What does it sound like without the belt? You can’t run it long without the belt. I wonder about a lifter.

 

They appear to be the stock plugs but are torched



I have some new champion iridium 9201 I was going to put in

I'll put new plugs in tomorrow. Test fuel pressure and run shortly without a belt and upload a new video . Thanks again everyone for your help.

 

Replace with the proper plugs.
​​​​​​One less variable.
Ignition system on these cars does not enjoy iridium or platinum. It may cause no issues, it may cause issues. It may damage the ignition module.

It was designed for copper plugs at a particular heat range. Without being able to see the part number, may not be the correct NGK. Or in this case aftermarket AC delco 21025102.

Your cam cover gasket is in need of replacement. Oil has been collecting in the recess where the plug sits on the outside. That is why only the hex portion has the caked on burned material.

As for residue at the electrode, doesn't look all that bad. The only problem is the gap is way huger than it should be which is 0.040.

 

I agree with derf about the copper plugs. Mine always ran best on the OEM copper plugs. And I'm willing to bet the gap on the ones you pulled out is close to .060. How long has it been since the last plug change?

 

I am going back to the oil change. The latest batches of Napa Gold oil filter that I have bought are now made in Vietnam. The previous Napa Gold filters were made by Wix in North Carolina. We buy a lot of oil filters, my guys support a fleet of 125 trucks. All the smaller trucks get serviced every 4K miles. The three semis go 10K miles. I may go back to buying filters from the OEM. We use OEM filters on the 6.7L Ford Diesels. The International Dealer uses OEM filters on the larger trucks.

Did you use the same brand of oil and the same viscosity that you have been using? You have to be careful because the filters have been changing. The loud tapping in the first video sounds like lifter issues. I would change the oil and filter again after lifting the cam cover to investigate.

Years ago I had a Mazda loose lifters due to not using the manufactures spec oil.

 

Should have pushed harder for the answer..

Is it possible a massive amount of oil leaked from the cam cover gasket or elsewhere quite close to the time you did the oil change, and you drove around, unknowingly, with a very low oil level until then? Had you checked the oil level before draining the system? Does your SOHC burn oil?

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Both of my mid-90s coupes have had that clicking tapping sound for a minimum of 200,000 mi each. The last time I had a cam cover off, I rotated the engine by hand to ensure that all the lifters were functioning as advertised. I did not measure valve lash.

The difference is that they have it from startup to when you turn the key off. They don't start out silent and suddenly begin thumping.

Not saying it's normal or good, but it is extremely common on these engines, both SOHC and DOHC..
Has no effect on power in my vehicles.

 

I use
Valvoline 5w30 premium full synthetic extended oil
Fram synthetic endurance fe3614 filter
It burns about 1 quart every 1000 miles
I check it frequently with no sudden loss of oil

The valve cover was leaking when I bought it but I put a new gasket in it.

Today I put new stock copper spark plugs in, recleaned the EGR valve and redid the oil and filter with the same as mentioned above.

Went for the test drive and ran good for 30 mins no noise in the cab and then instantly loud tapping and power loss. No gradual increase the noise and power loss seems to be instant. I also had a fuel pressure gauge hooked up the entire time with no loss in fuel pressure

I pulled the valve cover off and the timing chain is tight . I don't know what else to look for . Could it be something with the injectors? Possibly tapping louder as they struggle to deliver fuel leaning it out?

Btw it's a manual transmission

 

Check for a a loose cam follower. You might have a lifter that either pumps or collapses and the valves do not open correctly. Both can cause tapping noises and loss of power. Please send a picture with the cover off if you can. Look at the valve springs closely to see if any of them look different from the rest. If it runs perfectly for 1/2 hour then it acts up it almost has yo be valve related. How long after it acts up does it have to sit to run correctly? If you can check compression right after it runs poorly it might tell you which cylinder to look at.

 

 

I'm a little out of my depth with the lifters I'm not sure what to exactly be testing for. As far as I can tell there's no play on the cam followers if I push down on them and all of the rockers have a little left to right play (1mm) but not crazy .

Here's a video. It's hard for me to turn it over and watch it alone. Maybe you can see something.

https://streamable.com/rnlx9m

As to your question about how long it takes to go away once cooling. Before I changed the oil I went for a 20 min drive and it started tapping and I came back and changed the oil. It tapped for like 5 minutes with the new oil and then faded away and then as the new oil got hot 15 t minutes later it started tapping again. It seems once the oil cools it goes away. I cant say for sure how long but it seems directly tied to oil temperature since it faded with the rest of the motor still hot except for the new oil that was now cold