Hello, I recently did an engine swap on my manual '06 tC. I swapped my stock engine with, well, another '06 tC engine (automatic). This was to act as a 'safe' engine for further modification so that I could always revert back to stock. I did plenty to the engine and transmission*, including larger, lighter pistons, new connecting rods, and a dual clutch w/ flywheel. To accommodate all this, I had the engine taken to a machine shop where the cylinders were bored out for the pistons and the header was leveled, along with ported and flowed intake and exhaust holes.

After reassembly, the engine would not start. It would turn over, the pistons would move, the camshafts would rotate, but it would not start up. I rechecked the timing -- and it was off, it had been aligned to the wrong marks, so this was fixed. However, the engine still would not start.

I have checked spark plugs, and they work.
I have checked fuel injectors, and they work.
I have checked compression, and there is none. Zero. In all cylinders.

I now how no clue what could possibly be wrong anymore. If anyone could help, it would be very much appreciated.

*Not sure if this is relevant, but... Differential was replaced with a LSD and the exhaust was replaced with a turbo-back exhaust system (no turbo, yet). I also have an old CAI from pre-swap.

 

if its showing 0 compression either your compression tool is broken or there is no pistons in the motor, because even with no rings it should still show something

 

Tested the compression tester with a bike pump. It works.

Also, there are definitely pistons in there.

 

bent valves when timing was wrong, and now they are all open? open valves would prevent compression as well.

 

Check your cam timing and make sure theyre properly degreed, even if youve done it once, do it again (ive made the exact same mistake before on a different motor and swore i had degreed them right the second time), if for some reason theyre off by around say 90* then you could be in compression strokes when at least on of the cams is "open" in which case you will see no effective compression. If for some reason you built a motor with interference pistons, then bent valves could also be an issue. either that or it may be possible (but HIGHLY unlikely) that you have multiple stuck valves from an improper build.

Best of luck,
TYLER

 

Oo man! that realy suck to hear. Bro. you more likely have bent your valve when the timing was set wronge... do a leak down on the motor that will answer all your question. the next step is pull the head off and hope that the pistons are ok.

 

yeah pull that head and all of your questions will be answered

 

Thanks. I really hope the valves are ok though. I can't see the valves getting bent so badly through off timing that it would cause zero compression. I'll probably recheck the timing first before pulling the head.

 

Checked the valves on the exhaust side (side w/ bad timing on camshaft). A couple are very very slightly bent, and the rest are fine. I'll check the intake side later, but it doesn't seem like the valves are the problem, as they wouldn't explain zero compression in all pistons. Also, I tried a little bit of motor oil to create a seal to check for bad rings. It did nothing.