engine knock bad!!

[JRSVIPR]

i was just reading the thread about Bone pulling his motor. is there any way that a rod is bent because the crankcase was preassurized?

Probably not, Most that would happen is blown seals.

 

[WOT]

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Oil should not be used in a compression or leak down test.

Oil can be used after an initial "DRY" test.

The oil will artificially seal the rings and negate the results of the test if done first.

Actually, you are absolutely correct -- I appear to be mixing my methodologies (might be the beer, but the jury is out on this one). If you are detecting excessive leakage but are having trouble determining if it is mostly the rings or the valves, a couple of squirts of oil will artificially seal the rings and will eliminate them from the equation. But it usually will not aritificially seal a leaky valve as the oil just goes down around the piston.

So, for instance, lets say you have one cylinder with a high leak-down percentage (40% or so) and you can hear the cylinder leaking in exhaust manifold and at the crank case breather (or oil fill) simultaneously. A couple of squirts of oil will temporarily seal the rings for a couple of minutes and allow you to remove their leakage from from the equation. Now you can rerun the test and find out just how much is leaking in your exhaust valve, etc.

If the valves are leaking too much, you will need to pull the heads. If you have leaky rings, you may not gain as much power as you might think by re-ringing the motor. But excessive leakage past an exhaust valve will eventually burn up the valve and seat. And too much leakage past an intake valve will make that motor run rough.

Anyway, FSTJACK is correct.

 

[71dusterjon]

has anyone else had a problem with a pcv breaking down and letting pressure back into the crankcase?

Is there any reason why my truck should run different if had both sides of the motor vent into the exhaust versus having one being ported vacuum and the other being manifold vacuum?

 

[JTS VENOM PERFORMANCE]

I think it's your muffler bearings bbwwaahaha

 

[DevilDawg3097]

This may sound stupid, but I had the same thing you are having and the only reason I did not think of it because I put new ones on. Your plug wires are shot and might be arcing out on the headers or exhaust. Especially if you reused your plug wires(pulling them off after they pretty much dry rott but can't see any cracks). Heat build up is a big problem for the plug wires under our hood. start the motor in the complete dark if it is you will see a good show. Again just a thought. And it wont throw codes. 6 out of ten wires were bad on mine.

 

[71dusterjon]

Are you refering to my knocking sound? if so, i never would have thought that. I will try that tomorrow. The plug wires are oem. how often are you supposed to change plug wires?

 

[DevilDawg3097]

if they are oem and you have more then 10k miles then you need to change them. And yup the noise was very frustrating it would go from a miss to knock to a header leak( had sean pullin his hair out and thinking Im retarded:joyman: it hesitate at start up run fine until the wires started heating up and the game was on:dontknow: noises I never new arching could make but you may be suprised. Also only reason I had the lights off was cause the bulb popped in the garage when i opened the hood. So I go lucky Then it was like the 4th of july under the hood:dontknow: But just a thought.

 

[71dusterjon]

i'm baffled. Well these wires definitely have 37,000 miles on them.

I guess that would make sense that it could be the wires since i did take them off of the plugs ( i left them attached to coils)

 

[Prof]

Matt raises a possible issue. I also burned one plug wire when it came out of the loom four or five years ago...that was enough to create a terrible problem...in my opinion you change plug wires anytime the intake comes off, because it is a bitch to have to do it with the intake on, but has been done.

 

[71dusterjon]

I did a leak down test to confirm my that the rings have excessive blow by plus use scope to also confirm. the dipstick tube sounded like a wind tunnel and the oil gallies had air coming through them.

I also pulled each wire while truck was running and i have 6 of the 10 cylinders without spark. I'll be upgrading the coils and plug wires

I need to know what are the correct spark plugs for my application. I put in the iridiums but i didn't know they are hotter than what i need. So i need to replace those with the correct ones.

Ran the motor with valve covers off to see how the valves were working and every lifter was pumped up within a minute.

I want to try to figure out my knock before i tear apart the motor for the rings.

 

[bigike]

pulling the wires you didn't notice a difference in the knock? If not then it's not in your rotating assembly.

Again if all you did was pull they headers and put the intake on, and change spark plugs you need to work in reverse to find the problem..

Your compression problem has been there for a while.

did you run the stethiscope over the engine?

When you installed the mallary CC evac system did you put it in the right place? before or after the cats..

Also if your CC was pressurized then you would be leaking oil. Are you leaking oil?

 

[71dusterjon]

pulling the wires you didn't notice a difference in the knock? If not then it's not in your rotating assembly.

Again if all you did was pull they headers and put the intake on, and change spark plugs you need to work in reverse to find the problem..

Your compression problem has been there for a while.

did you run the stethiscope over the engine?

When you installed the mallary CC evac system did you put it in the right place? before or after the cats..

Also if your CC was pressurized then you would be leaking oil. Are you leaking oil?

I pulled one wire off at a time then put it back on and i did NOT hear a difference in the knock.

I'm waiting for tony to give me a price on coils. I'll be changing the wires and also the plugs to see how it runs with new spark.

I only ran the stethiscope over the engine when we were doing a leak down test to see where the air was coming from. Do you want me to run it over the engine when its running?

I put it in at the collector for the headers 1) because thats the only room i have to mount them correctly 2) in the diagram and directions it said to mount it there.

Again i dont know how much pressure the CC was under but NO i'm not leaking oil nor never have. Maybe each time i ran it i was shutting the motor off before it could really build pressure and blow something. I've only ran the motor only a few minutes each time i've had it running.

 

[JTS VENOM PERFORMANCE]

I'll get it all to ya tommorrow, pricing up all you asked for buddy, but by the time I got a chance to call it was at there time, so I should have it in the morning all ya need

 

[Vman455]

in my opinion you change plug wires anytime the intake comes off, because it is a bitch to have to do it with the intake on, but has been done.

By me! Yeah, I'll keep saying it.

OK, back to the constructive discussion.

 

[71dusterjon]

well the ignition is not my problem. I'm going to have to sell the truck. Oil pressure was about 25lbs, which i obviously wasn't paying that close attention too before hand.

I having the oil tested to see what material is in so i can determine what needs to be replaced besides the rings.

Any reason why the new oil cooler lines would cause oil pressure to be so low? Truck does have correct amount of oil.

 

[Prof]

If the ring lands have gone away (which has happened to lots of us, but mostly under forced induction) that would cause the blow-by and the loss of oil pressure.

My bet would be that you have the ring land issue and that a chunk of the land got in the wrong place and you may well have a spun main or a bent rod.

Don't panic...get some estimates on a re-build...you can find builders who will do the work in a conservative manner and you might be surprised how quickly you can be back up and running...it may even be affordable.

Call Tony before you do anything rash...talk to him about the options...please!!!

Here is what to look for when you pull the pistons:

 

[ZCx]

ya got access to a bore scope?????

 

[bigike]

Jon before you write off the engine please replace the oil pressure sending unit. 15$

I had 25 psi for a long time then nothing at idle... it was the sending unit. Good Luck.

 

[71dusterjon]

i dont have a bore scope but i can ask around. I can try the pressure unit but i think prof is right. Your picture didn't show up.

I dont want to sink tons of money into it. I'm afraid that if i pull i'll have to spend more than what i would like. Piston(s) could be bad, definitely need new rings, possibly bearings, maybe a rod, and if the crank is bad maybe that too.

I'll see if i get any bites on the truck. if not i'll wait till the summer time when i have more money and time to fix it.

 

[Tooloe]

my valve train sounds the same??? i listen to the video again and it's not that bad.. i think something is taping on your pistons