NAFC

so as i was driving to work at about 70/75 in 5th, there was a sound similar to backfire under my hood n my car suddenly began slowing down and also started to sound more and more like a lawnmower as the seconds passed. it eventually got to the point where i had to go to third to get enough torque to make it up to the nearest offramp.



my engine didn't have more than 134,000 miles, thus blowing could be a premature death.



i pulled over and towed it home to be safe, i didn't want to end up having an apex seal damaging my inner housings any further while driving it home (if i drove it). if the case was oil deprivation then running it anyway wouldn't be too great for it either.



anyway, at home i ran a few test. all 4 spark plugs are firing, crank angle sensor checked out good, nothing electrical is out (such as my BAC or selinoids n whatnot), im getting fuel and air because im able to still start my motor (plus i got a new fuel pump). the only problem is that it has absolutely NO ***** and it sounds horribly like a lawnmower.



we took off the exhaust and looked inside at each individual seal and they all checked out OK. they all made the crisp sounds of working seals too. along with a visual inspection we used a compression checker and my PSI reading was up to 120psi, and on the bounces it went down to 60. it did bounce 3 consistent times as it should've, it just bounced up incredibly high. ironic since u normally have to pay and build a motor to a higher compression..(haha..pun). later on we checked my buddy's compression and his bounces only went up to 85-90, the exact reading specified by Mazda (on a rebuilt/working motor).



my car also idles really low after blowing whatever it blew, but turns on just as easy as it used to and stays on. my car's heat also shot up to about 3/4 on the temperature guage, but thankfully there are no signs of coolant or blown coolant seals in the exhaust.



there aren't any vacuum leaks since i've taken off the rat's nest and blocked off my EGR, along with the other various smog components commonly removed.



so0o0o0o0o0o i'm stuck. i have absolutely NO clue as to wtf could be wrong. =[



any suggestions? anyone?

ill_booger

You said your temp shot up (oil makes up a third of the enigne cooling). I would check the oil (level, OMP if you have it) If it's an S5 and your OMP went bad, it will go in to a limp mode. Thus lacking power.

rx7ahh

omp? are you talking about the oil pump?

ill_booger

No. Oil Metering Pump or Metering Oil Pump, same thing.



Below are links from the Factory Service Manual (FSM)

S4 Lubrication System(S4's have a mechanical OMP)



S5 Lubrication System



Hope this helps.

BoneT2&Harmony

same thing happened to me. Replace the plugs and wires, even if they look good.

DarkFC

Wait so... What were those compression readings? If one of the faces were 60 sounds like you got problems... maybe im just misunderstanding. Also do what these other guys have been saying.