Good evening, I posted earlier that I thought I may have a spun bearing:

https://www.fiero.nl/forum/Forum2/HTML/119273.html

We replaced the bearings and they hadn't spun, but were worn quite a bit. After doing so, the ticking did not go away, and we think it may be a sticking/collapsed lifter b the sound and the symptoms which include:

* Ticking from the top rear driver side of engine that gets louder with RPMs, drops/stops momentarily when let off.

* missing at higher rpms (at around 35mph)

* Only reading 10-ish PSI at Idle (read with a mechanical gauge, I don't trust the one in the car quite yet.)

What we have done thus far:

* Dropped oil pan, replaced worn connecting rod bearings, cleaned oil pan out.

* Changed oil, oil filter.

* replaced a cracked catalytic

* Replaced EGR Tube to fix high idle (Idle when we start is still like, 2000 rpm, drops to about 1300 when driving around, is that still high?)

* Replaced the MAP, IAC, Oil sending unit.


So, thoughts?

You need more oil pressure. What engine?

2.8L V6.

My suspicion is that the low oil pressure might be due to the lifter being collapsed?

No a lifter will not cause low oil pressure. Main bearings will dump more oil pressure than the rods will, they are where the oil enters the crank to get to the rods. I would try putting in new mains, it is easy to do with the engine in the car, you just put a cut off nail or something like that in the oil hole and rotate the crank to take out and put in the top shell. If not that then you can also put in a new pump while it is apart. 10 psi at idle isn't really that low. The ticking noise could be piston slap, very common for this engine, and the miss unrelated. Larry

you probably have a lifter that is wearing down a lobe .in a 2.8 the lifter galleries are primary oil supply .that means the oil goes through there before it gets to the main bearings .so when a lifter wears down it bleeds off pressure .i had this happen and the miss was one of the giveaways as well as erratic oil pressure .

quote Originally posted by trotterlg: The ticking noise could be piston slap, very common for this engine, and the miss unrelated. Larry

If it was piston slap, wouldn't it get quieter or stop altogether when the pistons warmed up and expanded to fill? because that isn't the case, it is fairly constant, but slightly quieter on startup (at least if it is the first startup of the day.)

[This message has been edited by P-Dub (edited 10-15-2011).]

Yes, unlikely to be piston slap if it doesn't go away when it gets hot. Could be a wrist pin, they make a fairly light tap that generally gets worse as it heats up. You would need to grind a lot of lifter away to dump oil out the bottom of the lifter bore, but I guess it could happen. You would find one very loose rocker arm if a lifter was that bad. Larry

i would take the valve covers off before i would go tearing in to the bottom end .older pushrod motors always have ticking lifters any ways .what is the oil pressure when you are all warmed up and at a steady 60 mph?that is what you need to worry about more than idle oil pressure .you might be worried about nothing .

10 psi at idle meets GM's minimum spec for that engine, though more is almost always better.

WRT the ticking: If the tick varies with RPM only then it's likely valvetrain because loading in the valvetrain bits does not change with power output, only RPM. If the ticking changes with throttle then the problem's in the rotating assembly, the crank, rods, or pistons as these parts are subject to loading changes from varying power outputs.

Note: Since this engine gets its bottom end oiling via the cam bearings, if your cam bearings are worn excessively then oiling to the rods and mains will be compromised even though the gauge shows sufficient oil pressure. The oil pressure port on the engine block only measures the oil pressure between the oil filter and the camshaft bearings, not after that point.

Found the issues: collapsed lifter and bent pushrod.

Full album of it here:
http://imgur.com/a/txTpx

LOVE the image titles. Made me laugh pretty good. Kinda like a frustrated storyline.

Oh, and congrats on the fix, hope that does it.

I hope it works. Let me ask this forum: the valve lash procedure, is it supposed to be that vague? What they defined as drag was rather subjective person to person, and one manual had us tightening 1-1/2 turns (chilton) after drag is felt while the other had us doing 3/4 turn (haynes) after drag is felt.

Whatever "drag is felt" is supposed to mean. Are the pushrods supposed to be tight like that? I can't remember what they felt like before we took them out, but I can't really trust that bunch of banana sticks.

quote Originally posted by P-Dub: I hope it works. Let me ask this forum: the valve lash procedure, is it supposed to be that vague? What they defined as drag was rather subjective person to person, and one manual had us tightening 1-1/2 turns (chilton) after drag is felt while the other had us doing 3/4 turn (haynes) after drag is felt. Whatever "drag is felt" is supposed to mean. Are the pushrods supposed to be tight like that? I can't remember what they felt like before we took them out, but I can't really trust that bunch of banana sticks.

I remember when we rebuilt my 2.8 that we had a serious problem when we OVER torqued them. A buddy of mine torqued them down so hard that the valves wouldn't close and we had no compression, which was causing the engine to not start. After he realized his mistake the correct torque was applied and it started and ran beautifully. Now unfortunately I have no clue what the torque ended up being, as he was the one who did all that. I do remember looking very thoroughly through 2 different manuals with no clear indication of the correct setting.

Maybe settle in the middle and do 1 good turn?

https://www.fiero.nl/forum/A...100421-2-095970.html

here's a thread about it. Enjoy.

quote Originally posted by TheRealShadowX: I remember when we rebuilt my 2.8 that we had a serious problem when we OVER torqued them. A buddy of mine torqued them down so hard that the valves wouldn't close and we had no compression, which was causing the engine to not start. After he realized his mistake the correct torque was applied and it started and ran beautifully. Now unfortunately I have no clue what the torque ended up being, as he was the one who did all that. I do remember looking very thoroughly through 2 different manuals with no clear indication of the correct setting. Maybe settle in the middle and do 1 good turn?

We noticed when piston one is Top Dead Center that one of the 12 pushrods (one on cylinder 3) was a bit looser, turn it over to piston 4 TDC and a different one was looser (one on cylinder 6), which kind of seems to be right. When we cranked it over by hand, it *appeared* that all the valves opened and closed correctly.

But seriously, the valve lash procedure in this engine is goofy.

[This message has been edited by P-Dub (edited 10-17-2011).]

quote Originally posted by P-Dub: But seriously, the valve lash procedure in this engine is goofy.

Yup, I have yet to do them myself but there’s lots of threads about doing it. Here’s another one I found with the search “valve lash”
https://www.fiero.nl/forum/A...110502-2-102549.html