[russ98stang1]

OK, I rented the tool form Oreily's yesterday, it was brand new still in the wrapper. But anyway, i just got done and got some disturbing results. This is the pressure/cylinder.
Passenger side Driver side
4 150psi 8 180psi
3 145psi 7 180psi
2 150psi 6 185psi
1 150psi 5 140psi

Ok, I just had the pi swap accomplished (well i dont know about accomplished) about 3000 miles ago or 4 months ago. So the heads had been reworked and were like brand new, as far as the valves and valve stuff goes, the cams, springs, cam followers, and lash adjusters are the existing ones. So im hoping its not a gasket issue, but #5 is worring me a little. Now on the passenger bank, its screwing with my head. Im beginning to think my original prediction is coming true wich is that the cam timing is off 1 tooth.
I really need some help on this because im going to have to take this ****er to court if its somthing like cam timing. Please help with any input that you guys may know or experieced.

Another question, could a collapsed lash adjuster cause compression loss?

Ps: heres a video of the tapping sound my engine has been making, Some mechanics that i stopped by and talked to said its definetly in the top end, but who knows.

This is at cold start when engine idles high.

[Outcold]

squirt oil in the cylinder that is low and see if your compression raises. if it does then that means you have bad rings. theres a start also if your timing chain is off just one tooth you can more than likely compensate that with the turn of your distributor.

[Outcold]

is it a high pitched noise or is it a low pitch sound. also you could take off your valve covers run the car and see if you feel any kind of vibration or something out of the ordinary buy pushing your hand on the lifter

[russ98stang1]

Distributor????

[racin366]

I'm assuming the tapping wan't there before the swap. It sounds like a valvetrain issue, could be a lot of things. I think if the cam were off a tooth it wouldn't be a problem with only 1 cylinder. It could be an oiling problem, lash adjuster, or problem with the head. What weight oil are you using, and if you did the PI head swap why did you use the non-PI cams, a lot of the power gained with the swap is in the PI cams. If the heads are good I would think its a problem with the rings, but the ticking sounds like a bearing or cam issue.

[wantsum5.0]

sounds like lifter noise to me.that or one of your rockers needs tightening.

[duckbubbles]

The distributor will not have any affect on cylinder compression.

A collapsed lifter can make the results lower by not opening the valve as it should. You might try a leakdown test. Pressure is applied to the cylinder while it is on top center of the compression stroke. A pair of gauges indicates the applied pressure and the retained pressure. You want to see 90% plus on the retained pressure.

By listening at the exhaust, if you hear air escaping it is an exhaust valve leaking. By listening at the intake, it may be an intake valve leaking. Air escaping from the crankcase breather means the rings are leaking. This test is done with the engine not rotating.

Frank

[racin366]

The 98 is an overhead cam engine, there are no rockers.

[2oo5GT]

Originally Posted by Outcold

squirt oil in the cylinder that is low and see if your compression raises. if it does then that means you have bad rings. theres a start also if your timing chain is off just one tooth you can more than likely compensate that with the turn of your distributor.

Lol, there is no distributor on the 4.6 mod motor. cool.

[2oo5GT]

Sounds like a valve issue to me.

[russ98stang1]

Originally Posted by racin366

I'm assuming the tapping wan't there before the swap. It sounds like a valvetrain issue, could be a lot of things. I think if the cam were off a tooth it wouldn't be a problem with only 1 cylinder. It could be an oiling problem, lash adjuster, or problem with the head. What weight oil are you using, and if you did the PI head swap why did you use the non-PI cams, a lot of the power gained with the swap is in the PI cams. If the heads are good I would think its a problem with the rings, but the ticking sounds like a bearing or cam issue.

I dindnt use non pi cams, i reused the stuff that came on the pi heads. sorry for the confusion. also, what i was talking about when i said the timing issue is that the whole passenger head has 30 pounds less pressure.

[russ98stang1]

I just now remembered somthing, i dindnt have the throttle open when i did the test, will that have an effect on anything? I know it isnt going to change the difference in pressure from one cylinder to another though.

[racin366]

Originally Posted by russ98stang1

I just now remembered somthing, i dindnt have the throttle open when i did the test, will that have an effect on anything? I know it isnt going to change the difference in pressure from one cylinder to another though.

The throttle will have a large effect on the numbers you get, but not the 30lb differential you're getting. I would bet the cam is off a tooth, most other problems wouldn't effect the whole bank of cylinders. Be careful, if its off enough the valves could hit the pistons, that could be what you're hearing. Just in case, try checking the compression again with the throttle wide open. You can also pull the valve cover and see if the cam looks ok, but checking lobes o while the cam is in the car is hard unless there is a huge problem like a lobe being wiped off. I don't want to be a negative nancy, but you may have more than one problem.

[BlueStreak03]

Originally Posted by Outcold

squirt oil in the cylinder that is low and see if your compression raises. if it does then that means you have bad rings. theres a start also if your timing chain is off just one tooth you can more than likely compensate that with the turn of your distributor.

There is no distributor on that car.

Cam timing being off would show issues with multiple cylinders on the same side.

As was suggested, quirt some oil in ALL the cylinders and do the test again and see if you have the same TREND. The numbers will be higher all around. You're looking for a trend. If the trend for #3 and #5 stays, then it's a ring problem. If it goes away, then it's a valvetrain issue.

[russ98stang1]

Quoate "Cam timing being off would show issues with multiple cylinders on the same side."
Check out the entire passenger bank compared to the drivers. about a constant 30psi difference with an exception to #5.