Boatman

Just bought an 86 4 Runner with a knock in the motor.

The longer it runs, the less power it has. Compression on all 4 is 125psi. Dont smoke.

I tried to drive it home last night, the further I went, the slower it would go. Possibly a main bearing or a rod bearing seizing?

The killer is, the noise sounds like its coming from the top side. Not he dull iron clanging sound of a rod. More like a lifter, but its overhead cam, and everything looks good. Besides that, if it was a lifter it would have a miss. It starts and runs really smooth, except for the knock.

What I am asking is.... before I pull the motor, does it sound like a crank or rod bearing? It does to me, just wanting a second opinion.

Thank you,
Pat

Also is ther a trick to removing the EFI withou having to unhook ALL the hoses??

flecker

125 psi is pretty low across all 4.... should be upwards of 170-180. The sound on the top... is it like some rattling??? Or a constant tapping??? Whens the last time you adjusted the valve lash? Sounds like a dinged valve from your description, that doesn't explain the low compression though. Have you had any head work done lately??? need more info...

Boatman

I just bought the truck the other day, so I really dont know much history of it. Only gave $300 for it. Good A/T rubber all the way around and everything works! Just a little rusty, which I believe to be common, it sure is on my 88 Toy pickup anyway!!

I tried to drive it home the night I bought it (acrossed town) and made it about 1/2 a mile and it was banging and rattling so bad, I was afraid a rod was going to go right through the pan. I lost power to the point that it wouldnt hardly get acrossed an intersection, so I parked it and dragged it home the next day.

Currently the motor is hanging in the shop, I went ahead and pulled it today. Man the top two bolts to the tranny are a pain.

I am going to drop the pan tomorrow to investigate. Then I will go from there.

Any words of advice form anyone at this point would be great.
I have rebuilt countless outboard motors and all other types of small engines. I reckon this one wont be too bad, as it dont have needle bearings on the crank and rods like an outboard

Thanks a bunch!

Pat

JustAnotherJodieFE

I just finished rebuilding my 22RE with good results for the most part. I had installed an aftermarket RV cam, with new springs & rockers. This was my only mistake. The cam & rockers just wore into each other as if I didn't have any oil in the thing (which of course I did). The damn thing only had 440 miles on it. Anyway, I changed back to the original cam & rockers today. Runs much smoother & quieter now.
There's a seal on the underside of the intake manifold that didn't come with the rebuild kit. It's the one from the metal tube running around the back of the engine. This was my only leak (coolant) when I first started it up!
EFI intact? For the most part you can leave it together, but it's a pain trying to handle the whole thing without bending or breaking something.
Make sure you get the block bored out real nice and replace your pistons. I took a machine shop's advice last year and just replaced the rings without boring it. Big mistake!! That's why it's got another rebuild a year later.
Any questions, just ask me.

Pete

JoKEpLaYeR

What rebuild kit did you use? and would you recommend it?

Thanks,
Steve

JustAnotherJodieFE

I used one ordered by the machine shop that did the work on the block. I can't recall what the brand was right off. If I remember I'll reply.

Pete

JoKEpLaYeR

Thanks.

I'm thinking of going that route too.

Steve