Rb25 no compression in any cylinders

**nardocrew** · 08-04-2010, 02:01 AM

I just recently did a rb25 swap into my r32, I cannot get the car to start, turns out there's no compression in any of the cylinders, there's spark, fuel and the engine spins, I purchased the motor from a reliable seller who says they tested the compression and replaced the timing belt and all was good.
I didn't mess around with the timing or remove the cams so I don't believe there is any possible way I could have bent the valves, let alone all of them. the only thing I did mess around with while trying to get it started is the cas, is it possible that's the cause of no compression? and if not does anyone have an idea what else could be causing the problem? I have yet to pull the head off to check the valves.... Also its a series 2 rb25 and it has hydraulic valves

Any help would be greatly appreciated

Thanks

**nardocrew** · 08-09-2010, 06:07 PM

I tried it throttle open and closed, i have yet to pull the head off but I pulled the valve covers off and the exhaust valves are all stuck open slightly and all the intake valves are closed and in perfect condition, all the valves move, cams spin and its all timed correctly. Is it a common thing for an engine thats been sitting for 6 months or w.e it is to have valves stick for any possible reason, I want to leave pulling the head as my last resort assuming the exhaust valves are bent...

Thanks alot for your help

**BrianV8** · 08-09-2010, 11:35 PM

i would double check the timing on the cams, could be out

**Brendan** · 08-10-2010, 03:05 AM

My money is on the exhaust valves being bent. They don't really get stuck open for any other reason.

**Derek** · 08-11-2010, 12:29 AM

This happened to me when the timing belt on a 4ag skipped three teeth after being installed correctly.
You say the timing is correct however.

The sound of zero compression still rings in my memory.

How about pictures of the exhaust valves stuck open. I really can't see why all of them would be left open.

Hmmm. The series two engine has a variable cam timing system... Just thinking...

Pics?

**Brendan** · 08-11-2010, 12:57 AM

It's only the intake cam that's variable so that wouldn't really apply to this situation.

**nardocrew** · 08-12-2010, 01:27 AM

Ill definitely take some pictures tomorrow after work and throw them up, Im going to try a new technique tomorrow to push the valves up and see if it does anything at all, if not im just going to resort to pulling the head off...

Thanks a lot I might even take a video of the cams and valves when its turning over and throw it on youtube so you can see whats going on

**nardocrew** · 08-13-2010, 11:08 PM

Intake cam valves fully closed.

Exhaust cam valves stuck open slightly.

And a couple videos of cams and valves while turning the car over...

Intake cam

Exhaust cam

**Rblove26** · 09-07-2010, 06:54 PM

Another easy and good way to tell just about exactly whats going on in the cylinders is to just do a cylinder leakage test. you gotta check each cylinder one at a time by just bringing them up to TDC (so both valves are closed) and applying shop air. you'll need an adapter that threads into the spark plug hole and fits on the end of a air line. if you are loosing compression you'll find it by just listening

air coming out intake = bent intake valve
air out exhast = bent exhaust valve
also could be timing...but you'll just have to double check it
pull the dipstick and oil cap to check = means the rings arent any good (or pistons etc)

anyway if there is a leak you can find it this way and at least give the source
good luck

**1991HCR32** · 09-10-2010, 06:44 PM

This exact same thing happend to me. I bought a rb25 swap and motor was garbage when it arrived(lets not name the engine supplierlol)
so I sent it back and demaned a refund. How many kms did they say were on this motor? the usual 25-60 thousand ??? lol lies