V8-Ranger.com

Thought you guys might find this interesting. A friend of mine purchased a used RX300 with about 120k miles. It's in great shape and runs like a champ. I changed the oil for her when she got it and put Mobil 1 full synthetic in it. About 5k miles later she calls me up and says the oil light is on and the engine is making a ticking noise. Should she pull off the highway or can she drive home? lol I told her to pull off and shut it down right away. I came out and checked the oil level and it was full. Fired it up and it was fine, no oil light. So I proceeded to drive it to my place as it was very close by. I noticed it was really starving for oil. After about 5 min of running the oil light would get flicker at idle and eventually just stay on.

I dropped the oil pan and found the worst case of engine sludge I've ever seen. The oil pan was over half an inch thick in sludge and a lot of it was baked and caked on so hard I had to use a screw driver to chip it up and off. Looking up into the engine after the oil pan was pulled was amazing. I've never seen anything like it. The whole job took me about 3 hours because there was so much garbage caked on everywhere.
The pickup tube I soaked in solvent and used the air compressor and blew out so much. That screen was so packed you couldn't even tell there was a screen in there initially. It was so clogged that's why it was starving for oil.

My theory is the prior owner never changed the oil or hardly ever I'm guessing and when I put in Mobil 1 full syn the detergents started cleaning up the motor and broke loose all that sludge and clogged it up. After cleaning it all out it runs like a champ. I told her we should probably change the oil a little more frequently till we get all that garbage out the engine. I may drop the pan again in a few months too and see how it's doing.

Here's the oil pan half way though cleaning it
Inside of the engine

That was a nasty mess.

Yeah unreal. Can't believe how crappy it was taken care of.

Yes Malcolm that is from probably no oil changes. When I was in the dealerships we would have a similar problem. The engine would get so sludged up that the drain holes would get plugged or dang near plugged. After the engine had sat there awhile you could start them and all was fine, within one minute the light was on, you could shut off engine and check oil and there would be no oil in the engine. Wait about 15-30 minutes then check and the level was fine. The oil pump would pump all the oil up top but it couldn't drain back fast enough to keep pan full. Had one where it was completely plugged, they kept adding oil cause it would check low. When I pulled valve cover off about a quart and a half poured out both sides. I had to pull engine remove intake, heads, pan and so on and just pressure wash the engine, dry and reassemble. Had a friend who worked at the chevy dealership took a picture of one he had, when he pulled the valve cover off it looked like the V/C was still on, the sludge was so bad it was formed like a mold to the V/C, you could read chevrolet across the sludge. It was unreal. I did at least 10 engines a year like that, just blew my mind the money people spend on these cars then don't take care of them.

my wife blew up her dodge caravan by NOT changing the oil.. just like that.... i had been paying for oil changes that the van NEVER got.... so one day she called me with the same problem... so i went and took a look at it ... and it showed full .... so i fired it up.... no oil light and plenty of oil pressure.... after about 5 to 8 mins of running... the pressure started to drop and the light came on .. so i shut it down and drained the oil ... to be sure... it had like 4 quarts in it.. so i put it all back in.. an a new filter.... then i noticed.... it was the SAME oil filter i put on over a year and a half ago .... anyway... fired it back off... and .... same problem... so i dropped the pan... the WHOLE sump was FULL of sludge... i mean the oil was sitting on top of it.. and the oil pump had sucked a tunnel to the top to get oil.. man i threw a fit !!!!!!!!! .... and lo and behold.. got it all cleaned out and put back together..... filled it back up and fired it off... and it started knocking about 3 mins later.... so she killed it.... and i laid in on her about it ... now... she gets oil changes every 3000 miles !!....lol... plus it cost her to get a new car ..... not me.... her !!!

When I was working as a mechanic, I only had 1 experience with bad sludge like that in a customer's car. I remember it was some really crappy POS Chevy I think that the oil filter was actually inside the oil pan. The oil pan had a standard bolt that you pull to drain it, then a bolt that was about 4" in diameter that you pull to get access to the filter element. I only remember the incident because of how unique this car was to change the filter. I never saw another car come in like it. Anyway when I drained it, the oil came out pitch black and in clumps. I pulled that big bolt to get to the filter and the filter was completely coated in sludge with sludge all over that plate-of-a-bolt. With the filter out of the way, I could get my fingers into the oil pan and remove sludge like what Malcolm's showing. There was gelatinous sludge everywhere. I got out as much as I could, but I'm sure the engine was just going to clog the new filter as soon as I put new oil into it. I told the owner. They were surprised and acted as though they had regular oil changes and that this shouldn't have been the case. My gut feeling is a wife was "claiming" to be taking the car in when she was just skipping it.

I'd heard of people running Quaker State back in the 70s and 80s when they used parafin in their oil that would get sludge buildup really bad such that the valve covers could be removed and it looked like the cover was still there although I've never seen that for myself. The good news is even the cheapest of cheap oil today is of a high enough grade and quality that it requires absolute neglect to get this to happen in today's engines. Oil standards are about like gasoline standards...there's very little difference between the cheap brands and the name brands of conventional oils anymore. In fact, most of the cheap brands are buying from the same refineries that make the name brands with the only differences being a detergent here and there. There are still quite a bit of differences between the various synthetic oils though. Although ALL of the synthetics are better than any brand of the conventional oil. So buying anything more than the cheapest synthetic for a normal duty car is probably overkill. But for industrial or racing applications, there are significant differences in synthetic grades with Royal Purple and AMSOil being the best of the best for racing applications.

Wow lifting a valve cover and it looks like its still there is crazy. I imagine this RX300 might be something like that. I noticed when I remove the oil fill cap it's all crusted around there too. Hopefully a few oil changes later this thing will start clearing out. My engines always look brand new inside when I open them up even with almost 200k miles. Amazing what such simple little maintenance does for the engine.

You may even want to run a quart or two of kerosene into the oil for a few minutes (engine in neutral only) before you do the next oil change to further loosen some of the clumps before dumping the oil you just put in there.

And of course, I would be using the cheapest oil you can find from now on for at least the next 3-4 oil changes. There's little reason in wasting the money on Mobil1 for an engine like that. Ever since I've known I'd be swapping my engine for the 331, I haven't been wanting to use synthetic oil in my engine. So I got to looking around for the cheapest oil & filter when I knew an oil change was coming up. I was amazed that the AutoZone, Advance, and Walmart brand are often NOT the cheapest you can get. The last oil change I did, I found the cheapest oil at Target...Mobil (standard) 5w-30 for $2 something/qt a few months ago. The price has gone up last I looked. Then I saw an advertisement at AutoZone for a 5.25 qt jug of Peak brand on sale for much cheaper than I could get plain oil by the jug or quart anywhere else. Of course if you are needing oil NOW, it probably doesn't save to go burning gas looking for whose got the cheapest. But if you are out-n-about and an oil change is a month or two away, it's nice to keep a mental idea of where has the cheapest oil. And for a beater engine like this, whatever you pour down it is getting mucked up with sludge contaminant so it really doesn't matter.

Not sure about the kerosene and I don't keep any around but they do have something similar at the autoparts store I've used in the past on a similar sludge situation but it wasn't as bad. It's a petroleum based product that just breaks down oil. I forget the name. You pour it in and let the car idle for 10 minutes (don't drive it) and then drain it out and put fresh oil in. Take a drive and drain it and put fresh oil in again to make sure it's all out.

Yeah I probably won't have her putting in full syn just to dump in a 1k miles for a few times. That night though I had to dig into my stash in the garage to get her running again and mobil 1 full syn is pretty much all I keep in my garage. Probably not a bad idea with cold morning cranks and snow on the ground.

I'd like to do a few oil changes about 1k apart or however it works out and then drop that oil pan again and see the condition. I'm curious as to whether some frequent oil changes will clean that out on their own or not.

cgrey ,,,,,,,,
I remember it was some really crappy POS Chevy I think that the oil filter was actually inside the oil pan. The oil pan had a standard bolt that you pull to drain it, then a bolt that was about 4" in diameter that you pull to get access to the filter element. I only remember the incident because of how unique this car was to change the filter.

my dad had a 94 or so Chevy Celebrity that was like that.... i HATED to change the oil in that ragged POS .....

and Malcolm ... i have done sorta like you are sayin with the kerosene... but use diesel fuel .. it will cut every bit of the old sludge ... just drain the oil... put on a new filter.... and add like 1 to 2 gallons of diesel an start it up.. let it idle for like 10 mins or so.... then drain it... and do it once more.... then just add a new filter and new oil and take it for a drive.... do it again in like 100 to 200 miles... and that should be all ya need to do.... i have had to do that to a few vehicles i have worked on and it does work.... well to a point... ya can never get ALL the sludge out without a tear down and rebuild ........ but good luck... and remember when ya got the kerosene or diesel in it... DO NOT drive it or get it over like 2000 rpm ... thats about the same as not removing the sludge at all .....lol ... anyway .. GL an keep us posted .....

Peace

Marvel Mystery Oil. I've heard ATF works good too. Theres a lot more detergent in ATF than in motor oil. Add like a quart. Keep in mind everything that comes loose from the top end will end up back in the pan and into the pick-up screen.

Malcolm
You may want to check on the sludge problem Toyota has had on several models. If I remember right the crankcase vent system was very inadequate. A friend of mine had a toyota van that the dealer had done all his oil changes and at abour 80K the engine was so full of sludge it finally just died. The only way he got new engine was due to the dealer doing the oil changes. This problem has been kept very quiet. http://www.consumeraffairs.com/news04/2 ... ement.html

87sc302 wrote:Malcolm
You may want to check on the sludge problem Toyota has had on several models. If I remember right the crankcase vent system was very inadequate. A friend of mine had a toyota van that the dealer had done all his oil changes and at abour 80K the engine was so full of sludge it finally just died. The only way he got new engine was due to the dealer doing the oil changes. This problem has been kept very quiet. http://www.consumeraffairs.com/news04/2 ... ement.html

Oh man. What a story. Her car is in that list they show there too. Wow so basically the problem is not going to go away. Are there any fixes to the problem?

Not to get side tracked but this brings up an important issue on another project car I'm almost finished building. It's a 98 Civic turbo car I've built. Because of the turbo pressurizing the intake manifold I've removed the traditional PCV system and just have a hose running to a catch can. Two hoses, one from the block and a second from the valve cover. Gives it good breathing room so pressure doesn't build up in the block when under boost from blow by. However in normal cruise there is nothing drawing air through the block and out. To me this sounds like a sludge problem coming up but others that have done this on the Honda forums say no they're fine. No sludge, I have my doubts though.

The only fix I know of is a new engine, at least that was what Toyota was doing.It is amazing how this problem was kept quiet.
Toyota denied they had a problem for several years.

Crank case venting can be problem a with many engine configurations especially high rpm and turbo/supercharged engines.

All the links I read say don't put any engine flush in there as the oil return passages are so small in that motor you'll clog them up as stuff comes loose. I also read that Toyota made the water passages in the heads smaller so they run much hotter to reduce emissions however the 60F or so temp difference between the heads and the block cause sludge as the oil passes. Man what a bummer. Apparently full synthetic is less prone to sludging so her best bet at this time is to run full synthetic and change her oil frequently from everything I've googled so far. I'll also check and replace her PCV valve in case it's clogged but not hanging on to that as a fix.