Snot in the valve covers - not in the oil, losing coolant internally.

[strangewayes]

I just purchased a 1988 Ranger STX to fix up. It has a check engine light but the obd1 port doesn't work, so I'm flying blind as to what it's saying.

When I pulled the PCV valve, it was coated in yellowish goo, along with some inside the valve cover and along the edge of the oil fill cap. Rather thick and snot-like. There does not appear to be anything in the oil when I pull the dipstick. It is honey-colored like it should be. The oil level is not rising.

The radiator lost about 1/3 of a bottle of antifreeze after being driven for 30 miles. No visible leaking anywhere, so its internal.

The engine has a slight miss, but runs well. It smokes a tiny amount on startup but goes away completely after warming up. On the highway after about 15 minutes of driving, it'll start to hesitate if you accelerate at highways speeds.

Do you guys think its a bad intake manifold gasket, or am I going to need to replace head gaskets?

Thanks!

 

[RonD]

Welcome to TRS

The "snot" in the valve covers is condensation mixed with oil vapor, replace PCV Valve, clean PCV valve hose and Vent hose(in opposite valve cover from PCV).

You know how you get "fog" on the inside of the windows in the cab when air outside is cold.
Or the outside of a COLD glass of beer on a warm day collects water.

Same thing happens inside the valve covers when you shut off the engine.
Any moisture inside the engine collects on the cooler parts, which will be the valve covers, oil cap, and PCV valve as they cool off faster than other parts

Usually if engine is started and run for 15-20minutes all the moisture inside the engine will be "burned off", evaporated.
So when it is shut off there is very little moisture left in the valve covers, and the PCV Valve also circulates the air.

If engine is started cold and only driven for 10min or less, moisture is still inside, repeat this for a few days every week and you get that "snot".
So short drive to work is great for gasoline, and miles on odometer, but NOT GREAT for the moisture level in engine.


Blown head gasket/cracked head test, Glove test
Cold engine
Get a Latex glove and rubber band, or a balloon, or a Condom
Remove rad cap
Remove overflow hose from rad, and block that port, i.e. gum, vacuum cap, tape, ect.........

Put glove sealed with rubber band, or balloon or condom over rad cap opening

Pull off the coil wire on distributor, you want a No Start

Crank the engine and watch the Glove
If it bounces up and down then you have a cylinder leak, i.e blown head gasket or cracked head

If it just lays there then all is well

If it does bounce, then remove 1 spark plug at a time and crank engine
When glove stops bouncing last spark plug removed was from leaking cylinder, put spark plug back in to confim

Each cylinder will have 150psi on it's compression stroke, thats what causes the glove to bounce if there is a leak from cylinder to cooling system, which is a blown head gasket or cracked head

Hot coolant can evaporate pretty fast if leak is running down any warmed up engine parts.
Cooling system only has pressure once coolant warms up, so a smaller leak won't leak much until engine warms up.
Check over flow tank, if it is getting overfilled then you have a head gasket issue


1988 Ranger 2.9l will use a TFI spark module, as they get older they are known to cause problems when they warm up
Good read here on those: http://www.therangerstation.com/tech_library/TFI_Diagnostic.shtml

BUT(big but), there are several things that can cause acceleration issues, especially after warm up

 

[strangewayes]

Wow, Thank you Ron. I've got homework to do now, thanks to you! I'm excited to find there's a chance I might not be tearing the engine apart.

 

[wildbill23c]

My 84 Bronco 2 had this problem as for a while it only got driven for short distances. Same issue with my 88 Bronco 2 for a couple months while I was trying to get money to rebuild the transmission. Now that I drive it daily and further distances I have not had any of the condensation issues.

 

[adsm08]

Check your freeze plugs for leaks. I have a 4.0 that had a lot of mystery loss, thing goes like 16 miles a week and would loose almost a gallon a week. It was the driver's side freeze plugs, two had pin hole leaks that would spray a fine mist that never settled anywhere.