Curious as to the outcome for sure.
CK5
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383 Stroker noise - Name that tune
- Thread starter Lunatic
- Start date
I agree with the vacuum leak theory...
Possibly the brake booster,I had one leak at the master cylinder once!--there was a bolt hole in the casting that the proportioning valve bolted too that had vacuum suction when the diaphram in the booster was failing...make sure the hose and check valve are intact to the booster and engine vacuum port..
OR, maybe the intake isn't sealed well at the rear where the rubber seals went (the ones GM says to toss and use RTV instead!)--I've heard a small block that had that "hissing snake" noise at shut down before,and it was vacuum leaking there--a quick way to test that would be to pinch off the hose to the PCV valve and run it with it "blocked" ,that wont let any vacuum build up in the crank case..
I've had engines that lost a lot of oil pressure once they warmed up fully,and just changing to a different brand and weight of oil "cured" that...the 350 in my 72 K5 would drop to 10 psi at idle when I used 10W-30 Amalie oil in it--changed it back to the Castrol 20W-50 I used previously,and it never went below 35 psi at idle...some oils thin out a lot more than others once it heats up..
Stomis
Professional Amateur
Idk why loosing pressure when warm is a discussion here? All motors loose an amount of oil pressure when warmed. Its a side effect of the oil becoming thinner. Its consistency across RPMs that should be a concern.
Looking at the first post again,I agree,60 psi cold dropping to 40 psi is not anything at all to be concerned about...thats "perfect" in my book!..
I've had several chevy's that had the oil pressure drop to as low as 7-10 psi at idle,and I never heard a lifter click or bearing rap in any of them,other than perhaps a quick "woodpecker" type rattle when you restarted them hot ,that lasted only 2 seconds till the pump built up pressure..
I've had several chevy's that had the oil pressure drop to as low as 7-10 psi at idle,and I never heard a lifter click or bearing rap in any of them,other than perhaps a quick "woodpecker" type rattle when you restarted them hot ,that lasted only 2 seconds till the pump built up pressure..
Lunatic
1/2 ton status
Not fixed yet..............BUT........
Well, firstly - Thank you everyone for the replies and suggestions - This just took a leap forward (explained below).
black dawg, I went and checked the EGR plate - It was tight, but I tweaked a further chirp out of the hardware.
cyclic, I eliminated the booster completely tonight - It has been disconnected at the carb and plugged until this is resolved.
Fordum, you dont bash man - You educate ! Theres a difference. I just got schooled on synthetic oil. Thank you sir. This engine was dyno'd prior to my receipt, with high grade non-syn 15w40 oil. So initial break-in really occured before it was even signed for. I'll just say "break-in was started" prior to receipt. My plan was 1st 500 with synthetic for lubrication, then going to conventional. Thanks for the info, I didn't know and am now informed. I'll be switching to my old brand oil - Castrol GTX 15w40 and using an zinc additive.
The front end was painfully inspected for "anything" early on - The balancer is clear. And the booster has now been eliminated as well.
CGT80, I have a full roller valvetrain - I'll look for your suggested ZDDPlus. I'm not a synthetic man either - I just "assumed" better lubrication, which is apparently true, and not so desired with a fresh build. My oil is mostly 3 months - Cause the Jimmy doesnt see 3k first.
Stomis, keep reading.
blazer74, the noise does continue after shutdown...... I think I'll say, "has its finale" - The noise doesn't pause for the squeal, it carries on to it, if that makes sense.
diesel4me, oil presssure isnt a concern, as you finally noted - It was just a reference, another detail I thought may be helpful. Thanks for the reply !
---
So, thats everyone I think - Sorry if I missed an answer or two.
Here's what I found tonight.
I found the source, or as close as I can come to it without breaking the engine open. As I had hoped, touching the rear main seal housing presented the resonation of the squeal, without doubt. I told the wifey to stand outside the driver door, and wait for me to touch her leg - The signal to shut the engine down. I got in place, stethoscope on point, listening to the squeal, and reached for contact - Shut down followed, and so did the elk mating call.
So, from here, I am still on the single issue track, and 99% certain of the oil pump shaft spinning being the squeal, and the relief valve being the elk mating call.
I'm just smiling because I have a target now and can move forward.
I'll be calling the builder tomorrow, to see how he wants to proceed. I have no issue burning the labor costs (doing the work myself), and losing the time (myself), as long he replaces the part and it doesnt effect the warranty - A decision only he will make.
Thanks again, brotherhood. This will be updated when definitively corrected.
Any other ideas on something else it could possibly be ??
Troy B
Ft Hood, TX
Well, firstly - Thank you everyone for the replies and suggestions - This just took a leap forward (explained below).
black dawg, I went and checked the EGR plate - It was tight, but I tweaked a further chirp out of the hardware.
cyclic, I eliminated the booster completely tonight - It has been disconnected at the carb and plugged until this is resolved.
Fordum, you dont bash man - You educate ! Theres a difference. I just got schooled on synthetic oil. Thank you sir. This engine was dyno'd prior to my receipt, with high grade non-syn 15w40 oil. So initial break-in really occured before it was even signed for. I'll just say "break-in was started" prior to receipt. My plan was 1st 500 with synthetic for lubrication, then going to conventional. Thanks for the info, I didn't know and am now informed. I'll be switching to my old brand oil - Castrol GTX 15w40 and using an zinc additive.
The front end was painfully inspected for "anything" early on - The balancer is clear. And the booster has now been eliminated as well.
CGT80, I have a full roller valvetrain - I'll look for your suggested ZDDPlus. I'm not a synthetic man either - I just "assumed" better lubrication, which is apparently true, and not so desired with a fresh build. My oil is mostly 3 months - Cause the Jimmy doesnt see 3k first.
Stomis, keep reading.
blazer74, the noise does continue after shutdown...... I think I'll say, "has its finale" - The noise doesn't pause for the squeal, it carries on to it, if that makes sense.
diesel4me, oil presssure isnt a concern, as you finally noted - It was just a reference, another detail I thought may be helpful. Thanks for the reply !
---
So, thats everyone I think - Sorry if I missed an answer or two.
Here's what I found tonight.
I found the source, or as close as I can come to it without breaking the engine open. As I had hoped, touching the rear main seal housing presented the resonation of the squeal, without doubt. I told the wifey to stand outside the driver door, and wait for me to touch her leg - The signal to shut the engine down. I got in place, stethoscope on point, listening to the squeal, and reached for contact - Shut down followed, and so did the elk mating call.
So, from here, I am still on the single issue track, and 99% certain of the oil pump shaft spinning being the squeal, and the relief valve being the elk mating call.
I'm just smiling because I have a target now and can move forward.
I'll be calling the builder tomorrow, to see how he wants to proceed. I have no issue burning the labor costs (doing the work myself), and losing the time (myself), as long he replaces the part and it doesnt effect the warranty - A decision only he will make.
Thanks again, brotherhood. This will be updated when definitively corrected.
Any other ideas on something else it could possibly be ??
Troy B
Ft Hood, TX
Stomis
Professional Amateur
Glad you got somewhere!
I noticed the pcv was in the drivers side valve cover, but didn't see a vent in the passenger side. Could you be building too much vacuum and be whistling through one of the gaskets or seals? You could pull the oil filler cap to check.
Pull pcv valve out of valve cover, shut off engine, see if noise changes. We have run into this several times over the years when a customer thought they had a converter noise. It is either a collapsing vacuum line or the intake manifold end seal.
my thoughts too. if no vent could it be sucking air at the rear seal
I'm still on board with the vac leak theory, just not convinced on the oil pump. Noise continues after shut down I think is the clue. IMHO
Lunatic
1/2 ton status
For those which said anything about vacuum, you were closer than I was, even though I was 1/4" away from the issue and didn't see the trees for the forest.
ChrisPerry, Greg Ducato and frankin5 nailed it.
This problem is resolved.
So, short version - The engine wasn't breathing properly. Because I didn't have a breather on either valve cover, it was basically a sealed engine, with a vacuum that had to inhale from the weakest point - The one-drop-leak-rear main oil seal, to be precise.
The solid squeal was from air passing the sealing surface at the crank, which, because it was spinning, kept the seal seated and "rigid" - So the squealing was actually whistling. When the engine was shut down, the seal rubber basically flapped/vibrated as the vacuum pushed past it, producing the elk mating call.
I did call the builder this morning, and he suggested exactly what ChrisPerry and Greg Ducato responded with before moving forward. I came home, popped the pcv and oil fill cap, and fired it up.
Noise was gone. I put the pcv back in, still no noise. I then put the oil fill cap back in - And within 5 seconds, the initial noise returned. When I pulled the oil fill cap back off, the action produced a loud gasp from the hole I just opened, like popping the top on a carbonated drink can.
So, I went to my box of goodies, grabbed a breather and it is now in place of the oil cap.
Insanely-stupid-simple fix, as someone previously mentioned.
Still learning on a daily basis.
I appreciate everyone's involvement and suggestions with this topic - I can always count on the brotherhood to offer support
This problem is solved - Thanks brotherhood !
Troy B
Ft Hood, TX
ChrisPerry, Greg Ducato and frankin5 nailed it.
This problem is resolved.
So, short version - The engine wasn't breathing properly. Because I didn't have a breather on either valve cover, it was basically a sealed engine, with a vacuum that had to inhale from the weakest point - The one-drop-leak-rear main oil seal, to be precise.
The solid squeal was from air passing the sealing surface at the crank, which, because it was spinning, kept the seal seated and "rigid" - So the squealing was actually whistling. When the engine was shut down, the seal rubber basically flapped/vibrated as the vacuum pushed past it, producing the elk mating call.
I did call the builder this morning, and he suggested exactly what ChrisPerry and Greg Ducato responded with before moving forward. I came home, popped the pcv and oil fill cap, and fired it up.
Noise was gone. I put the pcv back in, still no noise. I then put the oil fill cap back in - And within 5 seconds, the initial noise returned. When I pulled the oil fill cap back off, the action produced a loud gasp from the hole I just opened, like popping the top on a carbonated drink can.
So, I went to my box of goodies, grabbed a breather and it is now in place of the oil cap.
Insanely-stupid-simple fix, as someone previously mentioned.
Still learning on a daily basis.
I appreciate everyone's involvement and suggestions with this topic - I can always count on the brotherhood to offer support
This problem is solved - Thanks brotherhood !
Troy B
Ft Hood, TX
Lunatic
1/2 ton status
I'm pretty sure the rear main wont be leaking a drop of oil on the seal housing now too....
This was just one thing on my plate. Now that the Jimmy is "up" again, it can be attached to my trailer and tow enough wood for a 20x20 deck
.
One win for me - One win for the wife. Funny, all she did was turn the Jimmy off a few times.
Troy B
Ft Hood, TX
This was just one thing on my plate. Now that the Jimmy is "up" again, it can be attached to my trailer and tow enough wood for a 20x20 deck
.One win for me - One win for the wife. Funny, all she did was turn the Jimmy off a few times.
Troy B
Ft Hood, TX
Also never do the mistake to put two breathers or your oil would get dirty in no time, always run your motor with a breather on one side and good PCV valve on the other.
I noted on the video that the vacuum port was not hooked on the distributor to the carb or intake but plugged?
I noted on the video that the vacuum port was not hooked on the distributor to the carb or intake but plugged?
I'll have to put this one in the memory banks.
Stomis
Professional Amateur
Congratulations. First person Ive ever heard of having a flatulent motor lol.
Lunatic
1/2 ton status
Jean, the dizzy has an electronic advance and was actually dyno'd w/o vac.
I still haven't ran it with vac but, in truth, was about to start looking into the difference a vac connection would make when the engine started singing a crazy tune.
Now, I will most likely go back to checking it out - It drives me nuts seeing the dizzy capped off.
Troy B
Ft Hood, TX
I still haven't ran it with vac but, in truth, was about to start looking into the difference a vac connection would make when the engine started singing a crazy tune.
Now, I will most likely go back to checking it out - It drives me nuts seeing the dizzy capped off.
Troy B
Ft Hood, TX
CGT80
1/2 ton status
What is the electronic advance? What controls it and what sends a signal for the advance? I see you are running a carb, is it at all computer controlled? I have heard of MSD dizzy's that have an electronic control for the engine speed based advance curve, otherwise known as (mechanical advance). They use little dip switches to set the curve you want, rather than weights and springs. My MSD HEI Pro Billet is from 2003 and was before that came out so it still has the springs and weights. The vac can will advance the timing with high engine vacuum. They are two separate things. Vac advance can be run from manifold vacuum or ported vacuum depending on whether or not you want advance at an idle. I use ported so no advance at idle. At higher rpm, I will have mechanical advance. Under only light load/throttle, it will also have additional vac advance and that should help fuel economy. At the same rpm with heavy throttle or load, the vacuum is lost and the vac advance is not there, that way it doesn't ping.
You may have a computer controlled setup that I am not aware of, or you may have the two types of timing control confused.
