Carbon deposits inside valve cover

[yellowhouse]

Hi guys.

I'm in the process of baselining my 92 3FE today I started the valve adjustment process. (That flywheel window process was a real chore...) When I got the valve cover off I found a massive amount of carbon deposits, and not just on a few spots--this stuff was everywhere.

A little background: 206k miles. I've only owned the Cruiser for a short period of time. Looks like there was a massive oil leak of some sort as the engine bay is caked in oil and dirt, but since owning it I haven't noticed any leaks at all.

What could be the reason for the carbon deposits? How should I go about cleaning up this gunk?

Also, I obviously didn't finish the valve adjustment. I know the FSM recommends adjusting while the engine is hot but I've read some threads where users found negligible variance when adjusting cold. Anyone care to offer their two cents? Thanks!

 

[cybrstar]

Time for a V8 or diesel.

 

[Tools R Us]

Meh, kinda normal for a F motor, they don't circulate much oil in the valve cover.

 

[yellowhouse]

I'm no mechanic, but for reference this is what I was expecting things to look like when I opened up the valve cover.

 

[goranvolvo]

usually you get that when you go to fast oil change places their oil is poor quality most oil is recycled ,cleaned and added additives that oil can't handle the heat and breaks down ...

 

[Seth_O]

I'm certainly not an expert, but looks like maybe a valve is leaking exhaust into the valve cover?

 

[Rifleman]

In my experience, sludge and carbon buildup like that are all tell tail signs of a previous owner who skipped doing oil changes as often as he should have. This is one of the reason why you want to follow a recommended maintenance schedule for oil and filter changes, so problems like this don't happen.

 

[BILT4ME]

Yep! This is a PO that never changed the oil often enough.

Good chance of piston rings that are caked, oil galleys, all that.

Some will recommend Seafoam (DON'T DO IT!). Depending on how far you're planning on going here will define what you do.

You can put it back together and run high quality or diesel oil in it and change it frequently as long as you are driving it regularly. This will clean it up some over time.

You can also pull the pan and wash everything down from the top with parts washer fluid and such to rinse out all the crud and let it all fall out the bottom but that means you are disturbing it and making it come loose so it COULD get where you don't want it.

Otherwise, pull it rebuild it, and run it. Kind of extreme, but it looks like it was pretty seriously neglected.

 

[scottryana]

Is it your daily? Is it a weekend toy? Just used on the farm? Going to be used for a 2000 mile adventure?

The answer to those questions would determine what I was going to do.

If it is just used occasionally and a toy, I would throw it back together get an oil with higher detergent content like a good diesel oil. And run it changing frequently and pull the valve cover in another year.

If the truck is your only transportation or going to be used for a long remote trip, I would pull the engine and rebuild/replace.

 

[Tools R Us]

Yep! This is a PO that never changed the oil often enough.

Good chance of piston rings that are caked, oil galleys, all that.

Some will recommend Seafoam (DON'T DO IT!). Depending on how far you're planning on going here will define what you do.

You can put it back together and run high quality or diesel oil in it and change it frequently as long as you are driving it regularly. This will clean it up some over time.

You can also pull the pan and wash everything down from the top with parts washer fluid and such to rinse out all the crud and let it all fall out the bottom but that means you are disturbing it and making it come loose so it COULD get where you don't want it.

Otherwise, pull it rebuild it, and run it. Kind of extreme, but it looks like it was pretty seriously neglected.

Most often this is caused by excessive cold running, short trips, where the motor isn't allowed to fully warm. One fix is longer drives, but for the earlier motors is mostly normal. If it runs well, wouldn't worry about it

 

[BILT4ME]

Most often this is caused by excessive cold running, short trips, where the motor isn't allowed to fully warm. One fix is longer drives, but for the earlier motors is mostly normal. If it runs well, wouldn't worry about it

This is absolutely correct! I thought about it later after I made my other post!

Is it your daily? Is it a weekend toy? Just used on the farm? Going to be used for a 2000 mile adventure?

The answer to those questions would determine what I was going to do.

If it is just used occasionally and a toy, I would throw it back together get an oil with higher detergent content like a good diesel oil. And run it changing frequently and pull the valve cover in another year.

If the truck is your only transportation or going to be used for a long remote trip, I would pull the engine and rebuild/replace.

@scottryana is so right here! Depending on what you're going to with it makes the path forward go different directions.

 

[woodsman 44]

This is from lack of oil change...lots of old oil sludge build up, seen this before...

 

[yellowhouse]

Is it your daily? Is it a weekend toy? Just used on the farm? Going to be used for a 2000 mile adventure?

We plan to mostly use it for touring/camping. I am trying to convince my wife that Lando will be reliable enough to make the 600 mile trek up to Banff National Park once the engine is tidied up... As for daily use you could hit a golf ball from my house to work so I try to walk instead of drive--especially now considering the comments about short trips. (I've only done this a handful of times so don't blame me!)

I think I'll do my best to remove the big chunks of carbon and totally clean the inside of the valve cover, as that seems like something I can safely do. Then I'll take scottryana's advice and change the oil/filter with a good diesel oil. Anyone have any recommendations on which brand or type? And how many miles should I cycle it through before giving it another go? How do we feel about Marvel Mystery Oil?

Thanks for your help, guys.

 

[scottryana]

I would go with a Mobil 1 Diesel engine oil, or if you want to save a little money Mobil Delvac or Shell Delo 400.

I would try and get at least one good long drive in a week, get everything nice and hot. Since you aren't going to be doing a lot of miles I would change it based on time. 3 months/2500 miles.

 

[BILT4ME]

Each drive should be a MINIMUM of 30 minutes with a mix on highway and slow road stuff. Something to make sure it gets well heat-soaked to loosen up this stuff.

I would do them on shorter intervals first (1000 miles) to see how cruddy the oil change is. A lot of others here also use Rotella T diesel oil, but I like the Mobil and Shell listed.

 

[cruiserhound]

'91 3FE 245k. Par for the course! Put the cover back on and drive her.