Timing belt is on, timing mark are lined up, yet failing leak down test on all cylinders. Have air leaking at throttle and exhaust as crank pulley is rotated. Is there anything I might be forgetting to check before I pull the heads.This is a Copart engine and has broken timing chain cover,

Edited February 6, 20188 yr by steve56

Make sure test equipment is working properly,how does compression test look?

No compression test engine out of car.

Edited February 6, 20188 yr by steve56

When you crank it over is tensioner jumping around or holding steady?

It was oviusly in front end collision,what does copart have to say about this?

Did this have a snapped timing belt? If so it sounds like bent valves to me. That means swap engine for known good one or pull heads, inspect damage and go from there. At the very least this would mean a full overhaul of the heads.

 

 

Cheers

 

Bennie

Very good other pp that's what I was trying to say.

Did this have a snapped timing belt? If so it sounds like bent valves to me. That means swap engine for known good one or pull heads, inspect damage and go from there. At the very least this would mean a full overhaul of the heads.

 

 

Cheers

 

Bennie

The only thing that makes sense to me is, the timing belt snapped and someone put it back on.

How broken is it? Front end wreck? If the belt is intact you need to look at the ARROWS that indicate TDC for leak down testing. Arrows on cam sprockets should point at 12, 3, 6, and 9 o'clock (following firing order) to set valves at TDC closed positions.

 

Using timing hash marks will give you open valves on some cylinders.

The only thing that makes sense to me is, the timing belt snapped and someone put it back on.

How dodgy is the seller? Are they known for this sort of thing, or is it possible the PO had the crash, straightened out the front end, replaced the cam belt and found it a non runner so moved it on, only to have you buy a bung engine?

 

It’s difficult to know this information but it seems feasible to me. Any chance of a replacement or refund on the engine?

 

And how badly cracked were the cam covers? All it takes is a piece of metal in there to shred the cam belt. I had a stick almost do it to my ej22 while out 4wdn...

 

Cheers

 

Bennie

How broken is it? Front end wreck? If the belt is intact you need to look at the ARROWS that indicate TDC for leak down testing. Arrows on cam sprockets should point at 12, 3, 6, and 9 o'clock (following firing order) to set valves at TDC closed positions.

 

Using timing hash marks will give you open valves on some cylinders.

 

How broken is it? Front end wreck? If the belt is intact you need to look at the ARROWS that indicate TDC for leak down testing. Arrows on cam sprockets should point at 12, 3, 6, and 9 o'clock (following firing order) to set valves at TDC closed positions.

 

Using timing hash marks will give you open valves on some cylinders.

Hi Fairtax.It was hit in the front.The belt and all belt idler pulleys are intact.,There was a broken drivers side outer tbelt cover and the drivers sides cam pulley is worn on one side, I can do a complete crank shaft rotation with the leak down tester in any cylinder and there is 80% leakage at throttle body and exhaust ports on all cylinders.

wh are you rotating during hte leakdown?

 

set the cam to where the cyl you want to test is closed.  Hold the crank from turning, fill the cyl with compressed air.

 

FWIW, these aren't aircraft engines.  They won't hold 100% ever.  If it's mostly holding and not just wooshing straight out it's probably fine.

Hello? McFly? Check the valve lash. 

 

GD

wh are you rotating during hte leakdown?

 

set the cam to where the cyl you want to test is closed.  Hold the crank from turning, fill the cyl with compressed air.

 

FWIW, these aren't aircraft engines.  They won't hold 100% ever.  If it's mostly holding and not just wooshing straight out it's probably fine.

Thought turning the crank 720 degrees with the leak down tester set at 100psi in any spark plug hole,I should get tdc and accurate leak down percent..

Thought turning the crank 720 degrees with the leak down tester set at 100psi in any spark plug hole,I should get tdc and accurate leak down percent..

turn the crank 720 degrees and you will have opened both intake and exhaust valves on all cyls, lol.

 

You don't rotate during leakdown.  You set one cylinder to a point where all valves closed, and then fill cylinder and see how long it takes to "leakdown".  Read result.

 

Then rotate 180 to the next cyl, then repeat.  

 

Don't rotate the crank during the test or you throw it all off.

 

you could pull the T-belt off and set all valves closed (Pass hash up, Drivers hash down)  then you could rotate all day....still will throw off readings as you will be compressing and "decompressing" the air each time the piston goes up and down in the bore.

Hello? McFly? Check the valve lash. 

 

GD

 

Hello? McFly? Check the valve lash. 

 

GD

Just rechecked cylinder one at the 12 cam arrow position and cylinder three at the 3 cam arrow position and both have .010 valve lash..

Just rechecked cylinder one at the 12 cam arrow position and cylinder three at the 3 cam arrow position and both have .010 valve lash..

 

.010 Valve lash is too loose.  assuming you mean inches.

 

The subaru spec is .15 MM  not .010 inches.

 

which would be only .006"

 

not yer leakdown issue but not correct either.

.010 Valve lash is too loose.  assuming you mean inches.

 

The subaru spec is .15 MM  not .010 inches.

 

which would be only .006"

 

not yer leakdown issue but not correct either.

II'm using .080 inch gauge for intake and .010 inch gauge for exhaust.

Should be about .006" for intake, and about .008" for exhaust. Otherwise they make noise. 

 

If the engine has been sitting then it's fairly typical for them to have low compression from the rings being dry. Squirt some oil in the cylinders and crank it a bunch. 

 

GD

Should be about .006" for intake, and about .008" for exhaust. Otherwise they make noise. 

 

If the engine has been sitting then it's fairly typical for them to have low compression from the rings being dry. Squirt some oil in the cylinders and crank it a bunch. 

 

GD

Thanks GD  You always have great advise.

Just pulled the drivers side head.Don't see any contact between valves and pistons. The water pump bearing is bad and hardly turns. Dont see how that would have anything to do with bad leakdown results though.Head gasket looks fine.

If you're pulling the heads anyway - it would be silly to not install some new rings. They are cheap. Don't hone it - just ring slap it and drop the heads back on. 

 

GD

If you're pulling the heads anyway - it would be silly to not install some new rings. They are cheap. Don't hone it - just ring slap it and drop the heads back on. 

 

GD

Yes , But I was getting 80% leak down on all four cylinder exhaust ports. Where would that come from.. Exhaust valves didn't make contact with pistons. and dont look bent, Very confusing to me.

he simply means replace rings if youve gone this far anyway.

 

bent valves. Pressure test the heads or fill exhaust/intake ports with something noncorrosive and watch the leaks.

 

Bent valves doesn’t sound surprising given accident impact, broken belt covers, damaged camshaft sprocket, damaged water pump...and all of those being on the same side with bent valve symptoms.

 

Jumped timing from impact?

Maybe they’re bent enough to leak but not show visually.

 

I haven't seen many but seems to me these usually bend most, or all, the valves.

Edited February 7, 20188 yr by idosubaru