My '92 F150 (302 V8 5.0) has oil and a whole lot of moisture constantly in it's air box. It's gotten so bad that it's running down the driver side fender well. I don't have any major loss of oil but I've been noticing a slight loss of coolant- approx a half pint every month or so. Unfortunately, most of my driving is very short which does contribute to the moisture but having to add coolant somewhat regularly ain't good. I've read some of the other posts about the PCV valve so I will try that first. BTW, I only have 63,000 miles on this truck which is going to get me upset if it's the head gasket. Furthermore, I have no coolant on my garage floor and I don't see any around the motor either. Anybody have any suggestions? Thanks in advance.

 

danjo,

If you pull the oil plug SLOWLY (unscrew and just open up a crack) do you find coolant at the bottom of the pan? Make sure your truck has sat overnight so any coolant has a chance to separate from the oil. If there is coolant in the pan it will be the first thing out when you pull the plug. Does your oil look milky? Yeah, oil/moisture in the airbox is a sign of either a PCV valve sticking or excess oil/water vapor being produced that is in high enough volumes that it over-runs the PCV's system ability to evacuate it so it simply backs up into the airbox. Generally, with a head gasket leaking you might see bubbling in the radiator. I suppose as the engine sits idle and pressure is off the cylinders then coolant could seep into the pan and then when you run it vaporizes and overloads the PCV. You should see coolant at the bottom of the pan tho if this is the case.

Randy

 

Randy, Thanks for suggesting the oil plug test. I will try that soon. As for the oil itself, it doesn't look milky on the dipstick at all. I'm gonna put a new pcv valve in tomorrow but something's telling me I have bigger problems than that.

 

danjo,

A little bit of clear water coming out of the drain could be expected on an engine run for short distances at a time. Don't be concerned with this as this is just condensation that hasn't had a chance to vaporize with engine operation. What your looking for is fluid that is obviously anti-freeze. Anti-freeze in the oil pan is not normal under any circumtances and would point torwards head gasket, cracked head, cracked block etc. Let us know how you turn out. The guys on here have seen/heard everything so somebody should be able to help you narrow your problem down.

Randy

 

to checkfor a blown head gasket, take off the radiator cap when the engine is cold. start the truck and let it warm up until the thermostat opens. if the head gasket is blown, it should pressurize the coolant system, and either make lots of bubbles or throw cooland out of the rad, depending on how bad it is.
this isnt a foolproof test, just a verry good indicator.
eden

 

 

Thanks to all! It's looking like my head gasket is okay. I climbed underneath and it appears the bottom of my radiator has a real slow leak. That's the reason for the small amounts of coolant I've been losing. As for the moisture problem in the air box- I guess I'll just have to tolerate it for now. I have a new pcv valve in and the oil looks okay also. Because of all the short drives I take with this truck, I'm thinking about doing some different things- 1. start using synthetic oil 2. adding some type of oil treatment (like dura lube). 3. changing my oil more often. I've also noticed some engine sludge that concerns me. Thanks once again.

 

My 302 efi on my 1990 E150 van was dripping oil something fierce from what seemed like the front of the engine. It was dripping off the fan shroud, but also the vehicle has been oil sprayed since new for rust protection so there is alot of oil all around.

Had many oil change shops and mechanics look at it. Finally about 4 or 5 months after it had started a tranny place suggested looking at the airbox and pcv valve. Sure enough the air filter and breather element were soaked. Once I changed the pcv valve (I went with a factory one not an aftermarket one) replaced the air filter and breather and completely cleaned up the airbox it hasn't happened since. Try to clean out as much os the gunk as you can from the hose that leads from the pcv valve to the airbox too, I checked the pcv valve about a year after replacing it and it rattled the same as a new one so I left it alone. It's in a lousy place to get at in a van too, you need to remove the engine cover (doghouse) which on mine is a pain. Check your exhaust manifolds when you are replacing the pcv because on vans, at least, they are prone to cracking.