This photo is from around when I first bought my truck. It had 165k miles on it at the time. Here's what it looked like under the valve cover:

https://i.imgur.com/27qgb.jpg

How bad does it look to you? What caused this? Infrequent oil changes? Overheating?

The engine seems to run okay. I had to retard the timing a little and run 89 or it pings a bit on the highway. It burns a little oil too, but not terrible.

Is it a problem? It is going to clear up if I properly maintain the engine in the future?

 

165k ? looks like mine looked at 296k!

 

maybe somebody skipped a few oil changes?
maybe run some ATF through the oil for a few hundred miles before you change?
or do the seafoam?

 

That doesn`t look good, but i`ve seen worse. As said above, try running some sea foam or ATF through the engine for a few hundred miles, that should help clean things up.

 

I'm thinking I'll Auto-Rx it.

 

Why?
ATF and Seafoam are the best treatments, especially since everybody on here even suggests using the two.
I ran ATF through my engine for about 500 miles, and noticed a much cleaner running engine, and my oil is definitely cleaner, too.

 

My best friend bought a used '96 4Runner with the 3.4 a few years back. We did the timing belt and decided to do the valve cover gaskets while we were working on it. The motor was sludged, totally clogged with gelled oil, not the residue that you see in yours. We ended up washing it out with diesel with the pan off and scrubbing the stuff out with nylon brushes. Then, ran two cycles of idling with BG Quick Clean. It is an engine cleaner that you don't drive around in, only at idle for 15 minutes or so.

We then ran the full Auto RX sludge cycle through it. The motor is still going strong a year later.

Thread, if you are interested:

https://www.yotatech.com/forums/f2/o...ttacks-167704/

 

That doesn't look great, but it's not horrible either. My money is on the PO stretching drain intervals way too far. The type of driving also has a bearing on how long the oil lasts. Lots of highway miles are easier on everything than lots of city miles.

 

If he were to run diesel or some other type of cleaner through the engine is there anything else to clean out and clean from all the loose sludge like an oil pan screen or anything or will the regular oil filter catch it all and then just change it soon?

 

I have often heard about using ATF to clean an engine, but have never gotten good clarification as to how to use it. How much do you use? (ie. do you substitute 1 quart with an oil change and drive normally for 3,000 miles, or do you run 5 quarts ATF at idle only then drain?) Also, do you use Dextron/Mercron, Type F or what?

Thanks.

 

Dude, LOVE the avatar!!!

That right there is a damn good question! I used to run ATF down the throat of my carbed rigs (not Toyota) years ago to clean out the cylinders.

Anyone have info on this or is it just like running Seafoam? Some in the tank, some in the crank case and the rest through a vacuum hose?

 

I just poured a "bunch" of ATF into my valve cover about 500 miles ago.
I wonder if the ATF down the throat would work..
Did you just drip it in while it was running or what?

 

When I throated mine it was on carbed IH Scouts. I just poured it into the carb while I kept the idle high enough not to die (around 2500rpm). It makes smoke like a fiend. This also might work with an EFI engine if you run it through a vacuum line like you do Seafoam.....

 

While researching how to clean my buddy's sludged 3.4, I did a bunch of reading using ATF to scrub the motor out. Bobistheoilguy.com has a lot of good info on this. From what I read, that whole theory applied back in the 60's and 70's, when motor oil had little to no detergents in it. Modern oil has the same, if not more detergents than ATF. The opinions on that site ran towards ATF not being much different from modern good quality motor oil.

Not sure what to believe with ATF, have no personal experience with it.

 

A couple ounces of Seafoam, quart of ATF, and some cheap motor oil will do the trick. Dont put too much Seafoam into the oil or it will thin it out too much.
On my Civic that I put 600 miles a week on, mostly highway, I run the cheapest oil and never let the oil get older than 2400 miles. 190K miles and the valvetrain is still a beautiful silver/yellow.
Running cheap oil (assuming you arent racing or in extreme conditions) and changing it out often is better than running high dollar oil and extending intervals.

 

I'd ignore all that.

From experience, leave it be. Believe it or not, I'd be willing to bet money that there's gooey stuff on your seals that are actually sealing the engine better because the seals themselves are old, dried, and don't seal anymore. IF you run stuff through your engine to clean all that crap out (which the seafoam or ATF absolutely will do a very good job) you're also going to clean out all that gunk that's sealing your engine from leaks.

IF you run stuff through there, just be prepared to start replacing crank seal, rear main seal, valve cover gasket, etc. Hopefully your rings and valve seals are in good enough shape that you don't start burnnign oil worse.

I'd just leave it be, and keep on top of your oil changes. If it gets to the point that it's burning way too much or you're losing oil pressure because it starts to sludge up, then it's time to start looking in to either a cleaning/rebuild, or replacing the engine. Until then I'd just run with it, or you're just opening yourself up to problems.

 

I would tend to agree with pb4ugotobed if it's not broke don't fix it. Although not good the valve train doesn't look as bad as i've seen in the past. He's right when it comes to seals working better with the gummy stuff holding them together, When you're ready to rebuild or replace the head or timing assembly then and only then would i try and clean every thing out to get a freah start. But be warned when you clean it out be prepared to open a new can of worms when it comes to rebuilding. Then again it could all be in our heads and if or when you clean it out it could be fine with a clean top end. good luck keep us posted.