6.0PSD

So as I get ready to install a new A/F sensor I decided to clean the throttle body/iacv first so that anything that burns off will not hit the new sensor right away and then decided to do an engine oil/filter change...

I had mobil 5000 conventional in there, with about 16oz MMO mixed in... I never pulled a valve cover to see if there is any sludge but decided to run mmo at half dose to see if the placebo effect would kick in... I have been been running quite a bit of different fuel additives over the last few thousand miles and all the placebo effect I got was a lighter wallet, but maybe my fuel tank, valves and pistons did get cleaner but I may never know... I'm currently running 12 gallons of Sunoco ultra 93 with 6oz of Gumout regane and I still don't feel a difference except once again my wallet is lighter...

Anyway, oil is quite dark for less than a 600 mile change... Can all the fuel additives be causing it to darken so quick or is the MMO slowly dissolving sludge that I don't know about? I'll know if sludge is present when I eventually have enough time to start valve gasket change.

Should oil be this dark at such low mileage? Or is it just the nature of the conventional mobil 10w30?

I just went with conventional valvoline 5w30 with 4oz of mmo this time to get through the winter and will see what it looks like in 6 months in which I will then do the valve cover gaskets...

fastnoypi

The coloring may also be the result of detergent additives in your oil choice in addition to fuel dilution from your a/f sensor issue.

6.0PSD

I'll just have to keep a closer eye on it in case it is fuel because of my P0171

99rx

iTrader: (6)

That is pretty dark. I just gave my RX to my grandparents with 110k miles on the clock. I changed the oil every 5k miles and it was never that dark. I always ran Valvoline Full Synthetic and either a K&N oil filter or a purolator pure one. You should really just pull the front valve cover and inspect before you keep throwing fuel additives and oil additives at it. The front valve cover is relatively easy and quick to get off.

Boypony

How many miles on it? Does it use any oil? What year is it? Gen 2 or 3 Valve cover?

6.0PSD

106,800 miles on odometer... I've always used conventional oil since I purchased it @ 82k miles and most oci's were almost always less than 3k miles with only one, maybe two, oci's were closer to 4k miles... At time of the oci's the oil level is always up to the correct level on dipstick so no oil loss issues other than a slight oil leak from hopefully rear valve cover and hope it's not from the rear cam seal... Still running original gen 1 rear valve cover with rubber grommet/pcv valve that with 1999 rx300

Have not had much time to do any more work to it but plan to hopefully soon pull front cover to replace the gasket and tube seals so that I can get a look at what is going on inside with sludge if there is any... The above oil was the result of 598 miles using 10w30 mobil 5000 conventional with about 16oz of mmo mixed in and different expensive fuel additives at every fillup... I'm currently running Valvoline conventional 5w30 and had added about 4oz of mmo at oci and have added another 4oz of mmo about 50 miles ago just about when outside temps here dropped some so not to thin oil too much... Have about 300 miles on the current oil/filter and will change in about another 500 miles or so or sooner if I get to the front cover. Been checking oil every 50 miles and still looks clean on dipstick but have to actually wipe the oil on a clean white paper one of these days to see what it really looks like, I always keeps a dark rag tightly tucked in the engine bay to wipe but can't see actual oil color with it.

Boypony

change valve cover....do a compression check while you're there.

6.0PSD

I don't think I'll be changing the rear cover anytime soon as I don't use this car much and oil level has always been within the limits throughout every oil change... It should be a thing to do for an everyday driver with consumption issues for sure.. My plan is to pressure wash and do a kerosene soaking if needed then pressure wash again until I get a desired clean valve cover... My ocd will tell me when the covers are clean enough to reinstall...

I'll just be happy to get my original covers off and find little or none of the sludge that has plaged many 3.0 owners, then I will squeaky clean my original covers and throw them back on with new gaskets/deals...

I may do a compression test though if I can find the proper way to do it at that time... I'll be researching that next to just clear that out as a possible culprid, but doubt it is my issue...

I'm now leaning more toward bad plugs or possibly clogged injector filters that came from all the cleaners I threw in the tank, over and over again, that may have loosened up crap from tank and wound up at the injector filters... If I drive like an old lady, no offense as there are some old ladies out there that out drive some of the youngsters, well taking it easy it takes time for the fuel eco to get better but I now usually make a couple hard high rpm runs after full warmup and that seems to temporarily fix itself and get that 100mpg on dash after I let off throttle...

One thing at a time for me and may take a few more months but plan on getting it done slowwwwwly with time as I don't really need my car to be in tip top shape right away... But do hope that with my replies it will help someone out one day... If I can take pics while doing some of my work then I do it to show how I did things my way... Will definitely be taking some pics of my valve covers and cams when I eventually pull them...

cwsteini

Oil color alone is meaningless. No one can say if you have an issue simply based on oil color.

Some vehicles darken oil in 100 miles, others in 7,500 miles...

for more info on oil I recommend BobIsTheOilGuy. Best place for all oil related questions.

https://bobistheoilguy.com/forums/ub..._Color_Reveal?

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After multiple washes using pressure washer and engine degreaser foam

6.0PSD

Sitting level and soaking the baffle with diesel fuel...
It's been soaking for about 2 hours now and will let it soak over night...

Wine bottle cork cut down to fit the nipple so valve cover can hold the diesel... Took about a quart to level out as pictured

I slowly added the diesel to the opposite side of oil fill of cover and it slowly made its' way into the baffle until it eventually started coming up through all the tube holes and down toward the fill area... I didn't want to cut the rivets as some do to clean it fully as I don't think I would sleep well knowing that the possibility of a screw coming off and causing a catastrophe... I almost considered it and would have used some red loctite but chickened out... I'm satisfied with how clean it got on the outside... I hit it with the pressure washer through the nipple multiple times and also sprayed the engine foam several times into the nipple which caused it to fill and foam up through the whole baffle

Tomorrow I'll hit it all with carb cleaner and get it all back together...

6.0PSD

All in all the sludge wasn't bad unless previous owner had the front cleaned before... The tube seals were hard as a rock and crumbled apart with a slight tap of the chisel I used...