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The engine has developed a knock

14K views 90 replies 12 participants last post by  darkman 
#1 ·
A little back story, because I like to tell a story. Bought a season pass to the drag strip, opening day is today. Fire the beast up this afternoon and I hear a slight knock, most people wouldn't hear it. I blow it off. Get to the track and take a breather and gather my bearings because I'm still getting used to 600+hp, hopping on the freeway I gave it in 3rd gear and I got the "traction engaged" message! Not bragging, but more adrenaline rushes when I drive this car than the 150hp (02 suzuki gsxr 750) sport bike I used to know as the only thing to get my adrenaline going. Ten minutes pass and I get in line, I'm two cars to the tree sitting next to a building with my window down, I hear the knock echoing off said building. I ask the traffic director "Is that me" he replies, "yes". I ask how to leave and he tells me to pull out through an opening, and states "don't blow it up"

We first thought rocker, but it may also be a bearing in the charger. It's not a bad knock, but it got worse from the drive there (20 miles) so I know it is something.
I have yet to tear into an engine, so I don't know much about them. I still have 30+ lbs of oil pressure at idle, I don't think it's that big of a deal, but, like I said, I haven't torn into an engine and have no idea what I'm getting into.

I know my description isn't much to go by, here is a video I took earlier today (before I left for the track). You probably won't hear the knock (drivers side is where it sounds like it's coming from) but I'm trying to give as much info as I can.

http://www.youtube.com/watch?v=7k-eyBRWH2c

I plan to get another video when I take the stethoscope to it to hopefully find out where it's coming from. I don't want to fire it up if I don't have too.

What I know about the heads is:
Ported and polished by BES engines
Patriot Gold Dual springs and Ti retainers
Comp cams 7.450 pushrods with Yella Terra rockers

I will ask the previous owner if he can find out more about who did the work (the guy he bought it from had the work done).

For those who want to help me figure this out, but don't know the car:

http://www.cadillacforums.com/forums/2004-2007-cadillac-cts-v-general/284959-i-bought-one.html
 
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#36 · (Edited)
what city was the car tuned in, and what city is the car in now? (I'm curious about the altitude difference)

...just, assuming the car is in the same running condition as when you picked it up, and no one's integrity is in question (nor is the integrity of the car).

easily ruled out if there was a gain in altitude, or no change. (no harm in asking, right? at the worst I'm wrong, and I'm ok with that).


robojesus: the subs comment, also the first time I knew of you. ...so I assumed robojesus was a troll account, and that you were game.
 
#40 · (Edited)
welp, looks like it's not the altitude thing, and I don't have to quit the internet

this thread is a LOT of fun. I think we should all take a dance break.

yesthankyou robojesus, I am now aware that you are dead serial, and I will not disturb you henceforthwith. promise, girl scout's honor. (but in my defense, I don't think I'm a lot dumber than you thought that I think that I thought I was once.)

amen.
 
#46 ·
She's back together, starts like it should, not hard and slow like it did. Lifter was collapsed 3/8 of an inch. Going to move the iat sensor to the manifold. And add a place to add coolant to the intercooler. I don't know how they got any in there, or if there is any in there, just a nipple to bleed if off... also have to find out why it's only making 5.5 lbs of Boost. Guy working on it tells me it should be making 10+ lbs judging by the pulley sizes. Maybe the 8:1 comp ratio? And then a dyno tune.. she'll be back at the track soon!
 
#47 ·
I'm only making about 5.5 psi boost and even then that's only at about 6k RPM and above.

Car description says you're running an underdrive pulley. If that's on the crank, then that could be a reason you're not getting more boost.

What jackshaft pulley are you running?
 
#57 ·
IAT has been moved to the intake manifold and a tee has been added to the intercooler line (nearly a gallon of coolant was added, that can't be good). He told me that the Meth wasn't working. We looked a little closer and noticed that the control box was turned off. We turned it on and pushed the test button, the test/working light turned on. He asked me to place my hand by the injector while he pushed the test button to see if I could feel anything, I didn't. Is the test button supposed to spray when pressed? I understand that's all about how it was installed, but what is most common? The kit is Alky. I have the manual and it tells me that it is set to spray at 4lbs of boost. I have seen the test/working light come on when getting on it. I'm assuming it works fine, but am unsure. He tells me it was one of his employees that was working on it, and he wasn't around to ask.
 
#58 ·
Meth is working, a vacuum line fell off...
He took it for a spin and told me that it was only running 3lbs of boost and felt weak. That didn't sound right to me. He got back to me later and said that it had belt slip and it was because the guy that put the belt back on routed it wrong, I told him that he is the only one to touch it now lol. He states that it's back up to around 5lbs, but not quite "holy ****" I told him to make it holy **** lol. He is looking into the pulleys on the back of the motor.
 
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