Best and safest engine flush

What is your idle rpm? It should be 750 in park or neutral and if you have the automatic 600 in gear.


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Is Marvel Mystery Oil only for the long term OR does it begin to clean engine , especially the screen on the oil pick-up tube, quickly.

2nd question: Since I am getting the oil light only at IDLE, but not at 800 RPMS and up, would driving the T4R do damage to engine ?

Do not leave MMO in the oil for too long. Pennzoil Platinum has some pretty mean detergents as-is. Your idle does sound very low. 750-800rpm is normal idle. Can you see sludge on your dipstick?
 
You said in one post that this thing is a v6 2wd, so why not just drop the oil pan and see if the pickup tube is clogged up and if the pan is full of crap? Cant be that hard to do. Not like the front diff is in the way
 
Do not leave MMO in the oil for too long. Pennzoil Platinum has some pretty mean detergents as-is. Your idle does sound very low. 750-800rpm is normal idle. Can you see sludge on your dipstick?

No, I can not see sludge on my dip stick. But, I drained a bit of oil and it is one heck of a lot blacker than I think it should be, considering that I had driven it only 20 mile since the oil change. I had just changed the oil an hour before the problem started. Because I had read that using 10W-40 (Valvoline) would help me pass the California smog test, that is what I put in.

Since I just bought the vehicle I have no history on it.

Seems extremely suspicious that the problem started only an hour after the oil change.

A trusted friend, who is a professional mechanic on small engines, has urged me to flush with 1 gallon of diesel fuel and 1 quart of motor oil, leave it in overnight, then run the truck for 5 minutes and then immediately drain it. I have not yet done it, but he makes a strong case.
 
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You said in one post that this thing is a v6 2wd, so why not just drop the oil pan and see if the pickup tube is clogged up and if the pan is full of crap? Cant be that hard to do. Not like the front diff is in the way

If a flush does not solve the problem, and a new oil pressure sending unit, I may be forced to drop the oil pan. But, not as easy as it seems. You must remove one hell of a lot of parts to drop the oil pan.
 
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If you have the oil light coming on, before flushing anything, get a oil pressure tester and see what the pressure is at idle when hot. A flush can’t hurt. MMO takes time to flush away all the sludge. I never have gone past two weeks with it in any crankcase but have known others to use it every time they do an oil change without any problems so YMMV.
 
If you have the oil light coming on, before flushing anything, get a oil pressure tester and see what the pressure is at idle when hot. A flush can’t hurt. MMO takes time to flush away all the sludge. I never have gone past two weeks with it in any crankcase but have known others to use it every time they do an oil change without any problems so YMMV.


Yes, I will be doing an oil pressure test but I have to wait for Amazon to deliver the test gauge and the new oil pressure sensor. In the meantime I'll do the flush and see what happens.

But, even before that, I must wait for my new alternator to be delivered.
PS; What is YMMV ?
 
Yes, I will be doing an oil pressure test but I have to wait for Amazon to deliver the test gauge and the new oil pressure sensor. In the meantime I'll do the flush and see what happens.

But, even before that, I must wait for my new alternator to be delivered.
PS; What is YMMV ?


ymmv= your motor might vomit
to much of the wrong oil the motor will take a puke

kidding... it used to mean.. your mileage may vary... such as how often you use it etc
 
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Yes, I will be doing an oil pressure test but I have to wait for Amazon to deliver the test gauge and the new oil pressure sensor. In the meantime I'll do the flush and see what happens.

But, even before that, I must wait for my new alternator to be delivered.
PS; What is YMMV ?

If you see anything below 4.5 psi at idle (oil all warmed up), then I would try the flush but I would think that pulling the pan would get you further ahead to discovering whether a good initial cleaning would be the best course of action.

Any lower motor noise by the way?:hiding:
 
These flushes are all fairly aggressive and last resort-ish. No way I’d be doing one before checking my oil pressure with a gauge. Do your proper diagnosis first, the flush may not be needed and may cause harm.

Think of putting on a cast before the x-ray, backwards logic.

You mentioned that the oil pressure light came on AFTER you did an oil change. Cause and effect, I’d be thinking about that. Might be coincidence, might not be.
 
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2 symptoms.
Oil light at idle and oil dark after 20 miles.

Filter is downstream of the sensor, so not likely the issue.
Thinner oil should make for less pressure than thicker oil, so 10w40 isn’t likely the cause.

I’d run cheap filters till your done flushing at least.

You can look in the oil fill cap for sludge. Generally you’d do that before purchase, not after.

I run Marvel for the last 250 - 500 miles before an oil change if I want to clean an engine.

For your case I think I’d pour in a quart of marvel and then run the engine with no load at a high enough rpm to keep the light off. Every once in a while let it idle and see if light comes on. Do this for about 10 minutes. Then let sit overnight and then repeat the run test.
Assuming light still comes on, then drain the oil and pour in 2 gallons of diesel. Let that sit overnight and then drain and replace filter and fill with cheap 10w30 or 5w30 and start it up and check light.

If no light, then dump in a half quart of marvel and run it for 500. Then do an oil change with good oil and filter.

If still a light, then get a pressure gauge, and/or get invasive with the oil pan and oil pump.
 
If you see anything below 4.5 psi at idle (oil all warmed up), then I would try the flush but I would think that pulling the pan would get you further ahead to discovering whether a good initial cleaning would be the best course of action.

Any lower motor noise by the way?:hiding:


LittleCaesar, I am deaf, or nearly so. But my friend assures me that he can't hear any unusual engine noises what-so-ever. No knocking, pinging, thumping, grinding, clicking or tapping. Just the sound of a perfectly running engine. During the trial run , prior to buying, we both were impressed with it's power and smoothness. The truck ran like a scalded cat. Oh, and no dashboard warning lights prior to the oil change.
On it's 2nd day on the road, all hell broke loose. 1st, the car died on the freeway; it was running on battery power alone. The brand new battery had worn down to the point where even the flashers would not work. Luckily for me there was an Auto Zone at the foot of the off ramp. I had Auto Zone recharge the battery and test the alternator. They said, "positively the alternator was bad". During that alternator test was when I first noticed the oil light come on at idle, but NOT when I increased the RPM's. Yes, the oil level was right where it should be.

I can't imagine that the two things are in any way connected. But, I suppose anything is possible.
 
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If you see anything below 4.5 psi at idle (oil all warmed up), then I would try the flush but I would think that pulling the pan would get you further ahead to discovering whether a good initial cleaning would be the best course of action.

Any lower motor noise by the way?:hiding:


I'm sure you are correct. However, I am no ones idea of a mechanic and according to Haynes Repair Manual, the following is necessary before removing the oil pan: remove front stabilizer bar, remove exhaust assembly, remove front crossmember, remove the A/C compressor, remove alternator, remove the crankshaft position sensor from the timing cover, remove the left and right stiffener plates, remove the transmission brace. Only then can the pan be dropped for cleaning the pan and oil pick-up tube.
I appreciate your advise, but doing all of that is WAY over my head. :eek: :noidea:
 
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When I replace the alternator, I will double check the RPM's in gear and at idle. The old alternator was not charging the battery.


Your low rpm at idle could be your low oil pressure. My rebuilt engine on a hot 95 degree day after driving 22 city miles home from work had about 8-9psi at idle in park at 750rpm with 5w30.


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Your low rpm at idle could be your low oil pressure. My rebuilt engine on a hot 95 degree day after driving 22 city miles home from work had about 8-9psi at idle in park at 750rpm with 5w30.

Hmm. Darn good point. I had not thought of that. As soon as I get the new alternator in, that will be the 1st thing I check. Thinking along those lines, I seem to recall that when I cleaned the MAF with CRC MAF cleaner, the idle speed did indeed drop a tad. Thank you very much. :thumb3:
 
No unusual sounds is good news. In the best situation here, it may just be that the sensor went bad.

I remember on the other board Yotatech a guy had a 99 that had close to zero pressure at hot idle. He pulled the oil pan, found that the pick up screen was clogged, unclogged it, did two flushes, and drove it for a number of year there afterwards.
 
BG 109

I use it regularly on my S Series Saturn to keep the oil rings unstuck.

In fact all BG products are awesome.


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I'm fascinated by this stuff, I've heard whispers about it before but never knew what it was. I'm also fascinated by the $40 a quart price on Amazon. What's this stuff made of, and how does it work?
 
Hmm. Darn good point. I had not thought of that. As soon as I get the new alternator in, that will be the 1st thing I check. Thinking along those lines, I seem to recall that when I cleaned the MAF with CRC MAF cleaner, the idle speed did indeed drop a tad. Thank you very much. :thumb3:


The IAC is known for getting crap in it and sticking.


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