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4x4van's avatar
4x4van
Explorer III
Sep 08, 2015

Seized Onan...rebuild or replace?

My old Onan 4KV (4.0 BGE series) generator seized up while running down the road (running A/C). Oil level was good, never had a problem running it while driving before, but... Won't even start to turn over; locked up tight. Pushing the start button (either remote or on-unit) gives a click only; battery is good.

Am I better to have it rebuilt, or replaced with a newer model? Or am I missing something simple? A first glance appears that it would cost around $3000-$3500 to replace (w/ a 4.0 Microlight CA). Ouch! Any more cost effective ideas?

17 Replies

  • 4x4van's avatar
    4x4van
    Explorer III
    Thanks for the quick replies. Don't know about any noise when it stopped; we were driving down the road with the A/C running, suddenly the A/C stopped. Went to the rear (where the Genset is located) and verified that it was no longer running. I'll see if I can get to the fan bolt to try to break it free.

    Can't remember the hours on it, off the top of my head; I'll check that when I get home from work. It's the original genset in the MH (I think, anyway), and we really don't use it alot, other than going down the road when it's hot since the dash air just can't cool the entire coach.
  • Rather than rebuild it, I'd just get a newer inverter generator (or pair with parallel cable) of similar size (and likely less cost) and use the Onan's compartment to store the generator(s) when not in use.
  • # hours on unit? If it's high time.... I'd replace it. Might replace it anyway and get better technology and design.....

    T'would be quicker ....
  • If you do have to replace, PPL will probably be the cheapest at $2900.

    I would definitely get it looked at first
  • 4X,

    First, Do not go to an Onan dealer. Go to a small engine shop. Pay them to do a diagnostic and quote a repair.

    Then and only then, decide how you want to continue. If it had oil at level, it may well have been a piston seizure, and if that is the case, repair may be only several hundred dollars in parts and probably 1K$ labor.

    If it was, you have to also find out why it wasn't cooling effectively.

    Matt
  • A suggestion on the off chance it may help....

    On a trip last year we shut off our Onan without first shutting off the A/C load and allowing the Onan to run for a while to cool down. The next time we tried to start it, it was seized. With our Onan Microquiet 4K, it is possible to reach in and turn the cooling fan by hand. I tried this with no success, but fortunately I had a socket set with the right size socket to fit the fan bolt. It took a bit of effort, but I was able to break it free and it has run fine ever since.

    If you try this, make sure no one tries the remote start while you have a hand or tool near the fan.
  • It depends on how much you can spend. I would look into having an independent engine shop give you some options, a dealer, nope. They will farm it out and add their cut. Any local shops that are in

    your town would be my first stop. Possibility something jammed the engine or generator causing it to not turn. Did it make noise before or just stop or just fail to start? Could be the starter. I have seen

    fan blades break and jam onans but they were big underslung units for trucks.