The Problem: I hear a ticking noise and my oil pressure is around 20 psi when idle, but goes back up to 40 psi when I accelerate.
(Still learning about this truck and engines in general so bear with me)

The History: Car was given to me with a motor that a huge freeze crack in it. I got another motor from a junkyard and thus have the problem above. It seems to run fine when its cold, only when it is hot is when the problem arises.

Any suggestions to fix or just get a new motor?

Thanks

 

All the blazer oil gauges do that, I thought I had a problem when I bought it but was assured otherwise by a gmc tech.

 

yup ditto.....common thing.
mine taps on cold mornings for along time...i fixed that by adding lucas to the oil changes and the ticking went away...i chalked it up to noisy lifter.

but yeah...higher temp = lower oil pressure esp at idle....looks like yours is running in the ball park.

 

So the semi-rough idle is normal? And it wont hurt the truck if I drive it as is?

edit: The ticking is not on a cold start, it only starts happening after the engine heats up.

Thanks for the quick replies ^.^

 

rough idle how? that wasnt in first post...
check your plugs and wires...any codes?

could clean MAF sensor with some maf cleaner it comes in a spray can..easy to do.
could be several things with an idle issue

fuel filter even...we need some history then.
did you put new plugs in your swapped engine?

 

Seafoam it, makes a world of a difference if it's just carbon build up.

 

all that stuff for my rough idle i did.... plugs, wires, ign components, oil, cleaned maf and iac valve.... ive determined that the solution could only be the unholy (( SPIDER )). iv e ordered the new spider and gaskets and will install as soon as they arrive... it evolved from a lil rough idle to a lil mini misfire pop every now n then. the plugs and the fuel filter are a year old ... the fuel pump is a year old... ill change the plugs and the filter when i do this repair.. then... oh baby then i hope this idle issue is completely gone. ... i pray to the blazer gods that it will be the solution...

 

Rough Idle as in, sittin at 20 PSI rough, i think my bearings might be going bad inside the crankcase (i believe that is what its called) I might have to send them to a machine shop. Im still on the case of low oil pressure. i think the ticking might be a small "knocking" noise instead of "ticking" due to my inexperienced ears. I might have to end up getting a 3yr/100k mile motor in a box which would be awesome

If I end up having to get a new motor you guys know what to put on it before I throw it in to get a natural increase in HP?

Edit: No codes at the moment, also noted when the motor is drivin about 15+ miles the oil pressure doesn't even go above 40 PSI anymore, so its steadily declining as the motor gets hotter. As you said before hot temps kill the pressure cause it makes the oil so lubed up (rofl). Which makes me refer to the bearings inside the case.

 

Goodluck!

 

Your talking about the Rod bearings. And it don't sound like them. Your oil pressure will be fine and as it get warmer it will drop like a rock and lower then 20 psi. I had one do it (67 GTO) the oil pressure was fine at the start but by the time I got home (Appox 20 miles) while driving it would drop to almost zero. At a stop it stayed at zero. I change out the rod bearings (All of them and check the crank for a any damage) and the oil pressure was fine and did not drop to anything like that.