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Fresh motor Valve train noise and glowing inlets to pre cats

Posted: May 23rd, 2018, 7:51 am
by Mousejockey
Just rebuilt a 4.0 and Im getting valve train noise ticking, loud ticking
New cam, lifters, pushrods, rockers, valve springs, 30w break in oil
Popped the valve cover and all is in place, rocker arm bolts are still at torque spec, a pool of oil in the little valley of each arm
I can not compress the lifters, there is no play in the rockers rocking them 'spring to valve' there is some movement 'side to side'
pushrods spin freely and have no up and down movement

Noise appears to be from the front of the train, with a stethoscope no one area seems louder than another front to rear

When running @ 2500rpm, in the garage, after a few min, the inlet pipes for the pre-cats start to glow, but not at idle



I rebuilt this motor cause I didn't like the V-train noise in the old one and it had a slight rod knock.
Now I still have the damn noise, and its louder than it was in the old motor

Any ideas?

Re: Fresh motor Valve train noise and glowing inlets to pre cats

Posted: May 23rd, 2018, 6:24 pm
by Mousejockey
Thinking the push rods may be to long, looking into checking measurements...

Re: Fresh motor Valve train noise and glowing inlets to pre cats

Posted: June 15th, 2018, 8:17 pm
by Mousejockey
Pushrods were to long, shimmed the rockers .090 and all is quiet

Re: Fresh motor Valve train noise and glowing inlets to pre cats

Posted: June 15th, 2018, 9:12 pm
by Mousejockey
Rebuilt a 4.0, .030 over
Started it up, ran like crap, clanking
reset the Cam synchronizer
started it up, ran smooth but alot of valve train noise - ran for 10 min @ 2500rpm - when running looked around for leaks and source of clanking - noticed pre-cat inlet piped glowing
shut it off - found pushrods were to long - shimmed rockers .090 restarted quieter but still some noise, ran for 10 min @ 2500 for cam break-in pre-cat inlets glowing
Found #3 intake lifter collapsed
replaced lifter motor quiet now, ran 2500rpm for 10 min pre cats glowing
drove it around the block awhile, no codes, no hesitation or backfires, runs good/strong
got scanner data trying to figure out the glowing pre-cats

MAP IDLE 1.6 2500RPM .9
VAC IDLE 17.7 2500RPM 22.1
F BANK INJ IDLE 4.6 2500RPM 3.8
R BANK INJ IDLE 4.5 2500RPM 3.8
F UPSTREAM IDLE .1~.8 2500RPM .1~.8
R UPSTREAM IDLE .1~.8 2500RPM .1~.8
F DOWNSTREAM IDLE .68~.72 2500RPM .3~.6
R DOWNSTREAM IDLE .68~.72 2500RPM .3~.6
F ST ADAP% IDLE .4~2.3 2500RPM -1.2~1.8
R ST ADAP% IDLE -.2~1 2500RPM -1.6~1.2
F LT ADAP IDLE 8.2 2500RPM 7
R LT ADAP IDLE 9.4 2500RPM 8.6
TEMP 199*

Disconnected the front 2 o2 sensors ~ ran at 2500rpm a few min
Pre-cats glow and got some engine codes
P0031
P0051
P0132
P0152

Changed the 4 o2 sensors on a whim
No change

Rechecked CPS hole alignment - dead on but noticed some play in the shaft
Swapped in a Dorman OPDA - no change

Plugs pulled after motor shut off @2500 rpm

1~3 top to bottom

Re: Fresh motor Valve train noise and glowing inlets to pre cats

Posted: June 15th, 2018, 9:14 pm
by Mousejockey
4~6