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95 Toyota Tercel low compression after replacing piston rings. So after I replaced the piston rings and bearings main and rods compression is at 90 psi and 100 psi. A wet check the compression goes to 105 to 135 psi the block was sent to a machine shop I was told that it's within specs. The pistons rod's had to be shaved crank was just polished.
I installed pistons npr brand oil rings at bottom ring #2 in the middle ring #1 on top.What I did notice was that the thicker ring was the #2 ring and not the #1 . The rings have marking on them i put them facing upwards.
I need directions on what my next step should be before I tear the engine apart thank you very.
It sounds to me like a valve sealing issue, however did you hone or glaze-bust or even just roughen-up the bores with abrasive cloth before you renewed the rings ?
For new piston rings to break-in the surface of the cylinder bore has to have the highly polished wearing surface cleaned off to leave a surprisingly rough texture to which oil will stick and enable the piston rings to break-in (run-in) and form a good seal against the cylinder wall.
Only way to get a better idea if it a valve or piston ring problem is to do a cylinder leak-down test, I would also want to check the camshaft timing.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Last edit: 8 years 11 months ago by Andy.MacFadyen.
Hey Andy thank you for your quick reply, yes I did hone the cylinders I checked the timing and it looks good I will post some pics later to see what you all think. What about my question of the rings should the thicker ring go first?
Hey Gilbert! No chance of an intake restriction, causing low compression? Maybe throw a vacuum gauge on the intake during cranking, just to be sure.
Tried a leak down test yet? Just to confirm that the pressure is going into the crankcase. Or not, depending on what you may find.
As for the piston rings, I think that'd be a manufacturer specific thing. I'd have to look on Mitchell and see what it has to say about the piston rings.
I was thinking this morning on the same lines as Tyler I never asked if the test were done with the throttle wide open. The numbers fit the test being done without openning the throttle. For a valid test the throttle has to be held wide open.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Last edit: 8 years 11 months ago by Andy.MacFadyen.
This is the deal with this car i cranked the engine over to built oil pressure and heard a low cylinder and got stuck on that. I was ready to take apart the engine the next day but something said stop clear your head . i worked on another car then went back to the car i plugged in the fuel pump and started the car ran a little rough then settled in. I think the pistons just needed to sit right how dumb i'm i. This is the second time i install rings and bearings i'm new at this sorry for the falls call and thank you very much for your help.
gilbert wrote: GOD bless you my brothers and sisters.
This is the deal with this car i cranked the engine over to built oil pressure and heard a low cylinder and got stuck on that. I was ready to take apart the engine the next day but something said stop clear your head . i worked on another car then went back to the car i plugged in the fuel pump and started the car ran a little rough then settled in. I think the pistons just needed to sit right how dumb i'm i. This is the second time i install rings and bearings i'm new at this sorry for the falls call and thank you very much for your help.
Not dumb at all! Honestly, I haven't torn down a lower end since college. I think it's awesome you're willing to do this kind of rebuilding
Thinking about it now, I've had a couple reman engines from Jasper and the like do this kind of thing. On the first crank, you'd swear they didn't put it together right, but it all works out.
Tyler my brother thank you and all of the Danner family for the support you all give. This forum had been a real blessing to a lot of us thank you again.
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