Head Gasket/LIM & Up (HELP)

[SlamedAM]

I just recently replaced all the gaskets on my car from the heads up. (95 3100SE)

I've called three mechanics, all of which say the valves are NOT adjustible on this particular engine, however my dad says they are.

My dad says he adjusted them and now the engine runs a little smoother at idle.

When I drive it, it only runs smooth in high RPMS or on flat ground.

As soon as I put stress on it (hit an incline), I have to shift down to third gear (automatic tranny) to keep it smooth, if not, it starts sputtering like a coil pack or something..

But at high RPMs it runs like it did before I took everything apart.

Any suggestions here?

[rixGAphx]

Your valve lash is NOT adjustable.

You have hydraulic valve lifters, which automaticly 'adjust' the lash.
Only mechanical (solid) lifters are adjustable (ignoring wierd and sophisticated engines).

BUT, you have a major re-assembly problem, and you need to STOP running this engine, NOW, before you do (any more) serious damage.

The proper procedure for removing heads from a pushrod OHV engine is to remove the stress from the rocker arms before loosening the headbolts.

On many engines, the rocker arms are all lined-up, mounted to a single shaft. To remove the stress, loosen the bolts that hold the shaft to the head, and lift the whole thing off.

On our V-6's, the valves are 'canted', so the rockers can't be lined-up on a single axis.
Instead, each rocker is screwed-in to the head at a slight angle with a special stud.
To remove the stress, loosen EACH of the 6 rocker arm mounting nuts, and rotate each rocker arm aside (don't remove it)
* * *
Then, remove the pushrods, and keep them in order:
* Reason 1: They have been paired with their respective lifter and rocker for a bazzillion revolutions.
* Reason 2: The exhausts are different lengths than the intakes (on our goofy V-6') :eek: .

Finally, you're ready to R&R the heads and gaskets.

Re-assemble:
* Torque heads in place.
* Insert pushrods into respective locations.
* Rotate rocker arms over pushrods, and TIGHTEN THE NUTS!!!!!!!
This is what your dad was doing: not 'adjusting' the valves, but seating the rocker arms the way they should have been seated initially.

I fear your dad hasn't gotten to a few of the nuts.

More likely, you have some short pushrods where longs should be, and the rockerarm nuts can NEVER be tightened enough to compensate (the difference in length is only about 3/16" IIRC, but that's a BUNCH when you have valve lift of 1/4" and a rocker ratio of 1.6:1)

So: Remove the valve covers, loosen all the rocker arms, remove all the pushrods.
Determine which are intake and which are exhaust.
Replace rods which are not perfectly straight (one of the long ones, in a short position, might have been bent).
Install pushrods in proper positions, and tighten the rocker arm retaining nuts to specified torque.
[Since you no longer know which pushrod was originally with which valve and lifter, you have three choices:
* Ignore the situation (this is a perfectly OK choice).
* Replace all the pushrods.
* With very fine emery cloth, put a slight polish on the existing pushrod ends, then give them a good solvent cleaning; the polishing will tend to 'even-out' the differences between the rod ends and the lifter/rocker faces.

Good luck.
-Rick

[Colin]

Originally posted by SlamedAM
I've called three mechanics, all of which say the valves are NOT adjustible on this particular engine Including Rick and Myself , now five mechanics . ;)

[mikem220153]

Let's make that 6. No the Rockers ARE NOT adjustable. And as Rick pointed out, you could very well have intake and exhaust push rods mixed up. Don't drive the car until you have this straightened out. Worst case scenario is having pistons banging into valves and that equals a new motor.

[HeyDace]

Make that 7. But... If the pushrods are swapped (intake for exhaust) you will have a noticeable skip at idle and it would back fire off idle.
What promted the upper engine overhaul to begin with? Lack of power under load may be caused from fuel delivery, ignition, restricted exhaust, EGR or timing to name a few. Did you send the heads out to get checked? A cracked valve or a weak spring(s) are other possibilitys.

[99GrandAMSE]

... I like having access to all these mechanics :)