3.0 Tapping Noise

[81dmc]

So I finally got my 3.0 running. At 200*F, I'm getting 14-17PSI oil pressure as idle. At 2000, it's 55-60psi. Looks like that's book value for a 3.0.

Now I'm having a tapping noise. I put new solid rockers and reused original 3.0 cams when doing rebuild. Now I don?t know if my tapping is the rocker, I mean it certainly sounds like it, but could it be something else? I did run it at 2500 rpm the best I could. Maybe it's time to reset lash?

https://www.youtube.com/watch?v=Xn-M_Fm71mk


Also, getting a vibration at 1500 and 2500 rpm. I think the vibration is from the spec 1. It shakes at those RPMs.


The car currently sounds like one of my diesels lol.

[Jaybaybay]

Any particular reason why you didn't want to stick with the original hydraulic setup? One of the reasons I liked going to the 3.0 was the automatic lash adjustment. I'd run it with the valve covers off and see if you can pinpoint the noise source. If it ran quiet before the switch then I'd say that's where your problem lies.

The noise in the end of the video next to the block/front cover sounds like rpm (crankshaft) not camshaft speed to me.

[81dmc]

Any particular reason why you didn't want to stick with the original hydraulic setup? One of the reasons I liked going to the 3.0 was the automatic lash adjustment. I'd run it with the valve covers off and see if you can pinpoint the noise source. If it ran quiet before the switch then I'd say that's where your problem lies.
This engine never even ran before the switch. It had a cooling system mess and pitted cylinders when purchased from junkyard. Then some of the hydraulic lifters were frozen with no reliable replacement available. So it got new solid rockers, new liners/rings, new chains/guides, and new bearings.

I was still unsure whether to run those old lifters, but Josh B from DPI advised me to stick with the solid setup for reliability.


I wish I could run with covers off, but it would shoot oil all over the place..

[Dickey]

I use one of these for mechanical taps because I do not hear very well and I find the acoustic isolation is really handy:

https://www.harborfreight.com/mechanics-stethoscope-63691.html


Prior to becoming an old man yelling at clouds, I would just use a long socket extension and put my ear to one side with the metal touching the engine somewhere on the other.


Similarly, since I cannot hear very well, I also take a length of 3/8 fuel line with one end to my "good" ear and put the other over each exhaust port because I can no longer hear the difference between a bad exhaust leak and a loose rocker arm as most of my engines have pushrods. The rubber quells a lot of the mechanical noise from the engine and an exhaust leak is really loud on the port where it's coming from should that be the source of the racket.

[Delorean Industries]

Check rocker adjustment and listen to injectors. A loud injector can reverberate through the cylinder.

[81dmc]

Check rocker adjustment and listen to injectors. A loud injector can reverberate through the cylinder.
Rog. Going to check lash today. I actually pulled each injector plug one by one with no change to noise.

Going to also reduce my plug gap from .046 to .030 as I think the COPs in series might be giving me some lumpiness as well.

[81dmc]

During valve adjustment. Cams look good to me. Some rockers were a little loose.
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After. Starting to think I have an exhaust leak, so I ordered new manifold gaskets.

https://www.youtube.com/watch?v=5Lhh2PV53-E

[Ron]

$.02

Hard to say, but the tic(s) sounds quieter in the 2nd vid to me.

Since you think it may be exhaust leaks, try pulling the plug wires one at a time while it's running...

[81dmc]

I'm starting to get the feeling that my cam timing is off a tooth.

Why? Well manual calls for intake valve to begin opening at 14* BTDC. Cylinder 1 and 5 TDC can be referenced using TDC mark on crank pulley, and thankfully, I can see intake rocker for #5 clearly from oil filler.

I'm not seeing the intake valve beginning to open until after TDC.

I made a video. I call out the degrees BTDC for #5. What y'all think?

https://www.youtube.com/watch?v=cAJguePUQxA

[81dmc]

So I pulled the timing cover through the night and retimed, and it's the same. It was timed right from the get go.

I guess I'll replace exhaust gaskets and just live with any noises that remain unless anybody has any ideas?

[81dmc]

Ran some more today, and can definitely hear intermittent and very slight misfiring pops from exhaust.

[Bitsyncmaster]

Ran some more today, and can definitely hear intermittent and very slight misfiring pops from exhaust.

I always though my engine had the same "very slight misfiring pops". But I put some software into my idle ECU to detect a misfire which checks every two ignition pulses and triggers if that time is outside +/- 50 RPM and my engine can idle for 5 minuets without any hits. So that popping sound you hear may be something other than a misfire.

[MrChocky]

I always though my engine had the same "very slight misfiring pops". But I put some software into my idle ECU to detect a misfire which checks every two ignition pulses and triggers if that time is outside +/- 50 RPM and my engine can idle for 5 minuets without any hits. So that popping sound you hear may be something other than a misfire.

Obligatory sewing machine sound effects.

[AugustneverEnds]

Does your car have a catalytic converter? Perhaps it's partially plugged? The manifold gaskets might be beginning to leak. Fun job!

Is your EFI mapping dialed in? Maybe the mixture is slightly off.

[81dmc]

I always though my engine had the same "very slight misfiring pops". But I put some software into my idle ECU to detect a misfire which checks every two ignition pulses and triggers if that time is outside +/- 50 RPM and my engine can idle for 5 minuets without any hits. So that popping sound you hear may be something other than a misfire.
Maybe you're right. I just also get some vibration when it's doing the micropops. I may run a test harness and swap to the eagle premier coil pack instead of COPs.

Or maybe I got a bad EDIS module






Does your car have a catalytic converter? Perhaps it's partially plugged? The manifold gaskets might be beginning to leak. Fun job!

Is your EFI mapping dialed in? Maybe the mixture is slightly off.
Cats are new DPI high flow, and I have new manifold gaskets on order. I probably toasted the gaskets as I ran the car for about an hour then I found I forgot to tighten the header studs :facepalm:.

Overall, mixture isn't done yet, but in the video, it was idling around 14 afr and 14* of timing. I messed with the AFR and it didn't effect how it was running much.

[81dmc]

Tried the Monaco coil pack with no change. Drained oil after 35 miles of driving. Oil had a definite dust of metal. Was a 10w30.

I changed it to VR1 20w50 and the idle oil pressure went from 14 to 22 psi. Big improvement there. Cam lobes still look good from oil fill hole.

I will experiment with the exhaust gasket, EDIS, and injectors next to determine my issue. Will also try running with only headers to see if that?s my vibration.

[Ron]

Did you try pulling the plug wires one at a time?

[81dmc]

No change pulling injectors one at a time. Also tested injectors and spray looks good.

I read somewhere online that the hydraulic cams are different then solid lifter cams. Anybody know if this is true?

[Ron]

No change pulling injectors one at a time. Also tested injectors and spray looks good.

I read somewhere online that the hydraulic cams are different then solid lifter cams. Anybody know if this is true?
Good, pulling either one should change the sound if the problem is exhaust gaskets, usually.

Solid lift cams typically have faster ramp speeds, lift higher, and need stronger valve springs.

[81dmc]

I wish there were performance cam option for the 3.0. I would?ve put a set of cams in this if that were the case.

Hopefully most of the noise goes away with break in. I guess I?ll find out if it eats the cam or not.

[81dmc]

So...found the source of the noise.

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Crappy Fel Pro exhaust gasket didn't work too well. #4 was the worst and it makes sense as most noise was from that area.

New DMCH gaskets coming Wednesday. Bought from them as I needed a new bowden cable and a pretty DMC sticker to go on 3.0 cover.

Maybe Josh Bengston could answer this? Should I add more manifold studs, or is it fine with the 2 for each cylinder?

[Timeless]

Good news it's not a more significant issue. For over 10 years I never had issues with FelPro gaskets at my shop although, they could be made with subpar quality now. (i.e. China)

[Delorean Industries]

We recommend four to a cylinder. Glad you found the issue!

[Josh]

if your flanges are flat, there is no reason to have more than two studs per cylinder. You can install more studs to try and flatten out a warped flange, but it really should be milled down which can be done by most machine shops. I would check it with a straight edge before you throw on new gaskets.

Having four studs a cylinder is not common practice with other engines, it gives more failure points (rusted/snapped studs) and makes it more difficult to install the headers.

[81dmc]

Aaaaand spoke too soon. Put new gaskets and noise is still there. :confused:


Maybe it's oil coming past rings making that noise? Or just valve train?

I'm about to to give up, put some serious miles and see if it blows or eats a cam.

[81dmc]

Also, for Josh B.

I started it without cats connected and no vibrations at all. Very smooth. Hook cats and tighten band clamps and vibration returns.

[81dmc]

I?m hearing most of the noise where all the tubes meet at collector. Going to check with vacuum cleaner and soapy water when it cools down.

[81dmc]

So even with brand new gaskets, it still leaks! Anybody have an idea how this can be fixed?

https://www.youtube.com/watch?v=Xnz9igwVwi0

[81dmc]

Header is warped about .018 of an inch:shocked:

Going to call DPI tomorrow to see best course of action.

[Delorean Industries]

We would run the flange across our surface grinder, fuse dress the ports and pressure test on our platen fixture. These are the final steps of making a header in-house. The warpage of .018 on a flange would be considered nominal. It is not much and would draw closed against a quality gasket and two prepped surfaces. Is there is any pitting on the cylinder head port sealing areas? Four bolt flanges are the aftermarket header manufacturer’s ideal situation. The idea of being able to secure a port in such a fashion gives unbelievable levels of excitement in the aftermarket industry. While an OEM manifold may work fine with two points, the thermal expansion characteristics of a flange with .065 wall tubing moving under heat loads are very different by contrast. Headers bolted opposite each other exhibit a pringle event during various engine loads. This can be visualized by setting a pringle chip on a flat surface. Regardless of how the chip faces, the two edges contacting the surface represent the flange bolted point. The two perpendicular edges not contacting represent the section of the flange not held around the port. This is a solid visual representation of how the joints function under various heat loads over cycled application use. Not having clamping force evenly spread around the sealing joint is an issue.

Edit:
Also, just saw the above video after logging in. That is a very low-quality single-layer exhaust gasket. Would recommend using a better gasket. Where is that from?

[81dmc]

So I have about 150 miles on the engine now and I pulled the oil cap to find this. Running MTC rockers. Pictured is an intake lobe.

Is it me, or does this cam looks no bueno?
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[Delorean Industries]

Would appear to be a wear issue. Pull covers to inspect further.

[81dmc]

https://www.youtube.com/shorts/uvhvsXOtvx4 (https://m.youtube.com/shorts/uvhvsXOtvx4?feature=share)

Quite a bit of leakage past #6 exhaust valve. What you all think? Does it seem excessive?

I don?t know about automotive, but on aircraft engines, we usually punch the valve and worse comes to worst, we lap it to remove these kind of leaks.

[Jaybaybay]

Punch the valve? what does that entail? You're also sure the lobe for that valve is on the closed portion? Where are you located in FL?

I also should've reread your earlier post about the history of your engine, mine also came from a junkyard and had a little bit of leak down before running. Others online chalked it up to slight corrosion on the valves/seats and said from other junkyard engines to just let it rip. I figured what the hell If it doesn't work then I would just take it apart but so far so good. Haven't verified my numbers were better but it runs great to me.

[81dmc]

Punch the valve? what does that entail? You're also sure the lobe for that valve is on the closed portion? Where are you located in FL?

I also should've reread your earlier post about the history of your engine, mine also came from a junkyard and had a little bit of leak down before running. Others online chalked it up to slight corrosion on the valves/seats and said from other junkyard engines to just let it rip. I figured what the hell If it doesn't work then I would just take it apart but so far so good. Haven't verified my numbers were better but it runs great to me.
Punching means tapping the valve open from the top to see if carbon is preventing the sealing. If that doesn't work, lop the paste in and start spinning. Of course, I can't do that without pulling rockers which means pulling engine?

My heads were O/H by a reputable machine shop in Houston, so it shouldn't be leaking, but of course sh*t happens.

[81dmc]

So it?s obvious, even though I have an ?exhaust leak?, it doesn?t leak while running.


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So leaky #6 exhaust valve causing tapping? At this point, I don?t know what?s going on anymore.

[81dmc]

So I've come to the conclusion the exhaust side tick is combustion noise. The RH no longer does it as I wrapped a couple pipes to protect oil filter and alt from extreme heat. And that exhaust valve went away after tapping with hammer while cylinder was pressurized.

Also, my valve train tick/tap is slowly going away as it breaks in.

As for the marks on the cam, I found they are just shiny areas. I ran my fingernail over it and was unable to feel any damage.


So I guess good for now.