A friend of mine recently picked up this 1994 F-150 XLT (4.9 straight 6, E4OD, 2WD, shortbed), so I met with him over the weekend to wrench on it a little.
This was our second weekend poking around on the truck. Last time, we replaced the belt and tensioner pulley, which was making an absolutely HORRENDOUS screeching noise. This was right at the top of the list, because you just couldn’t hear yourself think any time the engine was running.
We also tackled a problem with lukewarm cabin heat. The coolant was brown (but no oil contamination), so we proceeded to rinse the cooling system. He had forgotten to get some flush additive, so instead of going into town to get some, we just went ahead with a multi-stage rinse. We drained and refilled it with tap water, then ran the engine for half a minute before doing the same thing all over again. We got most of the old coolant out (some always stays in the block), and made sure to use distilled water for the last couple of rinse cycles.
Before final fill with coolant, we replaced the thermostat with a new stock-temp one, and removed the surge tank. With the surge tank disconnected, we slipped a couple of short chains inside and shook it up with some water to clean it up. The inside was coated with a brown film that was making it hard to read the level. At one point, I had to use a long screwdriver to pick at the bottom of the tank to break up a clay-like sludge. Yuck.
After reinstalling the surge tank, we filled the system up with coolant and bled the air out. There was an immediate improvement in the truck’s ability to warm up the cab. Success!
Fast-forward to a few days ago. The truck’s heater had gone back to kicking out lukewarm air again. And having put a few more miles on the truck, he now had a shuddering that he hadn’t noticed before on his test drive.
So we met again, at a mutual friend’s place (the guy with the DIY hoist) and wrenched on it again. Knowing that Fords of this vintage seem to be particularly sensitive to the type of fluid used (using the wrong stuff is known to cause shudder), and that this truck’s fluid was brown and in need of changing anyway, we put the truck up in the air and got started.
We pulled the pan (no drain plug) and drained the fluid out. We also turned the engine by hand to line up the torque converter drain plug to empty that, too. There were signs that someone had been in here before. There was no dust plug rolling around in the pan, and no reusable OEM gasket to avoid using the crappy flat gasket that was part of the new filter kit.
So to increase our chances of not ending up with a leak, we set the gasket on a flat surface with some weight on it to straighten it out (it was kind of bunched up a little in the box with the new filter). This would help keep the gasket from shifting while moving the pan back into place. Meanwhile, we cleaned up the pan and magnet to prepare for re-installation. (The magnet had collected about half of its own size in tiny metal shavings. No larger chunks, though.)
We cleaned up the bolts and carefully put the pan back in place, ALMOST forgetting to put the new filter in place lol. But we caught it in time, and made sure that the old filter’s O-ring was removed from the case bore.
These cheap flat rubber gaskets can be really hard to seal, so I let my OCD run wild on tightening the bolts. Treating it like a head gasket, I snugged up the bolts then went back around tightening them in three stages. I started by tightening all bolts to about half-spec, then I set the torque wrench just a few lb-ft tighter for a second go-’round. Then I tightened them all up to 14 lb-ft (spec is 12-15 for the flat gasket, less than that for the reusable one). Upon refilling with Dex/Merc, we’re not seeing any leaks, so I’m pretty satisfied about that.
But before lowering the hoist, we took a good look around the rest of the underbody. It’s a good thing that he was able to talk the seller down in price, because the front fuel tank has a small leak. Hard to tell where it’s coming from, but it seems to be from higher up, so until he’s saved up for a new tank, this one will only get filled half-way.
But a temporary solution like that isn’t going to help with the other leak we found. The oil pan is leaking from the gasket, which is actually hanging outside the pan about 1/2" or more in some spots.
He’s decided to let a shop handle that job, and it’ll be taken care of later this week. Good thing, too, because there is a whole section between two bolts over by the starter that has slipped out and is hanging by a thread. I suggested that we could wipe the exposed gasket clean and loosen the bolts a little to slip it back in before tightening them back up again, but he’s too nervous to touch it. That would be just a temporary measure anyway. It needs a NEW gasket, and it needs it ASAP.
As near as we can figure he’s lost about a quart in just one day of driving! He’ll keep topping it off as necessary, but will avoid driving it as much as he can until it’s time to take it in for repair.
And as for the heat that went lukewarm again? We disconnected the hoses going to the heater core and flushed it with a garden hose in both directions. Some sediment did come out, and after hooking it back up and refilling, the heat kicks ass!
This poor truck has been neglected in some ways, but the previous owner did at least give it some new shocks and brake lines. At only 147,000 miles, it’s good to see some new life being breathed into it.