Privacy guaranteed - Your email is not shared with anyone.

Need some automotive advice

Discussion in 'The Lounge' started by BigJohn, Aug 4, 2005.

  1. Jumped in my truck a couple of days ago, and I think the motor seized. Turned over a couple of times, then a "bang" and now it won't turn over at all. I think the starter is getting plenty of juice as the positive battery terminal gets hot (to the point of smelling) if I try to turn it over a few times.

    I have been having a problem with low oil pressure at warm idle for the last few weeks. I wasn't too concerned as web research showed that typically wasn't a problem in older vehicles as long as it was only at a warm idle. Pressure came right back up with a very small increase in RPM (taking the truck out of gear would bring it back up to normal).

    The truck is a '98 F150 with the 4.2 V6 motor. Has about 120K miles on it. I got it at 100K and now think that it probably wasn't maintained very well before I got it. However, other than the motor, it's in pretty good mechanical shape and no rust.

    Not sure what to do. Checked the price on a couple of places to install a new or rebuilt motor and it's between $3500 and $5000. I really don't need or like that big of a truck and am thinking of just putting that money into a newer Ranger. Complicating the problem is the fact that this is my vehicle used for work, so I'm having to borrow a vehicle until I can get this worked out, so I need to do something rather quickly.

    My questions are:
    1. Does my assessment of the problem sound accurate? Are there other things I should do to confirm it?
    2. Are there any cheaper alternatives to replacing the motor (I'm kind of mechanically inclined, but not set up to do a full engine swap myself)?
    3. What kind of price could I expect to get on the truck to sell it "as is" and what would be the best way to approach it?

    Any other suggestions are welcome.
  2. My brother had a 98 F150 with the V6 and had an engine seize on him. Come to find out that that model of engine is know to have an antifreeze leak into the oil.

    A low oil pressure at idle condition is an indicator of loose (worn out) main bearings.

    It is slightly possible that the started motor is what is siezed. It's worth checking. Put a large ratchet and socket onth the crankshaft pulley and see if you can turn the engine over by hand. If you can turn it over, drop the starter motor and test it on the bench. If you can't turn the engine over then it's most likely siezed.

    You can also get into a situation where the engine is what is called "hydro-locked" Where there is some sort of liquid (antifreeze) in the combustion chamber. You cannot compress a liquid so it affectively locks the piston from moving up in the chamber. This can be tested by removing all of the spark plugs and see if you can turn the engine over.

    All that being said, I just reliezed you said you heard a bang then the engine would not turn over. Take a look under the truck at the engine and oil pan area and see if there are any torn holes in the block or oil pan.

    Also pull the dipstick and look at the color of the oil. If it's black, fine, if it's the color of peanut butter, then there is water in the oil and the engine is most likey trashed.

    You can also look in the radiator and note the color of the antifreeze.

    Taking into consideration you heard a big bang, I would venture to guess that you broke a connecting rod and it is wedged in a fashin that is preventing the crankshaft from turning.

    But I have been known to be wrong from time to time.
    Good luck

  3. Doe sthe engine turn over by hand? Loud band???Was it running??
  4. UFM82

    UFM82 The one others want to be

    When you say "it turned over and went BANG" do you mean it started, ran and did that? Or was it just cranking over. Just to be certain- tell me if it was a "cranked but did not start" or was it "cranked, started and then quit." An engine normally won't "blow up" just while being cranked- not enough energy happening just yet. However, once the engine is running, anything can happen.

    Can you turn the engine over by hand? Get a socket and a breaker bar and see if the engine can turn. If it is "locked up", it could be internal OR external. It could be ugly like a rod or a seized bearing or it could be not so ugly like a broken timing chain or even a broken starter. Without seeing it it's hard to guess.

    See if the engine can be rotated. If so, check the starter for damage. If not, it's gonna need some internal work for certain.

    The truck is worth about $5K with no engine and maybe less. The V6s are not real popular in the F150s. If the rest of the truck is in good shape and you think it is worth it, spend the cash to fix it. If not, ditch it use the money as a down on something else. I almost always think that fixing it is cheaper than buying something else nearly every time but sometimes it's easier to just get something else.

    Good luck.

  5. UFM82

    UFM82 The one others want to be

    you guys are too fast for me. Yea, what they said. LOL

  6. Boy you guys are quick. Thanks for the responses. More information:
    The "bang" wasn't real loud, more like a "thud". The motor had not started. The thud happened at about the time it would normally have started, and it sounded like it was going to start and I was letting off the key (the motor normally started fine). As a matter of fact, I thought maybe it had backfired through the intakes when it first fired. Now when I try to start, you can hear the starter start to move like the bendix is activating, then it stops. After a few trys, the battery terminals start to smell hot. I did look at the oil and it looked fine. There is some evidence of oil in the antifreeze, but it has also been loosing some antifreeze, like a head gasket was leaking.

    I'll try to find tools and turn it over by hand this evening.

    UFM, 5K with no motor? I had no idea it would be that much. I was thinking more like 2K or maybe less.
  7. shadowman

    shadowman Supreme Being

    yeah try turning it over by hand, its kinda hard to imagine it would seize up that way, now if you were driving around with no oil or oil pressure than ok but if the motor has oil and oil pressure........i would look more to a broken timing chain or maybe it threw a rod........don,t panic i don,t think your going to have to replace the motor....................... :D