminates, there would have to be a lot and large particles to do any serious damage to where it stopped producing oil pressure to feed the engine (idiot lights are just that, that's why I wish we had gauges)..I hope no JAG owner would ever let their engines get to this point.

 

I agree, but how often to we read tales of woe on the forum about how there was a cloud of smoke or steam or a light came on and it was only a few miles to get home.........

 

Yeah, and, the fact is, many times folks make it home OK, so they try it again, and again!

 

I heard ghastly tales of Owner's of Jags and Benz's when I had one of them, that these give-a-**** owners would basically drive their cars until something failed..usually the engine due to lack of coolant or oil They never did a thing to the car except drive it till it died....UUUUGH...Boy I wish I had that kind of money to have such a give-a-**** attitude.

 

This is incorrect. Oil pumps are very tolerant devices and continue to be capable of delivering more oil than the engine requires even if very worn. You need to understand how they work to realize why this is so.

 

You got to be kidding .

 

I do.

They do supply more than required- right up to the moment they-self destruct from contamination. You'd know that if your experience went beyond Google searches.

 

When I had my first oil change in my 5.0 f-type the oil extractor didn't suck all the oil yet the highly trained technicians went ahead and stuck 8 U.S. quarts back in. The result was that I had to correct the situation afterwards. I found it was overfilled by almost two quarts. So a lot more than four ounces was in my pan before the oil was added in. I figure the total oil left before oil was added at over two quarts.

I have now had a second oil change at a different dealer and this time the overfill was closer to a half a quart. Again, I used my extractor to check. Again, as before, the invoice said 8 quarts was added back in. So this time maybe almost all the oil that could be extracted was. Still not all of it though.

Had either tech used the oil drain instead of the extractor, addIng 8 quarts would have been less of a problem. Neither tech put back in the same amount as was extracted.

My thoughts on this thread are that most of you don't know how much oil was left in your engines before oil was added in unless you personally used an extractor to find out. Also, the crap at the bottom of the pan cannot be removed unless you drop the pan and wipe it out with a rag.

 

Nookieman:
How did you determine the engine was overfilled? Did you check it on a hunch, or was there some indication?

 

These engines use an electronic dipstick. If it shows engine oil level is OK then it's OK.

Upon checking the online handbook an oil and filter change requires approximately 7.25 litres which is 7.7 quarts. If you had 8 put in that is correct, or near enough.

Elsewhere I suggested 6.5 litres is the correct amount but that was for the older. 4.2 and 3.0 Duratec V6. The new engine takes very nearly 8 quarts.

I too am curious how you could be so sure you extracted 8 quarts rather than 7.7 quarts.