Hi guys,

Finally got around to some general maintenance procedures that were much needed such as cleaning the throttle body, checking the PCV valve, and replacing the crankcase breather.

The throttle body had probably never been cleaned, the PCV valve was full of deposits and oil, and the crankcase breather was full of sludge, which leads me to the topic of this post.

The crankcase breather was in need of being replaced, so I replaced it with an open air breather, however, is this recommended over the stock breather assembly that vents from the air cleaner? I'd think the difference would be minimal, but any input is appreciated.

Hopefully the attention to these items should improve the performance and fuel economy of my truck. The best MPG I've had so far was 15, the worst was 11.


Stock Crankcase Breather

Spectre Performance Crankcase Breather

Dirty Throttle Body

Clean Throttle Body

 

If there's enough blowby that it'll blow past what the PCV valve can handle, it'll blow oil out; but it's not measured or metered in any case.

(For my MAF based 1991 Cougar, It Would Be A Very Bad Idea. For a MAP/Speed density system, Eh, Who cares?)

If it does start blowing any oil out, you might be able to swap to a Fram or other aftermarket PCV valve, which will increase your oil consumption but will keep the blowby under control.

While doing this, don't ignore the O2 sensor! Also, what's your oil consumption like?

RwP

 

Thanks for the reply.

The air filter that was installed when I got the truck was contaminated with oil, the PCV valve was semi-clogged with oil and buildup, the crankcase breather was sludgy on the inside, and the throttle body showed similar oil contamination and buildup. The previous owner did a terrible job maintaining the truck, and any 'maintenance' or 'repairs' that were done were poor or incorrect.

The air filter is relatively new, I cleaned the throttle body and PCV valve yesterday (valve rattles as it should, but I'll spend the couple bucks for a new one), and replaced the crankcase breather today.

After I got the truck running, it had some drivability problems due to the installed oxygen sensor's wiring being split. The sensor has since been replaced and said problems were resolved.

With new, clean filters, a working oxygen sensor, and a working PCV valve, I'll keep an eye out for any oil originating from the PCV valve contaminating the filters.

As far as oil consumption goes, I can't say I have much of an idea. I changed the oil about 1,700 miles ago since the oil was 10+ years old. I'll have a better idea after I put some miles on the truck.

 

If you buy a new one, spend a bit more.

Get the OEM Mopar one.

Anecdotes are not data - but on my 1991 Cougar, my oil consumption dropped from about a quart every 600 miles to a quart every 1,500 miles by merely replacing the Fram PCV valve with a Motorcraft one, due to the Fram "Suck it all let the cat sort it out!" philosophy of "One size sucks".

My Dakota, before the rebuild, also improved oil consumption. Not much; it was a leaker, but it DID improve going to a Mopar PCV valve.

RwP