20r Oil pressure drops once warm

[Box5]

So I finally found a flatbed toyota with the 20r motor that i'm looking at buying, but became aware when warm, the oil pressure gets fairly low. Worn bearings? Or maybe something simple?

I'd like to go there with alittle more info. I wouldn't mind having to do a engine swap, but i'd need to get the truck for a cheaper price if this problem is a serious bottom end one.

Thanks

 

[Pook]

Whats fairly low # wise? and whats the oil look like?

 

[body damge]

80w-90 :fawkdancesmiley::fawkdancesmiley:

 

[Box5]

lol. I was checking over craigslist, and theres a few 20r motors complete in good running shape for $200. So maybe I get this for cheaper since it will need something, and run it into the ground, then do a swap. In the meantime...heavy weight oil?

 

[sj-x 500]

my 22r starts and idles at 40 psi for a while, once it's warm it's under 5 psi. a few people tell me it's normal...

 

[crash2]

Normal..........

 

[WHITE TRASH1]

Normal for a really high mileage engine or one that's been beat to fawk....

 

[crash2]

Min oil presure is 4.3psi per book specs

 

[WHITE TRASH1]

Min oil presure is 4.3psi per book specs

Yea and a big block chevy will live with under 7psi but that don't mean it'll live that way forever. :haha:

 

[datsunon40s]

my 20r that I BEAT for 4 years ran at 18-20psi at 800rpm at operating temp:awesomework:

even so easy $50 fix pull the pan and put some rod bearings in it:awesomework:

 

[nevada]

my 20r that I BEAT for 4 years ran at 18-20psi at 800rpm at operating temp:awesomework:

even so easy $50 fix pull the pan and put some rod bearings in it:awesomework:

id throw a new pump on..its probably weak...and with low oil pressure..that lets the chain run looose....thats BAD. oil pumps on those are EASY, since theyre outside the engine.

also, it wouldnt hurt, as suggested, tossing in a set of rod bearings. if ur careful, u can swap out the mains too. ive done it:awesomework:

another thing....the pressure valve, on the side of the pump. might be able to pull it, and put a thin washer underneath the spring. i think thats right..add a washer... or was it remove the washer thats there? crap..i dont remember now...anyone?

 

[WHITE TRASH1]

You add washers under the relief valve to up the pressure.

 

[datsunon40s]

id throw a new pump on..its probably weak...and with low oil pressure..that lets the chain run looose....thats BAD. oil pumps on those are EASY, since theyre outside the engine.

also, it wouldnt hurt, as suggested, tossing in a set of rod bearings. if ur careful, u can swap out the mains too. ive done it:awesomework:

another thing....the pressure valve, on the side of the pump. might be able to pull it, and put a thin washer underneath the spring. i think thats right..add a washer... or was it remove the washer thats there? crap..i dont remember now...anyone?

oil pump for sure ... and its a given when you do rod bearings you put in a new pump just forgot to mention it thanks:awesomework:

 

[Box5]

Thanks for the fast responses. Im going to check it out in the morning, with any luck i'll have it on some jacks in my garage tomorrow to undergo surgery...

Edit: Ended up picking it up this afternoon for $1200. I was looking for a stock truck to build from, but I couldn't pass this one up since it was local, and in decent shape. Problems are it pops out of reverse sometimes, and the oil pressure drops to around 8-10psi once warm at idle. Cosmetically its in decent shape, but im gonna do a bunch of rust repair in small spots anyway. Eventually get rid of the wide tires and go to some 33x12.5 km2's. Build some side stakes for the bed to haul firewood around our property. And once either the trans or engine dies, hopefully do a 22re swap, and deal with a gearing overhaul.