I just purchased a '85 f150 w/ a 302 EFI. I was checking some fluid levels and noticed the oil was in bad shape and smelled like gas. The previous owner used the truck at a mountain house only and had only put about 6k miles on it in the last 8 years. I looked at the last oil change and it was performed about 1k miles ago so who knows how many months ago that was. I immediately changed the oil and have driven about 50 miles and it still smells like gas. I suppose it could take a few frequent oil changes to clear it up, but is there anything else I can cheaply do to see if this fixes it before taking it to a mechanic? The engine seems to be running fine and I don't notice any strange noises. I was thinking maybe a bad spark plug coud go unnoticed and be the culperit.

 

You might have blow by on the rings. A compression test or leakdown test will tell you a lot.

 

ok, and so I'm somewhat prepard how much would that probably cost to repair assuming the worst that all piston rings are affected and while there in there may as well fix/replace them all? Just a rough estimate.

 

I would go ahead and go with a full rebuild kit which is roughly 400 bucks at Napa, or it was 3 years ago when I rebuilt my 87's 302.

 

Don't panic yet but get it to the mechanic. Gas in the oil could run your whole bottom end.

 

Yeah $400 PLUS labor if he doesn't know how to do it himself (and I doubt he does).

No offense to the OP.

If your rings are shot and you are getting that much blow by, you'll need a full engine rebuild.

It's hard to put a price tag on that, cause it varies so much depending where you take it.

If it were me, I'd compression test it and if they are all around the same PSI just run it. Keep an eye on the oil level and drive it until you have a problem.

My 302 has quite a bit of blow by lately, and I'm not going to waste any time or money rebuilding it. Most likely I'll swap it out for a 351W or drop an I6 in it for the kind of driving I do with it.

On the other hand, you MAY just have a bad O2 sensor and it's dumping in too much fuel....... It could be a lot of different things.

 

No offense taken. I don't know how to do it... would love to learn, but I know my current limitations. Sounds like I'll change the oil again in about 500-1,000 miles. If it still smells like gas, I'll take it in for a compression test and know where I stand from there. Luckily, its not an everday ride, so there is no major rush.

 

Could a missing PCV valve be responsible? I was looking over the engine the other day and noticed their was nothing hooked up to an opening/port coming off the throttle body. Would this be where the PC valve should be connected? I think I need to take some pics of the engine and post them on here and let everyone give it a good look over. From what I was told, the engine caught fire in 2001 and the owner just did what was necessary to get it into good working condition. Again, I'm no pro and want get offended if anyone corrects me on anything, just looking for a little help on this great website.

 

before you spend any thing,pull your spark plugs and inspect them.they should be a tan colour.black sooty plugs rich.plus this will tell you if you have a cylinder that is not firing properly.if that checks out another area to check would be the injectors.quite possible they are dripping under pressure after you shut the engine down.just dipping till pressure bleeds down in the fuel rails.your pcv valve should be on the passenger side valve cover at the back,and yes you should have one.it pulls the blowbuy gasses from the crankcase.good luck B.P.

 

Yeah, I bought some new spark plugs today and plan on replacing the existing ones regardless. I'll be sure to check each one and note which cylinder any suspicious ones come from.

 

let us know what you find.i just suggested the injectors because i have heard it happening.

 

as far as injectors go, would/could a fuel system cleaner/ gas additive possibly take care of that?

 

I am thinking a leaking injector too, but you will notice if this is a problem because the engine will crank a little bit longer than it should if it sits overnight. Have you noticed this?

 

Yeah, I probably jumped the gun on my diagnosis.

I always assume the easy stuff has already been checked and already taken care of before digging deeper.

 

Not at all, it generally fires right up. Idles fairly high for about 35-45 seconds and then comes back down to a normal engine speed. It will idle out if I drive it for a while and then cut it off and then crank it again with out giving it any gas, but I don't think this is a problem, just part of having an older truck.