Real loud tapping noise

[1badgs]

Hey guys, I just finished building my 7 bolt. The bottom end and head were done and put together by a shop here in town. I put the motor together and I forgot to bleed the lifters. It started up right away after a few cranks. and heard a real loud tapping noise coming from the engine, I figured I have bent valves, I did a compression test 4=0, 3=130, 2=127, 1=130. Now I haven't had any time to pull the head off but I just wanted opinions whether you guys think its bent valves or a rod knock since it sounds similar. The motor has all brand new forged internals and new springs, valves, and seals, this video was the first time the motor ever started. Was it possible to break anything on the bottom end? I have attached a link to the video of the noise, thanks guys


[ame=http://www.youtube.com/watch?v=pR-l85oahSo]Loud tapping - YouTube[/ame]

 

[Archer Fabrications]

Hummm do a conpression test again just incase the valves were
Open in #4, on a side note, why doesnt your fuel pressure reg have vac to it?

It doesnt sound like my lifters did and i didn't bleed them either. Are you sure timing was all correct? Mechanical and ignition?

 

[miliman13]

As some one who has lost 3x 4g63 to some type of bearing failure i can tell you, that is NOT lifter tick.

 

[91stocker]

Sure doesnt sound like lifter tick to me. Does it go away with or match rpm?

 

[1badgs]

The FPR doesn't have a line since it was a quick start up, if everything was well I would have connected everything fully. I checked compression twice on all cylinders, and they were the same. I know there is no way its lifter tick, my main questions are...is it bent valves hitting the top of the pistons because I didn't bleed the lifters prior to installing the cams? Can it be some kind of rod knock or any bottom end issues? and saying it is bent valves hitting, could that have messed up the bottom end ie: cracked pistons? The thing is guys, this video was the first time the car was started since it was built. So there aren't any miles on the motor or head. The timing was redone and checked again after that video...still had the same noise.

 

[jesterkid99]

Definitely sounds like bent or broken valves especially since you're seeing no compression

Definitely sounds like bent or broken valves especially since you're seeing no compression. It shouldn't be a problem if you don't bleed the lifters if you are cranking over the engine by hand first

 

[Archer Fabrications]

If the valves are kissing the pistons you can bet your ass they marked the pistons up.
Probably #4.

 

[miliman13]

Definitely sounds like bent or broken valves especially since you're seeing no compression

Definitely sounds like bent or broken valves especially since you're seeing no compression. It shouldn't be a problem if you don't bleed the lifters if you are cranking over the engine by hand first

I SECOND THIS, I didn't bleed my lifters when i did my rebuild, and they wouldn't cause your valves to hit, assuming you are mechanically timed. Perhaps the valves were not seated correctly upon assembly ?
Also its your cams that raise and lower your valves so lifters aren't a variable.

 

[1badgs]

Well I will have to tear it apart and see what the damage is, my main thing is as long as its not the bottom end and its the valves I'm okay replacing it. I spent too much money for such a silly mistake. I turned the crank by hand before installing the motor into the car, there wasn't any binding for what I can remember. But going back to what miliman13 said about lifters not being a variable, if that's the case why do people stress on bleeding lifters before install? If they are not able to compress when putting the cams in wouldn't they keep the valves open regardless since they cant compress even if the cams lobe over the rocker arms? Hence slapping the top of the pistons? Just trying to get an insight on it, but my main thing like I said its a lot easier to replace valves then to have to tear into the bottom end.

 

[raizen]

I would pull all the spark plugs and look to see if there are any indentations in the pistons. You should be able to check it with a good flashlight. If not you would need a scope. If you see damage to your piston(s) then you know its a bad valve. If everything is cool then pull the oil pan off. Check to see if the bearing cams for the rods are tight. If you can move them by hand then that's a problem.

 

[DSM1G90]

Taking the rocker cover off can show bent valves...and you gotta bleed them lifters for any interference motors.

 

[Archer Fabrications]

You do not HAVE TO bleed the lifters. Unless they are solid lifters they are all self adjusting.

I for instance didn't bleed mine and had no such problems as op. Same with two of my buddies. We all slapped them in assembily lube and put them in. Mine sat in the assembled motor for a few days before start up.

 

[Talon7038]

That honestly almost sounds like something got dropped in the the head. As silly as it sounds I have seen people drop small nuts and other stuff and miss it. That is running to well to have bent valves throwing 0 compression in a cylinder.

 

[1badgs]

Well I'm going to tear into it tonight, I'll keep you guys posted. But on another hand I watched some of jafros videos and he stressed to bleed lifters before install on an interference engine, otherwise you will bend valves, that's what he said. I also spoke to a local dsmer who has had plenty of dsms and he said the same thing. I won't know 'till it's apart. I appreciate the input guys.

 

[koryto2012]

Bleeding or not bleeding lifters, it's up to you. If they won't bring oil up into the head, and onto the valves, what do you think would happen? It'll cause them to seize up, and better hope it didnt seize up on a compression stroke.

 

[mitsubishikid]

I didn't bleed my 1g lifters when I did my rebuild, but I did use the starter to rotate my engine with no fuel, or spark for about a minute, I hooked it all back up fired it up and it did have a ticking sound, but it went away after I lightly revved it up to 2k three times, then I let it worm up fully and I never heard the sound again true story, but if anyone would feel more comfortable bleeding them go right ahead.

 

[Archer Fabrications]

I didn't bleed my 1g lifters when I did my rebuild, but I did use the starter to rotate my engine with no fuel, or spark for about a minute, I hooked it all back up fired it up and it did have a ticking sound, but it went away after I lightly revved it up to 2k three times, then I let it worm up fully and I never heard the sound again true story, but if anyone would feel more comfortable bleeding them go right ahead.

This.

Bleeding them is hype imo

 

[1badgs]

I get what you guys are saying, so I took it apart and checked the valves and nothing was bent. Nor was there any indication of the valves even kissing the pistons, everything looked good.The pistons are all nice and snug; The crank shaft rotates properly with no binding. I talked to a few techs from work, a long time machinist and they all right away leaned towards lifter tick. I told them I have never heard lifter tick be so loud but they all say its too consistent for it to be any bottom end noise. So I went ahead and ordered a new mls HG and I will be putting it back together soon. Im assuming they were just full of air even when they were seized. After I bled them they were empty of oil, I didn't prime them so we will see. I too myself have once rebuilt my head and didn't bleed the lifters and I didn't have any issues.

 

[d1978]

Word of advice for next time.... It's cheaper to get a bore scope than teardown an engine.... Saves a lot of labor and guessing.

 

[IQ685]

Coming from experience, lifters that are full of oil will bleed out over a short period of time, so even if you installed them completely full of oil to where you couldn't compress them at all by hand, once you stuck them in the engine and turned it over a few times within about 15 minutes they'd be blead out to their neutral location(zero lash, but no force placed upon the valve). The reason that I know is that I tried to shortcut when I was degreeing my cams and instead of making a solid lifter, I just pumped a standard HLA full of oil. Well, 2 barring over revolutions later I could see noticable loss in lift from where I started from, and I could also visably see the lifters compressing once the lobe started pressing on the rocker. So unless you've got oil pressure behind the lifter, it will bleed out. Now unless you were fast enough to stick a set of lifter in, put the cams in, time the engine and fire it all within about 15-20 minutes, not bleeding the lifters would not cause piston to valve contact. However that's my interpretation of "Bleeding a lifter" you could have meant that you didn't cycle any oil through them and installed them dry(I tend to refer to that as priming) I could see where that may lead to major lifter tick if there's no oil at all in the lifters. I would assume that would go away shortly though as soon as the oil system filled with oil and started supplying the head(and lifters) with oil. Possibly related question, did you prime the oil system before you stuck the timing belt on?(filled the oil pan and spun the oil pump gear until you saw a solid stream of oil coming out of the rockers with near no bubbles in the oil)

 

[98talonblack]

That sounds like mine did when i had no vacccume line on the intake after a rebuild i reattached every thing put slightly thicker oil in and it went away

 

[Wayne]

I agree with IQ685,

Now unless you were fast enough to stick a set of lifter in, put the cams in, time the engine and fire it all within about 15-20 minutes, not bleeding the lifters would not cause piston to valve contact. However that's my interpretation of "Bleeding a lifter" you could have meant that you didn't cycle any oil through them and installed them dry(I tend to refer to that as priming) I could see where that may lead to major lifter tick if there's no oil at all in the lifters.

. priming the lifters (soaking them in diesel fuel ) as per the shop manual will typically leave some air bubbles captive inside the lifter , as air is compressible and oil is not, this results in the lifter compressing more under force resulting in more valve lash andLESSvalve lift and a lot of tapping to go with it! Some times it can take More than just a few minutes for the lifter to naturally bleed with the engine running. so if you did not prime then lifters before installing them it can take an extremely long time for them to bleed. hence the tapping!

 

[1badgs]

IQ685 thanks for the advice. What I meant to say was I bled the lifters and put them in dry, the second time around. But it made the same exact noise as the video that is linked to this thread. The oil was primed and I know theres oil pressure because once I removed everything the lifters were full of oil since I bled them for a new HG. I have two questions to add to this though. I did that compression test after I put the lifters in the second time, why did I get a zero for a compression number on that cylinder? Maybe there wasn't enough lift since they were technically "dry" leaving valves open... The motor has a total running time of about 2 minutes or less. I didn't want to let it run with such a bad noise and no compression on the one cylinder. The head was decked and and so was the block, I originally installed an oem composite. Since I tore it apart again I figured Id get a thicker mls to makeup the different from the machining. The surfaces are still a mirror finish since it didn't run long at all.

 

[IQ685]

Running dry lifters would act in the exact oposite way that you're thinking, as there would be no oil in the lifter to counter act the force of the cam pushing down, so therefore you'd have less valve lift as the cam would compress the lifter before it would compress the valve spring. I also don't belive that you could have an issue of the valve not opening at all durring your compression test as the travel of the lifter is less than that of the lift of the cam. The only thing I can suggest without tearing into the engine would be go to an auto parts store and buy yourself a stethoscope and try to pin point where the noise is coming from.

 

[1badgs]

Behold guys...it was the timing trigger plate...it was bent a bit smh