Hey guys, I am pretty new to the classic car world and already having fun. A couple of months ago, I found a 1980 F-100 custom with 70,000 miles, so I had to check it out. It had been sitting on a deer lease for 3 years and fired right up with a set of jumpers and a little priming of the gas line. Originally a small town water district owned the truck so its as plain as you can find. However, my ford buddies told me that the 300-6 with a 3 in the tree was about as indestructable as they come, so I bought it. (Indestructable is a good selling point for me, I tend to break things easily)

The first step of the project was to unstick the brakes.... which failed when I found out that the brake fluid had turned to sludge. Long story a little shorter I decided to replace everything (master cylinder, lines, calipers, wheel cylinders)

Other things I have replaced:

ECU (correction, a friend chewed me out for calling it that since the truck in carbureted, but I still don't know what it's called... doesnt matter)
oil
oil filter
rotor cap
rotro button
spark plugs
spark plug wires
various light bulbs
pre-heater tube (emissions >_< )
tires
in-line fuel filter

items on the to-do list:

adjust the clutch
replace belts hoses (they still look ok for now though)
replace battery cables
adjust the valves (a little ticking right now)

the problem I am concerned about right now is the dummy light for the oil lights up at idle after the engine has warmed up. (currently using 10w-30) I'm thinking that a heavier oil might solve the problem since its freakin hot here in Texas right now.

If anybody knows something i should be aware of I will be taking notes

 

Umm, the oil dummy light only comes on in three situations, no oil pressure, faulty sending unit, and/or faulty wiring. You need to hook up an oil pressure gauge to the truck to monitor the oil pressure before you blow it. The 300 I6 is nearly indestructible, except when it has no oil pressure.

Also, the 1980 is a fun year to own, as there were plenty of changes in the wiring that separates a 1980 from a 1981.

Oh, and post pics!

 

The 300/3 speed stick is a rather tough combo. The *only* weakness is the shift collar on the top of the column. It is practically impossible to find a replacement when needed, so treat it easy and it should be ok for a while yet. It's prone to having issues if the gears are shifted too harshly, or there is something causing the gears to bind up.

As Shaun stated, that oil light coming on is a bit of a concern. Could just be a bad sender, but it would be a good idea to use a mechanical guage to verify the engine is making good oil pressure.

There are a few differences in the wiring for an 80 model, compared to the 81-86. Most are easy to deal with if needed.

10W-30 oil is a bit thin for the Texas heat, but it shouldn't cause the oil pressure to drop low enough to turn on the light. I highly recommend checking that out ASAP. Low oil pressure or low oil level will kill even the "tough as a boot" 300 in short order. So will overheating, so be sure to keep good belts and hoses on it, and it should be capable of going at least 200K without much problem, and could go twice that far......

 

I will post pics when I can, but for now I am headed back to the part store for the 1 socket size I am missing (so far). Thanks for the suggestions, I will be trouble shooting/ adjusting/ replacing stuff most of the weekend. (starting with a new oil pressure guage)

 

All I can say is Good Luck.

 

hmmm looks like i am way past due for an update...

since the brakes, i have have replaced:
rear main seal
flywheel
clutch/pressure plates
crankshaft roller bearing
topped off the trans with new oil

at this point i was happy they my clutch worked like it should (the old rear main was in bad shape aka pouring oil onto the flywheel)

then i noticed that after 3-4 miles the oil pressure would drop off and i could hear my valve train get louder

so i decided a new oil pump was in store... talk about a royal pain my back side

i get it all back together to figure out my water temp guage and possbly my thermostat are bad... i was in the middle of nowhere on my oil pump test drive when the oil pressure dropped off so i drove a little further to a friends house to let it sit and cool off during the football game... popped the hood just in time to catch it boil over a little bit (less than a cup over flowed. the whole time my temp guage was telling my the water was cool.

so now i get to flush or replace the radiator in addition to the water sensor/ thermostat....

advice is always appreciated...

i was wondering if anybody knows if the gears on my 3 speed are strait cut...

 

your problem may just be in the thermostat and temp sensor. but if there is not enough water in the truck it will not give you a correct temp reading. always make sure you allow the truck to warm up and allow the thermostat to open to make sure that it is full.

 

This should be interesting, and as Fordzilla stated, the '80 is definitely a fun year to own. Haven't seen too many with 3 on the column either. Definitely subscribing to this thread. Good luck!

(btw, my brother succeeded in destroying the near indestructible 300 in our old '83, trying to run it like a it was a race car. Just keep up with the maintenance as you're already getting a good start on, and don't abuse it too much, and I'm sure it'll last for many years and miles to come!)

 

Since you're having coolant issues, this bit of advice is warranted.

DO NOT run tap water for coolant. Or else:

 

Ouch, Fordzilla...

 

It also comes on with the ignition switch to check the light before the engine starts. If the ignition switch was sticking, there is a possibility of the Brake, Oil and Alternator light being on, and your radio and wipers not working etc...

They are the one year wonder for different parts, I will say that.

 

Might be a "1 year wonder", but there's ways around that, as proved by me sucessfully installing the 81-86 tach cluster in my 80. Extensive re-wiring was needed (swap #17 & 18 in the connector) and the later cluster bezel to match the later cluster. Yes, it really is THAT simple when you have a guage cluster 1980 model. Best of all, the hi-beam indicator doesn't blind me anymore.......

 

got it... no tap water...

as per usual it has taken me a while to get back to replying to this thread... i decided to go have the radiator flushed for $55 at a local shop (which does really good work). as it turned out, they couldn't pressurize the system because of (probably) a blown head gasket. they don't do that kind of work so i took it home and prepared to pull the head to take a look. to my dismay, one of the head bolts was barely snugged down. (the bolt all the way against the firewall on the passenger side).

after consulting an older car enthusiast, i was just going to put the new gasket on and drive it until it quite (while saving up for a crate engine). i didn't come to that conclusion over night... i assure you we went through the very numerous possibilities for getting a little water in one of the cylinders w/o actually blowing out the gasket... i spare you the 10 page thought process.

i then told him about the oil pressure drop after 1 mile of driving. (this continued after putting in a new oil pump). he then told me that more than likely the previous owner had gotten some water in the oil and the main bearings were going out. since it didn't knock and ran pretty smooth given the oil pressure issues, he figured that the crankshaft was still good and i just need a "poor mans rebuild"

last night i finally had all my ducks in a row to yank that bad boy out... my shoulders sure were sore this morning lol.

keep any and all advice coming... i do check the forums for info, i just get too lazy to log in and post very much.







enjoy the much overdue photos

 

A poor man's rebuild is why my 300 is headed to the scrapyard. lol.

Regardless, I have extra 300 parts if you need them.

 

Thank you for the advice. I kept what you said in the back of my mind along with the advice I was getting from my buddies while I was tearing the engine down.

I don't have very much time to go into much detail right now, but I do have an update coming soon with pictures