fj4o motor oil turning black too fast?

[Gijs]

Hello,

I just changed oil and filter a few days ago and took my FJ40 cruiser for a drive into the mountains this weekend. When I checked the oil today the color was quite black, after only like 300 miles of driving. I did ask a lot of my engine (2F) while driving in the mountains but is this normal?
Also the outlet shows a little bit of black smoke while driving.

Maybe the carburetter has be fine tuned?

The engine is not burning any oil, the oil level is fine.

Also gas mileage is pretty bad, around 7 mpg.

Thanks in advance for the replies, greetings from Bolivia,

Gijs

 

[FJforty]

Check the PCV valve. Carb problems sound right. Check your plugs. They should be cream colored if fuel/air mixture is right.

 

[Gijs]

Thanks! Plugs seem alright. Will have the car checked by a mechanic tomorrow. What is a PCV valve?

 

[TLCHopII]

PCV = positive crankcase ventilation
It is a small valve between the valve cover (top of engine) and the air cleaner housing. Look at SOR's website engine/air cleaner assembly break down drawing for your yr & model. The pcv valve is a check valve: a one way valve that allows pressure inisde the engine block to be relieved into the air cleaner housing.

Cheap part. IMO just locate it and change it out. If you see a marked improvement then cool if not your down a couple bucks.
I typically change the pcv vavle out during routine maintenance (spark plug, points etc.)

 

[Gumby]

It sounds like you are running way too rich if you have black smoke at the exhaust. That will certainly cause the oil to get black quick. Easy checks are seeing if the choke is partially on or if fuel is dripping from the venturis.

You might also be running rich because you are running at a higher altitude than the truck is set up for. A Bolivian mechanic should know how to re-jet for altitude. Less oxygen means the truck should be trying to mix less fuel.

 

[Living in the Past]

The PCV is not the hose on the valve cover. That is just filtered makeup air to what is being pulled out by the PCV. The hose at the base of the carb is one end. the valve should be at the other. On the F135 and F145 it is on the oil fill tube. On the F155 ahd 2F it's on the side of the engine. Should be a connection on the cover plate for the lifters. That is if the South American cruisers got them. I don't see why they wouldn't have but you never know.

 

[Gijs]

Yes it seems I am using too much gasoline. I guess to correct that problem it is a matter of fine tuning the carburetter. I had a mechanice working on the carburetter a week ago because imo my cruiser didn't have enough speed/power. Before that the oil didnt't get black so fast, nor was the exhaust giving black smoke. The mechanic here said the black smoke from the exchaust would disappear with time, well it didn't. The car does seem to have more power and speed now.

The altitude wasn't a problem I think, only like 3000-4000 feet.

 

[TLCHopII]

The PCV is not the hose on the valve cover. That is just filtered makeup air to what is being pulled out by the PCV. The hose at the base of the carb is one end. the valve should be at the other. On the F135 and F145 it is on the oil fill tube. On the F155 ahd 2F it's on the side of the engine. Should be a connection on the cover plate for the lifters. That is if the South American cruisers got them. I don't see why they wouldn't have but you never know.

thanks for the correction. It's been awhile since I owned an F engined cruiser.