'92 3.0 Rod or Wrist pin knock?
 

I've got a '92 with only 125k miles on it and I drive it very seldom
(a summer mountain toy only) but after 7 weeks of snow storms in
Denver, it's gotten a bunch of use (not a lot of miles, but hard ones),
and after I helped pull some cars out of a ditch one night last week,
and got stuck myself and so forth, where the truck spent a bunch of time
at an extreme angle, a day or two later I started getting a loud knock
under light engine load and throttle tip in. I checked, and the oil level
was low, either from running while it was leaned over a bunch, or that
just exasperated the problem, it appears that it became oil starved
and hurt something. I topped up the oil, problem is still there,
I drove it home and it's parked.

A mechanic who worked on my VW happened to hear it, and he
says maybe bad wrist pin, maybe something worse.

Anyone have experience with this? It idles quietly but rev it up
just a little and it starts clattering. Tip the throttle in from 1500-2000
rpms and it sounds pretty bad. Under load it's fine until about 3000
rpms then gets loud.. I know this is going to cost me a bunch of
money to fix, and I'm wondering what kind of damage I'm looking at.

ian

Mine had a slung rod bearing (rod knock), I layed under the truck when it was idling and I could tell it was coming from the crank area. Im not sure what the wrist pin would be doing though. I put in a remanufactured engine back in it. You can also have someone rebuild the bottom end and then piece the rest of the engine back together. I personally didn't want to deal with that.

hmmm i wrist pin or piston slap will get quite down after the motor warms up a rod knock will get louder.. sounds like a rod bearing

It's quieter when it's cold (thicker oil) and louder when it warms up
so I guess that sounds like a rod bearing. I threw in a quart of
Lucas oil stabilizer and it's had very little effect.

Assuming for the sake of argument that it is a rod bearing, is
there any way to replace them from the bottom without
pulling the motor completely out? Maybe just lifted enough
to get the oil pan off? Any estimates on what this job would
run me would be appreciated.

The stealership quoted me a rough $6800 to diagnose and
repair "rod knock", and then the guy had the balls to
ask me if I was selling the truck. Sounds like a scam if I
ever saw one.

ian

$6800...wow are they going to unscrew the radiator cap and cram a new truck in there?

6800 sounds about right for a NEW toyota short block and a head rebuild. You could get a jasper or somthing else not toyota and get out for around 4000 or more. You could try to drop your front diff and pull the oil pan, replaced the suspect bearing, might not last long though.

I'll sell you my 95 with a 3.4l for 5500 and take your old runner off your hands. Saves you the hassel of the rebuild and you get more power, then I have a truck to try a 1uz swap.

I'm interested. PM sent.

ian

I was quoted around $1000 to rebuild my bottom end. You can take down the front differential and drop the oil pan, and move the rods around using a the crank pulley to find out which one is knocking, but like someone else said it wont last long, because the crank is out of spec.

I've installed rod and main bearings on a '90 3.0 without removing the motor. You do have to drop the diff though. No real special tools required, other than a torque wrench.

Well, I ended up taking mudbutt's '94 3.4L swap off his hands
and he's got a new engine swap project. ;)

ian