How do I clean this?

I just removed my valve cover on my 1996 Tacoma 4x4 and found this gunky mess. How should I go about cleaning this up and what do you think may have caused it? I'm guessing 355,000 miles has to have played a role.
see attached photo
I'm new to this forum so thank you for any ideas and suggestions. My son and I are trying to get this old friend back in shape.

 

I would strongly consider cleaning off anything loose, ensuring oil passages are clear, and leaving the rest. If you get too gung go, there’s a decent chance of getting cleaning agents where they shouldn’t be, or getting debris into the engine where it would be far more likely to be problematic.

 

Agreed, I'd probably try and shop vac anything that's loose but not mess with it further.

 

I believe extended oil change intervals and/or lower quality oil would be your culprit there. I've seen inside several 5vz's with ~300k miles and they were nearly spotless with just a tad bit of staining to the cam assemblies (and they'd had regular oil change intervals).

FWIW, some recommend frequent oil changes with oils that have a lot of detergents in them, as a method of cleaning something like that up over time.

 

Somebody must have babied it it's whole life if oil never got up there to clean off dirt lol
x3 for just some mild cleaning. The cam lobes look great, no scoring or burning. I'd just get off whatever half a roll of shop towels gets off

 

clean what you can with vac, change oil and add seafoam to crankcase and change every 400-500 miles

 

To add to my post above, you could do some shorter oil change intervals with a high detergent oil to break it free in a gentle way. I run SuperTech in most of my high mileage vehicles. I'd advise against adding SeaFoam, ATF, or any other fluid to the oil with the intention of cleaning up deposits. It does work but it can free up enough of it at once to clog oil galleys or the pick up in the pan and create new lubrication issues... I did just that once and grenaded a previously running engine

 

It made it to 355k miles, why poke the bear?.
Replace the valve cover gasket & move on.
Unless your willing to pull the motor to flip it upside down to clean the top end & drop the oil pan to clean the oil pump screen, I'd leave it alone.

 

I've seen worse. A few short interval changes will clean that up. Use a good filter. All modern oils have enough detergents to do the job.

I'd do a 500, 1000, 2000 change then go to 5000.

I'd bet money that one has seen longer intervals, lots of *cold* running (short trips) and possibly a oil with a bit heavy viscosity.

But as someone else mentioned, I'd not fret over it too much.

Tip. If the underside of the valve cover is caked you can absolutely clean that up nice and shiny in a parts washer. Dry the solvent out well before reinstalling, then your oil changes won't be working on cleaning up that mess.

 

This.

 

Thanks to everyone. Your suggestions mirrored my thoughts. I suctioned all the loose crud and wiped everything down I could safely reach. I'll be doing multiple oil changes next and I think this beast of a truck will be just fine. Again, thanks for the suggestions.

 

Liquimoly makes some excellant produtcs.

 

I would go buy the walmart $17 oil and change every 500 for 3 or 4 cycles...
mid level Fram...

and then keep doing em at 4K mark with some premium antiwear oil...

I would not use a flush....your way past that.....


that main seal could start leaking ....old oil, old power steering fluid turns into pre-grited cutting fluid...

May have to add some of that AP205 reseal from ATP...
that SuperTech high mileage oil from walmart should already have something like that in it....


Myself I just buy Napa syn blend they put on ad slick for $12.99....



Man the stories keep coming....I love you guys.....

 

If you do nothing but stop and go commuting....like me...
I would cut oil and trany changes at just above half....

I think half my engine revolutions happen in front of a red light....

And your supposed to do go blow them out on highway every so often...for a bunch of reasons....at least a half hour...

My brother followed the oil change recommendations when he got his new prius...even skipped a few....
years later.....uses a quart about every 600/700 mi.....


I would be highly suspect of all fluids on the truck.....
Now a days a differential can cost as much as a transmission on these old girls....