Hey guys, just rebuilt an engine and threw it in and was noticing I was getting odd vacuum readings, was only getting about -12.6 at idle. Car drove fine for initial break in drive getting up to 0.0 but i cut the drive short due to finding that reading odd. I will do some more in depth looking around for vacuum leaks tomorrow but was hoping for a sanity check. car starts and idles fine, timing verified with light. or am I over thinking this for the initial break in?

 

Gonna need a lot more info to really be able to offer much insight; is this a turbo motor? Stock rebuild? What units are those numbers you’ve mentioned? In-hg, kpa? What management are you running? Has it been tuned? What necessitated the rebuild? What was your break in procedure before driving the car?

 

rebuild is a turbo motor, machine shop decked the block and head, line honed balanced the rods and pistons, bored it to 83.5mm for a 8.5-1 compression ratio piston, manly rods stock head but with volvo valve springs, boundary oil pump, arp studs allround and a fluidamper. turbo running is a 6258 that was on stock low pressure waste gate. all running off of a MSPNP pro 3. I am just realizing that it might have been reading in psig. and that might have been my problem

 

If the car starts, idles fine, and the timing is spot on, then the odd vacuum reading could just be a normal quirk, especially during the break-in phase. Turbo motors can behave differently when they're first fired up, and vacuum readings might be off depending on how everything settles. The reading being in psig could definitely explain the confusion. Check for vacuum leaks when you can, but overall, it doesn't sound like a huge issue yet.

 

it ended up being my passenger was reading from the laptop in psig, my boost sensor that read it hg was not working due to knicking it with a file so i was flyin with just laptop fot the first run. Pulling around 24-26 hg on coasting and at about 19hg at idle right now with about 250 miles on the engine. Starting to get into wastegate boost. Only issue now is i know i have oil pressure but i dont know the exact amount due to the sensor getting heat soaked so my oil pressure goes up as it gets hotter.. when i turn the car off it shows up to 30 psi still.