Hello all and thanks for the wonderful advise I have read so far in these forums the past couple of days, it has really helped my decision on purchasing this truck but now I have came back to ask a few questions of my own. Truck is a 1981 F100 Custom with a 300ci Inline 6. The first problem that I noticed was there is a white/tan colored foam on the dipstick and under the oil filler cap, from what I have read this can be caused by condensation, if it was condensation would there be a small amount floating in the oil under the filler cap? ANother concern was during the test drive I heard the hissing noise coming from the engine....Maybe the vacuum lines? Is there a diagram or picture that shoes where all the hoses/lines connect in the engine compartment? And the final issue is when you come to a stoplight the truck idles rough (up and down RPM's) Could this be caused from the vacuum lines? When it is in park it idles fine. Thanks for any advise that can be given..
Well, I guess I explained that a little wrong. It is more of a foamy substance than "water" floating in the oil. I noticed that there are a few hoses that are not connected as well. I will shot some pics tommorrow and post them. Thanks for the help. how do you post a pic?
Damn. Typed a couple hundred words and C. beat me to part of it. College internet is terrible.
Anyway, sounds like HGs. You could have a bad filter gasket, bad repairs, and an engine that sat and got moist. But, odds aren't in your favor. Google bad HG. To me looks like the bottom of a milkshake or sundae. Hoses should be easy to hook back up based on diameter and length. That will cause the bad idle.
Once it's buttoned up get a can of brake cleaner or starting fluid. Spray around gaskets and hoses. Anywhere that's leaking will cause a change in exhaust color or the idle to pick up. Change the oil stat and see if it gets that way again. What's your coolant look like? Does the expansion tank or radiator hold pressure long after you quit running it?
Ok, I went out this morning and drained the oil, and it looks as good as new. I assume that is a good sign? I was also told last night to make sure the PCV Valve and the hose running from the PCV valve were clear of any carbon buildup. That person also commented and said something about removing the PCV valve while the truck is running and you should be able to tell if it is bad from the way it would idle....I did not quite understand this procedure. I am going to try an shoot some pics today (if it clear up outside) and post them for the further more in depth questions that I have..thanks for the help so far....CTubutis...You almost bursted my excitement bubble last night!
Ok, I went out this morning and drained the oil, and it looks as good as new. I assume that is a good sign?
It could be (a good sign) but it could also be an effort by the PO at hiding a problem, just like new tires will mask a front end problem for a while.
It still concerns me, though, and I'd do a leak-down test and look for air bubbles in the radiator. Again, water will sink, oil will float.
Have you looked at your radiator fluid at all?
Originally Posted by Va_Cleaner
CTubutis...You almost bursted my excitement bubble last night!
Believe me, dude, there's not much happiness on this side... Here's a newbie who has apparently been lurking for a while and used what he learned here to go purchase something of his own (great!) but sounds like it might need some semi-major engine work (ugh).
Speaking of which, go HERE and finish filling out your profile so we can see where you're from when you post?
sounds like vacum leaks, i have this exact same engine only in a 150, when i went to replace a valve cover gasket it was coated in a penut butter colored cream, wet old oil, change the oil a few times clean as much as you can, and plug the vacum lines that are not conected, these engines are bullet proof, i dont think you have to many "major" problems, vacum leaks on these engines are the worst, especially with all the polution control stuff on our year of trucks, i pulled the egr valve off of mine and plugged i swear 100 hoses runs like a top, just get the hoses plugged and i bet it will run beter
If it is your head gasket, you may not be too bad off (yet). Has your temperature spiked at any time while driving it?
I would say, if in question, replace the head gasket. It will save you some (or a lot) of work later rather than a short amount of time and money now.
Plus you'll see a lot more about the condition of the engine. Have access to any inconveniently placed stuff, and get to check other hoses, etc. for leaks.
From what I see, it's not back on these 300's. I've done HG's that took two full days and almost 1k in parts. Everything you need should be in stock locally. Pick up a 6pack, and another in case it's bad news, and go exploring.
Wow, after a long 36 hours I have fixed the problem and she is running as smooth as a baby's a$$. To start things off, I spoke with a few people at Advance and they all recommened a bottle of Seafoam..through half that in with the oil and after running it for a while the mositure and "foam" was gone. Then my long time friend/mechanic came over and we replaced the carb (Reman OEM), Radiator & hoses, Heater core, Complete engine flush, transmission flush, replaced all fluids, plugs, wires, d.cap, oil filter, PCV valve, front tie rods and ends, and new front tires. Well needless to say she's running just like I though...excellent!! Now were having a few beers, going to sleep and going for a ride tommorrow. Heres some pics I shot a few mins ago, Thanks
What is that hose on top of your carb? The one on the side that goes straight down. My carb is capped off there. Thanks to the PO, my engine is a cluster @#&$! He hacked all the emissions and hoses and i'm trying to find a how to on hooking all those vac lines back to factory specs for dummies. Im not an engineer and don't really understand the vac diagram on the hood lol.