i screwed up. are my valves bent
#1
i screwed up. are my valves bent
posted a thread earlier on how to find tdc to adjust valves. what i should have told you first is my son and i were replacing head gaskets. he done most of the work i gave most of the advice. he should have gotten better advice. when he asked about tighteng rocker arms i automatically said newer engines are not adjustable,just tighten all the way. i guess a 94 3.4 isnt that new as they are adjustable. anyway with them all the way down the engine was completed and turned over w/ no compression. then i started checking chiltons for valve adjustment which we went back and redone correctly. now it doesnt start easily, doesnt run smooth, and backfires thru intake. does anyone know for definite there isnt enough room for clearance and the valves did hit. this will be very expensive head gaskets. signed doesnt need repair manual idiot
#2
Join Date: Nov 2007
Location: Eastern PA,
Posts: 10,351
I can not say if you motor is a interferance motor or not but as long as the timing chain is right I do not think you can crank down the valves so far that they hit the pistons. Most of the time when someone bends a valve it because the valve opened by the cam at the wrong time.
I know that is clear as mud. How about this, you can not open the valve with adjustment anywhere near as much as you can with the Cam.
I would think there is more chance of a bent push rod since the combination of your over adjustment and the cam exceeded the possible valve opening. I would remove the rockers check the push rods and check the height of the valves with a calipur or indicator. You might be able to just lay a straight edge across the valve to see if they are even. If they are all within a few thousands to each other they are most likely ok.
It could be that the over adjustment pushed all the oil out of the lifters so you did your first adjustments with bottomed out lifters. once the car was cranked they started to pump up and your valves hung open to far. You may get luckly and just re-adjust valves.
I know that is clear as mud. How about this, you can not open the valve with adjustment anywhere near as much as you can with the Cam.
I would think there is more chance of a bent push rod since the combination of your over adjustment and the cam exceeded the possible valve opening. I would remove the rockers check the push rods and check the height of the valves with a calipur or indicator. You might be able to just lay a straight edge across the valve to see if they are even. If they are all within a few thousands to each other they are most likely ok.
It could be that the over adjustment pushed all the oil out of the lifters so you did your first adjustments with bottomed out lifters. once the car was cranked they started to pump up and your valves hung open to far. You may get luckly and just re-adjust valves.
Last edited by Gorn; 12-07-2009 at 06:12 PM.
#3
thaks gorn. nothing bent but lifters need to pressurize
i got very lucky. still have the fuel injectors and air intake off so i can adjust valves. i am using compression tester after adjustments to make sure valves are closing. # 6 cyl giving problems. after setting 1 1/2 turns i have no compression. backing off to loose play i get 150# like all other cylinders. appears lifters arent pumping up. i actually loosened every one 1 turn off after loose play and turned engine a few revolutions w/starter and it appeared a few pumped up a little more. i will search here and a few more places on internet, but is there a good way to pump lifters back up while still in engine? thanks for helping me
#4
Join Date: Nov 2007
Location: Eastern PA,
Posts: 10,351
Loosen the valves and turn it over till you register pressure on the gage. I am not sure if anyone makes a primer for that car. Sounds like your on the right track.
Glad to help us Dads got stick together
Glad to help us Dads got stick together
#6
When setting for zero lash, I've found it works better to pull up and down on the pushrod while tightening the rocker nut. I would periodically have some that would spin fairly freely even though it had no lash. Because of that, I don't trust the "spin" method.
#7
thanks for your help. i was so close to lifters i went ahead and removed intake and cleaned all lifters and made sure they would compress and return. i went w/ chiltons 1 1/2 turn on rockers and other than a small exhaust leak my son is happy with his dad again. again thank you
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