What happens when an engine has been run with oil for a long time, so long it looks like mud when removed from the oil pan, and then the engine is given fresh, oil to use instead?

 

There are so many details left out of your "question", it's hard to say whether you just saved an engine from near death, or are just trying to start a flame war.

 

some minor details edited out to avoid flame war and general misinformation. the few words removed have little or no bearing on any answeres given.

 

Approach the subject logically.

You come across an engine whose oil looks like mud. Now, let's look carefully at all possible courses of action, and decide which one is best.

Your options are:

• Leave the oil that looks like mud in the engine; or
• Change the oil

Which one would be better for the engine?

You won't damage the engine somehow by replacing the used-up oil. Whatever damage there is, has already been done. All you can do now is either make it worse by leaving the old stuff in, or supply functional lubricant.

Doesn't seem like too hard of a choice to me.

 

Okay, here's the deal. I knew the engine was in dire need of an oil change, so I went from whatever "mud" was in there to a rather thick fossil oil. I've been using fossil oils ever since then, but the engine doesn't seem to be lubed properly when it gets to operating temp.
And no, I'm not trying to start a flame war, I'm just wondering if it was good for the bearings to go straight from synthetic, if that was what the "mud" was, to fossil oil, or to step down gradually as in the reverse of how you are supposed to switch over to synthetic if you have never used it in you engine.

 

it doesnt matter.


if it looked like mud, the engines screwed anyway.. put some good oil in there....

if it was really bad, id change the new oil again after 500-1000 miles or so... just cause it probly loosened and picked up alot of the crud that the old oil left in there.


other then that, thats the only thing id do diffrently

 

the condition of the engine is questionable so you can risk a couple of differant fixes and see what you end up with. might want to think about some sort of internal engine cleaner, run a quart of ATF for a hundred or so miles before you change oil, run synthetic since it tends to clean the internals a bit.

 

yea... marval mystery oil would be my personal choice, but yea, running somthing to clean it out right before you change it isnt a bad idea either..

 

okay, maybe i was exaggerating the condition of the old oil when I removed it, but it looked like it had been in there for quite a while. I have used a couple of additives to try to keep the oil thick at higher temps, but without much avail since I was adjusting the valves at the time. Also, when I removed the intake to check to see if the lifters were okay and change the gaskets, I noticed a butt load of crud in there that I removed with degreaser and a brass-bristled brush.

 

Ah HA!

Viscosity-enhancing additives!

That means polymers. Polymers = sludge as soon as the oil heats. Excessive polymers (from additives or poor quality engine oil formulations) mean excessive sludge.

That help clear anything up for you?

Additives? Don't even....

 

Well, what else am I supposed to do when the oil heats up pretty hot becuase my air dam ain't worth beans and my coolant temp is over 220, almost to redline? And the crust I am talking about I removed LONG BEFORE I even thought of the polymer additives, and the very old oil was removed LONG BEFORE that.
And for further reference, it will be roughly two weeks before I get a working ECM so I can start work on the car inside the garage, where I will be doing a complete tune-up.

 

You're supposed to fix the air dam. That is NOT overheating. The factory fan switch doesn't even turn on the fan until the coolant temp reaches about 230 degrees!! That means the factory thinks that the engine doesn't even start to need cooling until that temp. There's absolutely nothing destructive about 220 degrees. The correct answer certainly isn't to artificially thicken the oil.

Use the ATF trick to clean out the sludge. Run one quart of it in the oil for 500 miles or so, and change the oil; use a quart in the next oil fill; and keep using a quart of it in the oil until it quits coming out thick and black. Quit using "thickening" additives, they do far more harm than good. And fix the air dam.

 

I have four of the five pieces of the air dam installed, but, supposedly, I have to have the large piece that attaches to the front clip and runs in front of the radiator itself. And I know what the engine fan temp is, but it likes to run way higher than that, like I said, almost to redline (when I say almost at redline, I mean ALMOST AT REDLINE!). I also have installed a lower temp fan switch which I have to reinstall since I used teflon tape on (coolant passage don't need sealant? Weird...), and that didn't seem to help much. Of course, the car has not left the driveway since I installed the air dam pieces (damn ECM... If I only had a gun, I'd put it out of its misery), plus the fact that the temp outside is lower than it was before the dam went on, and running in the winter is no problem at all, so I just want to make real sure I do not crack the block or something. And keeping the oil flowing at any temp won't hurt either, since it tends to thin out at higher temps.

 

What makes you think that?

The bearings couldn't care less what was in the crankcase, only what is in the crankcase. The only reason to gradually switch over to synthetic from petroleum is to clean out whatever deposits the petroleum (or off-the-shelf additives) may have left in the crankcase.

Any "real" synthetic of the proper viscosity would be better than any petroleum-based oil for what you seem to be trying to "fix". Any viscosity-enhancing additive added to either a synthetic or petroleum-based oil would result in a brew that would be worse than a proper API/SAE petroleum-based oil for the conditions you seem to be trying to "fix".

 

Yeah. What he said...

As for the lower air deflector. the most significant pieces are the two baffles alongside the radiator support, and the lower air deflector (the one that hangs down about two inches below the radiator support). The other two baffles help, but aren't as critical as those three. They certainly shouldn't push the temperature over the edge from the heat produced by a 171" V-6.

 

So, after the tuneup is complete, I should start to rephase-in the synthetic oil? What weight should I use?
Oh, and as for the first quote of mine that was in the posts two above this one, what makes me think the engine isn't lubed as well now is the fact that all of a sudden, out of nowhere, I got a really bad valvetrain rapping I have yet to fix.

 

there is no phase in or out.


you could pour in 2.5 quarts of walmart special and and 2.5 quarts of the best synthetic oil out there for all the engine cares...


but i would just pour in the same oil.... for most of my motors i run havoline 10W-30 or 15w-40.... because its cheap, i buy it by the case, and as far as a regular oil goes, its not that bad.

i run the 10w in most SBCs, the fiero, and my dads truck.. the 15-30 goes in the extremly high miliage, knocking toyota that wont die, and my L03..... because the L03 has a slight knock up front that annoys me... and before anyone says anything about it... i dont care. if it blows a rod out the side, it doesnt matter anymore.... but the things had this knock for 5k now, and it just wont die. still making great power for a L03 too lmao. can you tell these arnt highly stressed motors? hehe



anyhoo the solution to your car is to run something thru to clean it out, put some regular oil in, and im betting that tapping is your roller liffter being gummed up from your thick sludge brew....

clean it out with some ATF or mystery oil and it should quiet down some.... if not, then fix it. *shrug* same with the airdam... the one below the radiator is the most important piece IMO..


edit: on second thought, since i just recalled you have a V6....... i donno if its a roller lifter... but as long as the valves are adjusted properly, id clean it out and wait and see before i tore apart the engine to replace the lifters.... *shrug*

my old auto shop teacher in highschool was a idiot.. he always ran straight thick oil in his motors and made us put that in other peoples cars...... welll.. one day, his vortec truck started running like ****..... i changed it to the proper oil, put some marval mystery in it, and whala... after about 10mins of idling, it started to behave....
he learned HIS lesson...... dont run thick sludge in a modern car.... you'll notice most new cars even ask for 5w or even 0w oil.... when they design the motor they even have that in mind.... so dont go pouring straigth 30w in there....

 

Where do I get that Marvel Mystery stuff?

 

Marvel Mystery Oil. I've gotten it at K-MArt, for about $2.99 a quart, or something like that. I think I saw it at Walmart too. Works well for getting rid of lifter tick.

 

(slaps self on head) Now they tell me....

 

Oh great! Now it's not Mystery oil anymore!