Valve stem seals on engine. Need help.

[alacran]

96 3100

Ok, i got the front head off and i changed all of the velve stem seals. It was not easy but its done and half of the old ones were passing oil. Before i install the head i want to change the seals on the rear bank.

Any suggestions? I know the piston should be TDC but if #5 is at TDC what cylinder (2,4,6) will be at TDC?

I am thinking if #1 is at TDC then #6 is also at TDC. #5 and #2 should be at TDC and then #3 and #4. Is this wrong? Should I just reference the cam? Also, i thought about looking through the intake runners with the intake valve springs out but i am afraid of dropping one.

Last question. Do i need to remove the sparkplug and use a screwdriver or something to hold the valve shut?

I am just looking for the best method sorry for all of the dumb questions.

TIA

[alacran]

nevermind i pulled the plugs and figured it out.
#2 - #3
#4 - #5
#6 - #1
are at TDC.

No compressed air needed. I did find a problem with the valve stem seals. The guides are too far up on three valves. Shrug.

Correction:
#1 - #4
#2 - #5
#3 - #6
Are TDC together.

[SappySE107]

no. 1 and 4, 3 and 6, 2 and 5. follow the coil packs waste spark setup. They fire both pistons at the same.

Your guides came loose? Time to replace that head.

[alacran]

I think we are both right. I have pictures to confirm my stuff. I will see if my dad wants to replace the heads. Its up to him. At this point i could care less.
EDIT: I actually do care now b/c i dont want to do all this work for nothing.

[SappySE107]

Well its impossible for us to both be right. I want to see pictures of the valve guide.

[3400-95-Modified]

If there is a will there is a way... lol remember 60* motors are not interference motors according to some highly trained ASE certified GM mechanics...

LOL

But yes as Ben said, the numbers shared on the coil packs are the opposing cylinders since one would be on exhaust and the other would be on compression stroke, the way the waste spark works.

[alacran]

Well its impossible for us to both be right. I want to see pictures of the valve guide.

I will try to post pictures tonight. I took a picture of valve stem seal installed over the valve guide. I did not take a picture of the valve guide itself because to the naked eye it looks fine. The guides are not loose.

I put the engine at #5 TDC to work on #2 but the valve traveled too much so i pulled the spark plug and verified #2 was not at TDC. I continued to rotate the engine clockwise to get #2 at TDC and when it got there #3 was at TDC. Explain that.

I called around and everyone at the machine shop says the gudes moved up because of an overheat and that i need a valve job. $250 for the pair.

I told my dad about it this morning and he says to put it back together but we will talk about it later. Basically, the engine was running fine before and that he if gets 2-3 years out of the car than its a done deal. We will see what happens i will check the valve closely next time. The goal is to get it to stop throwing the P0401 code and we are done.

Any thoughts? Obviously i want to fix it right but ultimately its up to him if he wants it fixed.

TIA

[3400-95-Modified]

I can't explain what happened with you, but here is picture proof, 1 and 4...


And a P0401 is a Exhaust Gas Recirculation Flow Insufficient Detected... why are you doing valve seals?

[alacran]

I can't explain what happened with you, but here is picture proof, 1 and 4...


And a P0401 is a Exhaust Gas Recirculation Flow Insufficient Detected... why are you doing valve seals?

Ah, i had it backwards...#1 is right front not left front of the engine. That was confusing but it is cleared up now. I am not familiar with 3100 engine, i apologize.

P0401 sets when it fails the OBD EGR test. The O2 has some ash on it but not gunked up. The original goal was fix the engine leaks (LIM gasket) and replace the O2 sensor to get it going. Thats when i found two valve stem seals out of place (moved up on the valve stem) so we got new valve stem seals and on replacement found three valve guides moved up and other seals looked ok but passing oil too.

Does that clear it up? Any thoughts on the valve guide deal. They are tight but i wonder how long they will last.

[3400-95-Modified]

Rule of thumb for any GM engine, the furthest forward cylinder is #1, in our case that would be the back cylinder on the passenger side for a FWD V6, a V8 it's on the opposite side.

[alacran]

Here are the pictures...

New...


...installed on bad valve guide


Any thoughts or opinions will be appreciated.

[3400-95-Modified]

We need to see pictures of the valve guides themselves with no seals on them in comparison to others that aren't bad.

[alacran]

What difference does it make or why?

[3400-95-Modified]

because we can see how further up the valve guide actually is... the guide itself is not visible in that pic... your best bet is to measure the height of the guide with the seal off so you can figure out how much higher they went.

[alacran]

i would say the worse one moved up 1/8" (the base will not fully seat w/o the spring on it.)and the other about half that. The one pistured is one of the better ones that moved up. The black base is all the way down and the seal is being pushed up a small fraction. Keep in mind its not losing coolant, fouling the spark plug, or overheating. Although i bet it was overheated before.

It almost looks like the guids were installed that way but i doubt it.