I really need help on this one! I have a 92 F-150 Nite with an FI 302. I have oil in my radiator! There is NO water in the oil! It idles fine but, the temp gauge doesn't get as high as usual and sometimes if I slow to a stop, it will instantly drop to nothing. I discovered the problem when my gauge started acting strange about 300 miles from the house at Christmas. I checked the radiator first thing thinking I was low on water. I noticed the oil but, had no choice but to chance it and drive it home. I could tell it was hot on the drive home but, it never had any knocking or signs of problems. When I checked the radiator after I came home, it had a lot of oil in it but, still no water in the oil. The local mechanic seems to think it's in the block which is what I thought myself. If this were my old 68 fairlane, I would have already yanked it or at least pulled the heads but, this motor has no room to do anything! The engine has A/C with a manual 5-speed so, it's not an oil cooler. The truck has all options except 4-wheel drive. Am I going to have to get a new engine? If so, who do you recommend for the best prices? I thank you in advance for any help you can provide!
John

 

I cannot tell you how dependable these motors are but autozone.com or your local autozone is listing 351w longblocks for $745 after core. Not a bad replacement price and comes with a warranty. A 302 should run around the same money or may be a good time to upgrade to the larger small block, check it out. If the truck is otherwise in good shape and you don't have a lot tied up in it then this may be a route to take. Good luck

 

Sounds like it could be a head gasket. I would check compression first and make sure you are getting decent compression in each cylinder and that they are within about 15 percent of eachother. is there any white smoke comming out of the exhaust that could be coolant burning? You cant go wrong taking it to a good mechanic and asking his opinion though.

 

If you haven't done a compression check yet, I would absolutely agree that that would be my first step. If that turns ok I'd drain the coolant and flush the system and see how that looks, short of those two easy checks I'd also be concerned that the head gasket is busted or the block is cracked. Good luck and keep posting you'll get the help you need.

 

I greatly appreciate the responses! I took it to a reputable mechanic who conferred with other local mechanics and they came to the conclusion it was somewhere in the block. The only white smoke is the usual during cold morning warm-ups. My big question is about the make-up of the head gasket area. It has been about 12 years since I really did any work on car engines. After I sold my Fairlanes, I started dealing more with motorcycles. I can't remember if there is an area where oil can make it into the water jacket around the gasket area. The only oil flow in the head is from the pushrods so, there is no pressure to overcome the water pressure. Correct? The coolant return reservoir has never worked properly (1995-now). It always drew from the reservoir but, never returned any. The engine has always run great until Christmas.

 

 

Check the rad, sometimes the transmission fluid that goes to the rad in the cooler lines for cooling gets into the rad and antifreeze check for redness.