So when I fired up my car not too long ago. After about 20-30 seconds of idling my engine began making these weird grinding/metallic sounds. It almost stalled out but then it did the rev up to over 1000 and eventually levelled out like normal. The car drove like normal, I checked the dipstick and it's full and the oil is still gold. I drove it for only 10 or so minutes but got it up to 80 with no problem. No power loss, no funny nosies while accelerating or cruising.

However, at idle, the second video is from when I got to my destination and you can here these popping sounds coming from the rear of my engine. I can hear them from the rear of the car too.
The first video is the metallic noise from startup just at the end of it happening (after the idle smoothed out)

This video is after the 10 minute drive, the popping noises:

This is the noise from the mufflers

 

Hmm, sounds like a ticking lifter / exhaust leak / vacuum leak from my phone. Maybe a mechanic's stethoscope (or hose in your ear if we're gettin fancy) could help pinpoint it? Also, does the idle ever go lower than that? My warm idle is like 650rpm.

 

I just drove it again. This time on start up it didn't bog down. I'm suspecting that might be do to the bad MAF Burnoff Relay (which I've ordered but still waiting on) as it was raining when I took those videos. However, the noises were still there. I'm betting it's a mixture of exhaust/vacuum leak. I looked at my header gaskets and they look bent out of shape with gaps. Also sometimes when I brake really hard my engine kind of bogs down, which leads me to think vacuum as well.

I'll order a stethoscope just to make sure it's nothing internal.

 

Update. I did order some parts since my last post. Still waiting for them to arrive. My car is making this strange vibration now when I rev it. It's almost like the motor hesitates and then it revs. Anyone know what this could be?

 

That's a misfire for sure. And your engine idles at 800? That's not right either. The possible problems are a long list. Check plugs, check vacuum leaks, check wires, listen for internal problems, fuel pressure etc etc etc. DON'T THROW PARTS AT IT. Learn to troubleshoot. People here are always willing to help and search, there are 1000s of people on here that have had similar problems and have valuable information for you to learn too.

 

I did my plugs, wires, cap, rotor and ignition coil almost 1 year ago (December 2020). Could they be bad already? I used NGK plugs, Thunder Wires, Delco Cap, Rotor and Coil.
I've replaced every vacuum line on the car as well. I'll try again tomorrow with carb cleaner and see.
I've owned this car 8 years and can trouble shoot most things but other things even using this forum are hard to figure out. I've searched passed threads but couldn't find any with videos or sounds similar to mine. That's one of the reasons I film the symptoms of my car, so other people can find them too.
In 8 years since I've owned my car, my car has always idled 800 RPM in Park/Neutral and around 600 or so in OD. Your the first person to ever say that's a problem.

 

My point in my last post wasn't to make you feel attacked and get defensive. My point is you need to think like a troubleshooter. When you have such a problem it's more difficult for us to find anything out without being there and getting to work. Video speaks a lot but even the best mechanic has to troubleshoot, they can't get all the information you need to say whats wrong with it from standing there.

I don't think anything in your ignition wore out or anything. I mean check them. Pull plugs. Is one of them different than the others? Leads to think you have a problem with one cylinder. That brings the troubleshooting to be more direct.
Are they all black or sooty? Well now we have to think what can effect all cylinders.
Use the stethoscope you have coming to locate the source of your noise. Could be an unrelated exhaust leak for all we know watching on the internet. Could also be severe internal damage. Bad lifter or spring?....the spark plug check may help us determine that by seeing a plug that's different.

Vacuum leak checking is more difficult than it seems on a tpi. Carb cleaner is basically useless to get to 40% of the places that can leak. I always suggest investing in either making your own smoke machine with a paint can and a cigar (do a google search to find more info) or get a cheap one on Amazon. I paid $80 for a simple, practically homemade smoke machine. Or get a shop to smoke test it and show you where your leak is coming from. I wouldn't drive that car anywhere as it's running now so I'd leave the smoke test out of it for the time being, but they are invaluable when finding a leak. A leak could be the cause of your high idle. Or it could just be how someone readjusted it. Neither here nor there at this point but it is something you want to note when troubleshooting, could be unrelated, could be directly an affect from whatever is wrong. When troubleshooting, it's helpful to get any piece of connected information.
So let's start troubleshooting. Get us more information, we'll help.

 

Sorry if I came off as defensive, I was just explaining what I've done so far. That's my bad then. I checked all of the plugs this morning. All of them look normal. No build up, no wear. Wires look fine.

I'm still waiting on my engine stethoscope. I'm praying it's not lifter tick. I've changed oil on this car every 3 to 4 month and always used full synthetic.

 

Did you take a picture of the plugs? that can help. Make sure none of the porcelains are cracked.
A chunk of 3/8-ish hose can be used as a stethoscope in a pinch if you want to start listening now. Listen at the valve covers. If the drivers side seems louder, pull that valve cover and see if there's anything abnormal. Take pictures for us to analyze.

 

I'll pull the plugs again later. I should have took pictures. I was trying to get it done since it's a pain in the *** with headers.

I'll try the 3/8 hose trick. I've posted scans of my car using turner pro in the past and no one has ever responded to them. I'll post another scan in a couple of hours.

 

One last thing I wanted to mention. The misfire seems to clear up above 30 or so MPH. Once I get passed that the car runs smoothly. It seems to go away after long drives too. Not sure if that means anything or not. I will post a scan in a few hours.

 

Here is my turner pro log. Let me know if anything looks off.

 

Here is a driving log I took.

 

I'm on a phone, I don't have a prayer at looking at datalogs. Sorry I can't be more assistance there

 

No problem. Tomorrow if it's not raining, I'll ohm the injectors.

 

Could someone tell me if I am testing my ohms correctly? I tested Cylinders 1,3 (driver's side) 2 and 4 (pass side) and I get 0.09. Are all 4 that bad or am I testing wrong? I set my multimeter to 200m and touch the two metal tabs with the prongs.

When I set it to 200k, 20k, etc. I only get the 1 or the I.


Injector 1

Injector 3

 

Never mind I "fixed" my multimeter. Wrong 200 setting...


All injectors were around 16.5. It dropped before I hit old.

I did notice this.. hmm... I think I need a new set of wires and some boots...

 

The wire looks pretty split. It's cylinder 2. These are Taylor Thunder Wires I ordered a year ago. For now I'll run out to the auto parts store and replace that wire and see if it fixes my problem. I probably should have ordered boots with the wires...

Is it ok to mix wire brands? Since more than likely the store will be Delco.

 

You *can* mix them, not the end of the world. Not ideal but will help eliminate that one wire from being a problem.

 

The mixing would be temporary. I'll be the set and replace all of them later this week. I just wanted to put one on there to see if that cures the problem. It's crazy, my last set I didn't run boots with them and had no problems.

The picture doesn't do justice to how split that wire looks.

 

Ok, so I replaced all of the spark plug wires with ACDelco it made a huge difference in noise reduction, vibration and misfire. It was really odd though. After I first changed wires, the car would not idle. It kept wanting to stall out the first several times I started it. I kept checking the wires, made sure the firing order was right and then finally it started and idled normally.
I still hear some noise and a metallic/grinding sound. I'm wondering if that is the header gaskets. I did notice my idle in park slightly lower. It is at 750ish now and more stable.

Also something mild. But I noticed that my temperature was climbing quicker. I don't know if that was from starting it a dozen times and it stalling, then it finally idling, then a very slow 5 minute drive at 40 and then more idling for 5 minutes in the driveway. It was already at 220 and my fan kicked on.

My only complaint is the AC Delco wires are so damn long. I need to by more wire looms. Also two of the wires have straight boots on them and that sucks with headers. I might leave them on their for a few weeks and replace them with MSD or something.

Anyway here are two videos:

 

Glad you found your solution.
the temperature thing wouldn't bother me. I would just make sure tye thermostat is opening and note it. It may be pertinent in the future but currently isn't abnormal.
Your noise could be an exhaust leak or a noisy injector judging by the sound. That's what stethoscopes are for.

 

Still waiting on the scope and the header gaskets. So much for quick prime delivery...

I'm going to drive the car after Rushhour is done and watch the temp gauge. I know I replaced the thermostat almost 2 years ago with a 180*. I'm going to watch it closely. Volts wise all injectors were at 16.5 but they could be getting old. I'm 99% sure they are original.