My best friend has a 1997 4Runner V6, 3.4L. (I know this forum is for first and second gen, but this is where I post and I am looking for advice on dealing with oil sludge in general.) He brought it to my place today to do a timing belt, general tune up, and to change out the valve cover gaskets, as they were leaking....

Pictures below:





Some of that stuff is 3/4" thick!! The pictures do not really do it justice, amazing amount of sludge on top of the heads.

He is the second owner, has had the rig 2 years. The previous owner had receipts for maintenance and for a timing belt change. Looked like a good thing. My buddy has been running Mobil 1 synthetic in it since he bought it, about 5 oil changes in 2 years.

Any thoughts on how to address this? The motor runs fine, has good power, does not make any noises, etc. We are going to do a compression check after we get it back together.

 

that'll normally bake on like that by A) using cheap oil, B) running the same oil for a LOT of miles and never changing it, and C) overheating

how do things look in the oil pan and pickup tube?

 

If it ain't broke don't fix it?

 

put the engine together and then fill the engine to proper level using a mixture of half fresh oil and mineral spirits. Then start engine run for a bit to flush it around then drain. And do this until clean. YOU CAN RUN STRAIGHT MINERAL SPIRITS THO HOWEVER MOST PEOPLE SAY AGAINST THIS.

 

We have not dropped the pan, I'm not sure you can on a '97 without pulling a bunch of the suspension out of it. Not sure, not my year of rig. The dipstick tube does not look that bad, we pulled it out to look in the hole as best we could up in the oil pump.

The motor does not run hot, now. Who can say in the past?

I told my buddy that the factory put oil in it to start, this guy thought factory fill was good for the life of the motor.

I feel like it is going to ooze out of the motor and invade my house. I made sure that the deadbolt was thrown on the garage door.....

 

Have you ever done this? What about the seals?

I also read some info on the web about mixing diesel fuel in with the oil and running it to dissolve the sludge away. I'm hoping to find someone with direct experience to learn from.

The ain't broke don't fix it opinion is attractive. It ran find this morning, no reason it won't run fine after we put the valve covers back on.

What about vacuuming the stuff out of there with a shopvac? Not my shopvac of course, I would make my buddy provide his own shopvac. Now way I want that nastiness sitting in my shopvac.

Mike

 

This forum isnt for only first and second gen...theres a sub-forum for '95.5+ vehicles ...or "General vehicle"... That engine looks...fun.....

 

i personally have used the straight mineral spirits and the mix of mineral and diesel and while both produced similar results within a few flushes i would have to say i felt better withdiesel mix because of the added lubricity and it conditions the seals

 

Is there any fire or explosive hazard with the mineral spirits? I am also worried about busting too much of the stuff loose at once and clogging the oil pickup screen or some other oil passage.

This was supposed to be a Saturday job to help out a friend, now the thing is sitting in my garage and my wifes car is out in the rain. Damn, dog house for sure.

Mike

 

lol i should check out my heads soon and see if i got that stuff in my engine.

 

All we could do was laugh, crying was not much of an option.

How to get rid of it? The motor runs fine, but with this stuff in there it is a heartbeat away from a blocked passage. The thing has cardiovascular disease.

 

honestly bro thats the worst ive seen.... do you know if the bottom end is just as bad? not that it matters but id say clean as much out by hand with rags and mineral spirits then flush the rest by running it. but you have to do something if you leave the sludge it will come back to haunt you.

-chris

 

with my ram i used to put the cheapest crap oil that i could buy into it. i wonder how much sludge is in the engine

 

lol wtf theres 2 threads. ill post in this one. i just freaked when i saw this thread thinking i might have this sludge but then i remembered when i take off my cap the head looks clean, just a bit yellow. im going to stick my finger in and see if there is stuff in places where i cant see.

 

I put an identical thread in the third gen sub-forum. Is that a forum social error? I can delete the other one. I'm trying to scare up info quickly, as we have to do something about this tomorrow.

Mike

 

i dont think that is a problem i was too lazy to repost in the other one

 

If it was mine I'd flush the engine with some Mistery oil. When I've used it before just do an oil change with cheap oil and new filter subsitute one qt oil with the mistery oil. Run it at idle for 15-20min and drain. But as bad as that sludge I'd buy an extra filter a swap it out 1/2 through. Have used ATF as well.

But be aware that its been reported to me and makes sence that if you get all that sludge out then you might start have heavy oil burn. Because the sludge acts as a seal. Never happened to me.

How many miles? and mobile 1 hmm.

 

155k miles on the rig. He started using Mobil 1 after he bought the Runner, when it had 135k miles on it. He changes the oil every 5k miles, even with Mobil 1 in it.

Thanks for the pointer on the heavy oil burn.

Mike

 

At the very least I think you could put some nitrile gloves on and just scoop some of that crap out.

I've never heard of the mineral spirits thing.

 

I don't see a problem there.



Wonder if the PO ever changed the oil