I am a retired truck mechanic. About 5 years ago I sent my 1988 ford f250 out for a complete motor over haul because of a bad rod nock. It now runs great. The problem is that maybe 1 out of 3 starts the starter hangs up and keeps running. This particular model does not use a solenoid on the starter, all the amperage goes right through the fender wall mounted relay. This is a fairly common problem on this model. I put in a heavy duty battery and up sized all battery, starter and ground strap cables. This is the normal fix to reduce amperage draw. No change to the problem. I seldom use the truck and in the past 5 years have less than 100 miles on the newly over hauled engine. I recently came to the conclusion that the engine is turning over slightly slower than it should because it is tight drawing excessive amperage causing the starter relay contacts to weld together.
Here is my dilemma. I am debating if I should go for a slicker less friction oil or go for an oil that would allow the engine to break in quicker. Opposite jobs here. I have never overhauled an engine in my life and had it tight when I was done. I consider that a defective overhaul. I am thinking maybe a break in type oil for 1,000 miles and then switch to a high grade oil. I have never really dealt with this before.
Mainly a power generator mechanic from the military contributing here, but when you use the break in oil, is it possible to purposefully put more miles on it than you are doing, or to get some load on it, like putting weight in the bed, and driving it in a hilly area? I’m just thinking that if you are using the break in oil, in might not keep everything coated between uses if you use it infrequently, so you might want to do something that breaks it in faster.
That is what I had in mind, making it my primary transportation for a few months. I just have no experience at all with break in oil and not sure what to expect.
If you have a truck you are putting less than 20 miles a year on all kinds of things can go wrong with it if not used. If the truck has value and has an overhauled engine why not just drive it a bit to get rid of the tightness problem and then sell it. Between insurance and registration and now repairs it’s costing you hundreds for something that yields almost no utility based on your current amount of use.
In my mind I keep thinking I want to start driving it. The older I get the less I need a truck. Selling it is my best option. I don’t want to see it with a tight engine.
is the starter new? Fords of that era with the remote (fender-mounted) starter relay used a movable pole shoe starter. it might be the starter simply failing to disengage.
Have you checked the starter alignment? I only have experience with Chevys, no Fords, but the symptom of a starter that is too close to the ring gear is sticking (too far away and it’s noisy).
This type of starter doesn’t keep running if it hangs up, only a stuck relay can keep it running. Relay is drawing too many amps, no doubt here on what is happening.
Pardon my relative ignorance, people here get angry with me when I make suggestions or ask questions. But if the relay is drawing too much current and sticking as a result, wouldn’t adding a resistor to the circuit help resolve that problem? That’s what we did with the now ancient copiers I worked on, which used electromechanical relays.
The relay itself is not drawing too much current, it has too much current passing through the relay. I believe it is rated at 150 amps. I need to check that. A tight engine or any factors that make an engine hard to turn over can easily nearly double the normal amp draw. I am considering retarding the timing a few degrees until it breaks in.
Because when you turn the motor off it keeps running, I did this for a living for about half of a century. My question is not about whats doing it, I know whats doing it. I don’t know much about break in oils is my main question.
I have not physically seen your engine nor been there when it was built so i cant say i saw them gauge the crank after machining, but it almost seems that they may have turned the crank too tight?
I doubt it’s just binding the starter, i think you’d know that since you already replaced it you’d have seen the gear taking horrendous wear and stuff.
Problem is, i don’t know of any reliable fix for that except pulling the crank, measuring it, then polishing to proper spec.
I have also seen this happen when someone put bearing caps on backwards.
Motor was god awful tight, good thing we torn it back open to see why.
In any case, problem is if the bearings are too tight, wearing them in might result in nearly shot bearings before the engine has the proper looseness Or a worn/damaged crank.
I think I got you now. Your problem is that the engine bearings aren’t as they should be, and that causes the starter motor to require additional cranking power, which in turn pulls excess current through the relay, rapidly causing the relay to wear out and stick.
That would mean that solving the tight bearings is the real concern. But if you wanted to try just waiting for the bearings to “loosen up,” you could temporarily add a resistor to the starter circuit, then take it out when you think the engine is “loose.”
Or a worn/damaged crank.