Pontiac 400 that is about to make me pull my hair out.

[Carter]

OK, I have a Pontiac 400 that is about to make me pull my hair out.
Rebuilt 400 stock internals- comp cam something like (NOT EXACTLY!!) 246-269 with .444-.455 lift. High energy Comp -cam, I think. Small not lumpy.
Hurricane intake- Rochester carb rebuilt- HEI distributor.
Quick ratio rocker arms with polylocks lashed ½ turn past “0” lash. One at a time like a Pontiac as you turn the crank, with the spark plugs out starting a top dead center. When one starts to drop you lash the other valve.
Timing is set between 12-14 degrees at idle, for best start.
Problems:
Significant hesitation- (carb rebuilder says it is timing, because of timing gauge he has says timing is off?) when he corrects it car will not start.
Tapping in the motor, seems to be from lifters area rear right side worse then left. Gets worse when motor warms up.
When I remove the valve covers when the motor is running there is not oil being shot everywhere. There is oil shooting three inches from the first two rocker arms the rest kind’a dribble. They are all wet. But they are not shooting. NOTE- I have not conducted this test with the motor really hot. I will conduct this test this evening. Even though I know it will make a huge mess.
Sounds like a huge Exhaust leak that gets MUCH worse as I drive. The further I drive the worse it gets. I have driven this motor over 100 miles in a trip with no problems just noise. Noise is getting worse with each trip. motor has 1000-1500 total miles on it now.
Already checked:
External oil pressure gauge says 60+ lbs on startup. 35+ warm idle 40+ at highway speed and 15+ at HOT idle. Checked on rear of motor at oil pressure sending unit.
Valve lash 6X - 2 different ways
Replaced lifters
Replaced pushrods 2 were bent
Removed the timing cover and checked the timing dots are lined up. They are.
180 out with the distributor was correct
Replaced plugs and wires
Checked and rechecked all components on top of motor are installed correctly.
Checked for exhaust leaks replaced leaky header gasket.
Cut my hand once, smashed my finger twice- two different fingers. And burnt myself LOTS! UGGGGG!
I really am concern with this motor thing. It has me at the end of my rope and almost at the end of my allowance from my wife… Please help… lol. Thanks.

[BEEBE]

Hey bud, im sure there are some here that are pontiac savy but for the pontiac experts check out -

http://forums.performanceyears.com/forums/

and

http://www.pontiaczone.com/forum/index.php



im sure you will get alot of ponchobrainyacks to assist you on either one of these !!

Good luck hope you find somthin out. Keep us informed.

Peace

Beebe

[fbody_mike]

Are you 100% sure that the oil galley plugs were installed? Its not uncommon to be left out on a rebuild.

http://www.pontiacstreetperformance.com/psp/Galleyplug.html

[Nicks67GTO]

Its nothing against PT.com but go to the performance years board. A lot of the big Pontiac names post over there. They have helped me a ton with my GTO build. You would not believe the in depth knowledge on traditional Poncho stuff there

[ehummelman]

The Pontiac boards are great, and I also recommend them. However, you said you had 2 bent pushrods, you need to know what caused that. Second, you have some kind of problem with the rocker oiling. Oil should be coming out of all of them fairly evenly, not just a couple. Are the pushrods you replaced different than the ones you had in there, and are they the ones that are having a different oil flow through them?

[rohrt]

The Pontiac boards are great, and I also recommend them. However, you said you had 2 bent pushrods, you need to know what caused that. Second, you have some kind of problem with the rocker oiling. Oil should be coming out of all of them fairly evenly, not just a couple. Are the pushrods you replaced different than the ones you had in there, and are they the ones that are having a different oil flow through them?

X2

I would question if you have a flate lobe on the cam.
Are you using 1.6 rockers? Do they clear on the heads?
Adjustible valve train?
Doesn't sound like you indexed the cam.

I have a custome made priming tool that I use on my motors and I check for good oil flow on each rocker before it goes in the motor. I would be worried that an oil passage is partially pluged and not pumping up the lifters.

[sam 74]

you need to find out why you bent pushrods, if you're not getting the oil flow needed to the top end that'll cause noise and premature failure of the rockers. if you have good oil pressure then theres something clogging your passages, at somepoint, assuming the galley plugs are installed. i'd probably not drive it anymore until this gets figured out. on another note you may want to see if you bent any valves on the cylinders that had the bent push rods, also are your valve springs correct and installed correctly, no bind or anything.

[Carter]

I would question that too. (Flat lobe) but I looked the cam over the last time we have the valley pan off. It looked intact, and there were no shavings in the pan or filter to mention.
I don't know what ratio the rockers are? But they are working with stock pushrods. The two I replaced were the same size as the ones in the car.
There is not an adjustable valve train that I know of.
I don’t know if they indexed the cam or if that is even a cam that needs indexing.
I didn't install the cam or anything else in this motor- so I really don't know. But that galley oil plug is concerning me most right now. I hope that’s not it. But it would be nice to finally know what the problem is.



would question if you have a flate lobe on the cam.
Are you using 1.6 rockers? Do they clear on the heads?
Adjustible valve train?
Doesn't sound like you indexed the cam..[/QUOTE]

I have a custome made priming tool that I use on my motors and I check for good oil flow on each rocker before it goes in the motor. I would be worried that an oil passage is partially pluged and not pumping up the lifters.[/QUOTE]

[Carter]

My next thought is to take the pushrods out again and check each for oil passage. Then I want to start the motor and check for the noisy lifter with the valve covers off.
Oh, note. Just found out -so called Mechanic- replaced lifters, didn’t soak them to fill with oil. Might have collapsed lifters on startup? I think they might re-set themselves if you run the motor. We should be able to find problem lifter with noisy rocker. Reduce pressure of nut? It pumps up on its own? I don’t know. We are way past my mechanical knowledge and troubleshooting skills. I have dumped enough money into this motor, I could have bought a different motor… UGGG

[Carter]

:banghead:59600

[67bird]

First thing is were the lifters soaked overnight to fill them with oil? Has the motor set long since they were installed? I did the same thing with my Olds motor when I put adjustable rocker arms on it. I bent pushrods due to lifters being low and when they pumped up lash was off. They were way tight and bent the pushrods. Second of all you didn't mention valve work or cylinder head work. Where the heads shaved? Was the roller pattern checked on valve stems? I would check coil bind. I would also invest in Jim Hand and Rocky Rotella's books on Pontiac engines (you can probably find Jim's used for alot less, you may have $40 in both). You may find something in reading them that you aren't remebering here. I think that if the oil gallery plugs were out you would have no oil pressure or less when hot.

[Carter]

lifters, not soaked. just found thats out. yes there is wear marks on the value stems. is thats bad? thought it was ok if it was even and consistant. dont know about headwork. it stinks to have so many unknowns. thanks for book sugestions. ill look into that.


First thing is were the lifters soaked overnight to fill them with oil? Has the motor set long since they were installed? I did the same thing with my Olds motor when I put adjustable rocker arms on it. I bent pushrods due to lifters being low and when they pumped up lash was off. They were way tight and bent the pushrods. Second of all you didn't mention valve work or cylinder head work. Where the heads shaved? Was the roller pattern checked on valve stems? I would check coil bind. I would also invest in Jim Hand and Rocky Rotella's books on Pontiac engines (you can probably find Jim's used for alot less, you may have $40 in both). You may find something in reading them that you aren't remebering here. I think that if the oil gallery plugs were out you would have no oil pressure or less when hot.

[Carter]

oil is flowing through the pushrods now, lots of smoke. flowing well when warm all rockers.

[Carter]

That's enough for tonight, car started overheating. Sometimes I really hate this car.

[sam 74]

you have an adjstable valve train so you need to make sure your valve lash is correct, you'll get noise from incorrect settings. if the guy that worked on this wasn't in the know about soaking the lifters then i would assume he probably doesn't know how to set lash correctly either.

[ehummelman]

Very frustrating, we can all probably relate. Stick with it though, it'll get there. You could always pull the engine and have a "good" shop go through it and correct whatever needs correcting. It could be money well spent to save your sanity.

[Carter]

Updated my info here and asked this set of questions on Performanceyears forum.

I didn’t rebuild I bought like this so there are a few unanswered questions unfortunately.

Rebuilt 400 stock internals (I think)- Comp Cam CL51-221-4.
With Harland sharp 1.65-1 roller rocker. With polylocks lashed ½ turn past “0” lash.
push-rod length 9.136- 5/16

Hurricane intake- Rochester carb rebuilt- HEI distributor.

Timing is set between 12-14 degrees at idle, for best start. I have no idea what the other timing number is- or even how to test that number.

This car sat for 1 yr, while being painted. It was started and ran very little. Water got into the motor; I drained and cleaned as much as I could. Could still be rust in the motor? I changed oil 3 times within 1500 miles.

Problems:
Significant hesitation- (carb rebuilder says it is timing, because of timing gauge he has says timing is off?) when he corrects it car will not start.
Tapping in the motor, seems to be from lifters area rear right side worse then left. Gets worse when motor warms up.

Sounds like a huge Exhaust leak that gets MUCH worse as I drive. The further I drive the worse it gets. I have driven this motor over 100 miles in a trip with no problems just noise. Noise is getting worse with each trip. Motor has 1000-1500 total miles on it now.
I am not a mechanic but it sounds like to me the intake and exhaust on one cylinder is open at the same time.


Already checked:
External oil pressure gauge says 60+ lbs on startup. 35+ warm idle 40+ at highway speed and 15+ at HOT idle. Checked on rear of motor at oil pressure sending unit.
Valve lash 6X - 2 different ways
Replaced lifters- auto zone replacements.
Replaced pushrods 2 were bent- tightened the wrong intake /exhaust. OOPS.
Removed the timing cover and checked the timing dots are lined up. They are.
Checked if it was 180 out with the distributor, it was correct. But the Vacuum advance on the distributor is to the passenger side of car? Problem?
Replaced plugs and wires
Checked and rechecked all components on top of motor are installed correctly.
Checked for exhaust leaks replaced leaky header gasket.

I really am concern with this motor thing. It has me at the end of my rope and almost at the end of my allowance from my wife… Please help… lol. Thanks.

Questions:
Does this cam need to be degreed? If it wasn’t what could be the result?
When setting timing where the vacuum gauge says it should be the car will not start.
Is this a significant cam? Should I hear it?
If I used cheap-o lifters they might be the wrong part? Chevy part used in Pontiac- I guess there is a difference?
FYI. It was ticking this way with the comp cam lifters too.
The car has started overheating again. Huge aluminum radiator with dual electric fans from 2002 trans am.
If over tightened poly-locks and rocker arms
Are the pushrods ok with the rocker arms?
Is it ok to have 1.65-1 rocker arms?
Timing should be adjusted at idle? Someone told me 1500 RPM. That would make a difference.
Having the car timing incorrect could cause overheating issues and lifter noise… I think.
This car runs really bad. It will hardly spin the tires most times. Its pretty sad compared to every other 400 I have ever had.

[Roadbuster]

Updated my info here and asked this set of questions on Performanceyears forum.

I didn’t rebuild I bought like this so there are a few unanswered questions unfortunately.

Rebuilt 400 stock internals (I think)- Comp Cam CL51-221-4.
With Harland sharp 1.65-1 roller rocker. With polylocks lashed ½ turn past “0” lash.
push-rod length 9.136- 5/16

Hurricane intake- Rochester carb rebuilt- HEI distributor.

Timing is set between 12-14 degrees at idle, for best start. I have no idea what the other timing number is- or even how to test that number.

This car sat for 1 yr, while being painted. It was started and ran very little. Water got into the motor; I drained and cleaned as much as I could. Could still be rust in the motor? I changed oil 3 times within 1500 miles.

Problems:
Significant hesitation- (carb rebuilder says it is timing, because of timing gauge he has says timing is off?) when he corrects it car will not start.
Tapping in the motor, seems to be from lifters area rear right side worse then left. Gets worse when motor warms up.

Sounds like a huge Exhaust leak that gets MUCH worse as I drive. The further I drive the worse it gets. I have driven this motor over 100 miles in a trip with no problems just noise. Noise is getting worse with each trip. Motor has 1000-1500 total miles on it now.
I am not a mechanic but it sounds like to me the intake and exhaust on one cylinder is open at the same time.


Already checked:
External oil pressure gauge says 60+ lbs on startup. 35+ warm idle 40+ at highway speed and 15+ at HOT idle. Checked on rear of motor at oil pressure sending unit.
Valve lash 6X - 2 different ways
Replaced lifters- auto zone replacements.
Replaced pushrods 2 were bent- tightened the wrong intake /exhaust. OOPS.
Removed the timing cover and checked the timing dots are lined up. They are.
Checked if it was 180 out with the distributor, it was correct. But the Vacuum advance on the distributor is to the passenger side of car? Problem?
Replaced plugs and wires
Checked and rechecked all components on top of motor are installed correctly.
Checked for exhaust leaks replaced leaky header gasket.

I really am concern with this motor thing. It has me at the end of my rope and almost at the end of my allowance from my wife… Please help… lol. Thanks.

Questions:
Does this cam need to be degreed? If it wasn’t what could be the result?
When setting timing where the vacuum gauge says it should be the car will not start.
Is this a significant cam? Should I hear it?

If I used cheap-o lifters they might be the wrong part? Chevy part used in Pontiac- I guess there is a difference?
FYI. It was ticking this way with the comp cam lifters too.
The car has started overheating again. Huge aluminum radiator with dual electric fans from 2002 trans am.
If over tightened poly-locks and rocker arms
Are the pushrods ok with the rocker arms?
Is it ok to have 1.65-1 rocker arms?
Timing should be adjusted at idle? Someone told me 1500 RPM. That would make a difference.
Having the car timing incorrect could cause overheating issues and lifter noise… I think.
This car runs really bad. It will hardly spin the tires most times. Its pretty sad compared to every other 400 I have ever had.

Something basic that catches people who are not familiar with a Pontiac. The distributor turns in the opposite direction that a chevy does.

Chevy parts in a Pontiac? don't know do the part numbers match?

1.65:1 rockers are not overly large on a Pontiac, 1.6:1 are stock and the Ram airs used 1.7:1.

Do you have any vacuum leaks? Make sure your lines do not leak.

Good luck! you will get there!

[Tom Welch]

I suggest checking compression, a leakdown test and a block test, a block test kit can be purchased at NAPA, check distributor shaft end play, shouldnt be more that about .025. Check the rebuilt carb for throttle shaft play, this alone will play hell with idle characteristics and timing the engine. Verify that the cam isnt wiped, get verified pontiac lifters, call Jim Butler or similar outfit for these, most parts stores dont have the correct lifter as has been noted. Do you have the correct heat range plugs? Pontiacs are sensetive to this, get champion J12YC, they will work. Start the car at night and watch the engine for 'leaking' spark plug wires, this will drive you nuts, too. Good luck.

[goatsamoto]

Hi. Read your tails of pontiac wows and with the specs that you posted, It seams that you have multible issues that may need reviewed and addressed
1. Heads and deck resurfaced, was the pushrods lengths checked ??? that much iron removed and a larger cam profile most likley require a set custom Pushrods
2. 1.65 rocker arms will not work on a standard pontiac motor unless you elongate the pushrod inlet holes in the heads
R A IV are done at the factory.
3. Did you check valve to piston clearances?
4. Pontiac are very sensitive to distributor possition. Vuccum advance should be on the driver side of the engine.idel set at 750/850. Rpms with advance vaccum line discon nected at carb and blocked off. Set at10/12 degrees and 32/36 at 2800rpms
One suggestion I seen someone post, was to locate a book called " How to Build Max performance pontiac V-8s" writen
by Jim Hand. It would best the 20 bucks you ever spent on your Pontiac Motor.
Thx good luck, Goatsamoto

[Pt109]

I see its been quite awhile and hope you have it figured out by now. I had an extremely aggravating issue with a 460 ford in my 4x4 years ago. Hesitation was bad, 3 new carbs, backfired thru carb, hence the replacementswouldnt run right, idle worth a damn and tons of other things. I also had the vacuum lines all screwed up. Had some of the best mechanics look at it and not one of them could figure it out. Long story short the diaphram in the brake power booster had a pin hole in it. Replaced that and it never ran so good. It sure did some strange things before we got that figured out. Just thought I'd put in in for another thing to check. The little things cause the biggest problems. Good luck.

[MonzaRacer]

Pontiacs with low compression is flat tops open chamber cheads can handle as much as 60 deg total timing. Closed chamber heads will not work with low duration cams ask me how I know!
Also older high Comp heads may take shorter push rod, also you should measure max amount of lift the springs,retainers and guide boss can handle, many Pontiac heads need help to handle higher lift cams.
On my 400 I ran my base timing at highest notch on cover like 14-16 I think, still have it may need to look. As long as it cranks OK hot and doesn't surge at idle its OK I like to use stock HEI with stock weights and lightest Mr Gasket springsxcfron curve kit. Get everything running well there, then hook vac advance to manifold vacuum then retune idlespeed and mixture.
Oh and Pontiac lifter will work in sbc but sbc lifters will drop out of the lifter bore, tip sideways and break lifter bores, the weakest point of Pontiac block. Hopefully you don't have older pre 65 block, different animal and doesn't handle later parts well.
Many stock casting heads won't take over 500 lift with certain retainers.
Oh and if you have headers dump the gaskets and go find a caulk type tube of dap/Dow Corning 50 yr clear silicone, slathers it well and install grade8 bolts with lock washers.
And if cam wasn't broke in properly you may have flat cam! When installing flat tappets cams use a moly based cam lube use high zinc oil like Brad Penn, Comp cams over counter truck oils to use are either She'll rotella t or Chevron Delo.