No compression. Help me supra gurro!!

[Semper_Fi]

Ill make the description short annd sweet.
No compression in engine.
head went to the shop.
New piston rings.
The cylindars were honed...
The gap in the piston ring is .030 inch, which is in range by the book.
New headgasket.
What am i missing?

[El Supracabras]

Post up the actual test numbers for each cylinder. No way they all have no compression. Otherwise a shot in the dark guess would be you somehow installed the cams with a valve open on every compression stroke. Not sure if it's even possible.

[87hilux7mge]

my guess would be improper cam timing. the valves are probably open during compression strokes.

did you make sure to use a proper compression tester? those "hold in" ones arent worth a damn. a screw in type with o-ring gaskets works great and are only about 15-20 bux.

another option is improper tq specs on the head bolts, left a gap somewhere maybe?

[Semper_Fi]

Originally Posted by 87hilux7mge

my guess would be improper cam timing. the valves are probably open during compression strokes.

did you make sure to use a proper compression tester? those "hold in" ones arent worth a damn. a screw in type with o-ring gaskets works great and are only about 15-20 bux.

another option is improper tq specs on the head bolts, left a gap somewhere maybe?

Yeah i checked it with a renter from autozone... i believe the last three were getting some kind of compression, but after checking the first 2. i jumped to the conclusion that i installed the piston rings wrong. So i ripped it apart.. were do i start?? thanks for the support everyone.
Thanks again. Carlos

[87hilux7mge]

check ring gaps if you took the pistons back out, and also make sure they are all indexed properly, cuz if you have all the gaps in the same spot, they will not seal as well. u can find the proper index chart in a repair manual or the cygnus TSRM.

then just carefully reassemble everything. id make sure your head/block surfaces are very clean, then when you put the gasket back in, spray it down with some copper spray, or if your using a MHG, put a thin coating of gaskecinch on it (they both improve the seal of the gasket).

double check all your valve seats and valves themselves, to insure they arent bent. you could have your head vacuum tested to see if you have any leaks (usually pretty cheap or free at a engine shop).

then just double check your install of the timing belt to insure proper valve timing. also, make sure to coat the cylinder walls with a thin layer of clean motor oil, and putting a tiny bit in the upper cylinders helps with compression tests.

then try your test again, hopefully you get better readings this time, GL!

[Semper_Fi]

thanks everyone again for the help. The last 2 post, got me researching like there is no tomorow. Thank you all.


but i guess i can set my fate as a noobie with this one question... My block Just sais 7m... is it soposed to say 7mgte? the timing cover sais 7mgte, but that can probably be changed to say whatever on it.

thanks. Carlos

[87hilux7mge]

all the 7m blocks were stamped 7m. they didnt differentiate between the ge and gte. as far as i know...

[cre]

Even if the rings aren't properly indexed you should still get decent compression across the board (probably close to the minimum allowed).... A wet test should pass fine though. My money's on valve timing.

[87hilux7mge]

yea i just wanted to cover all his bases, my money is on the valve timing too.

[Semper_Fi]

Yeah im guessing the head was poorly done. were taking it to get vaccuum tested monday morning, and were gonna attempt to put her back together. Is there any way to tell if the head is warped???