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gtp s/c rotor swap HELP

I haven't seen anything odd in the fluids as of yet... other than my oil looking VERY black when my DIC says I still have like 80% left... (castrol gtx 10w30)
 


Cyko said:
I haven't seen anything odd in the fluids as of yet... other than my oil looking VERY black when my DIC says I still have like 80% left... (castrol gtx 10w30)
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That's the oil doing its job and absorbing carbon. Just because oil is black doesn't mean it's bad.
 
Oh I know, and it's a different oil than I usually use, no biggie or anything, just saying that's the ONLY thing I've noticed about the fluids
 
Goose the throttle with a hand on the oil pan huh? :th_scratchhead:

Ooooooooooook.

If he felt a thump like a thrown rod, than the noise you would be hearing at idle would be so freaking loud all the time you would not want to ever start your car up.

I seriously doubt you threw a rod.

Check the idler pulleys, and the the rest of the pulleys. for starters.

Here is a question for you, what was the last thing you did to your motor before this happened? Mod wise or even service under the hood.

What ever it was...start with that for starters, you might find something you missed.

~F~
 
GR8racingfool said:
Here is a question for you, what was the last thing you did to your motor before this happened? Mod wise or even service under the hood.

What ever it was...start with that for starters, you might find something you missed.

~F~
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As far as Service or mods, the only things done to the car were a CAI and an oil change, as well as a new S/C snout/coupler.

I will say this, when the noise started, I had just gotten a call at work from the wife, telling me that my 7 month old son had stopped breathing (he's fine btw), so naturally I ran to the car and immediately got it as fast as I could, as QUICK as I could. The first time I slowed down enough to hear the noise, is when I actually noticed it, and it was NOT happening when I drove to work that morning... just a little more insight I guess... I think I'm dropping it off at a friend's Uncle's shop (cheap work, it's nice) tomorrow before I fly out to Florida with the family, so I won't even miss 'er. (I'm lying... she's in the driveway but I miss her already 'cause I haven't driven her in like 3 days... it hurts!)
 


Some guy on ebay... I bought/installed it back in February I think, and I've never seemed to have any problems with it.
 
Just for reference....this is what a knocking rod sounds like.
YouTube - 97 KenneBell Cobra - 4 valve suffering rod knock..

There's a trick that comes in extremely handy for finding engine noise.
Get you a dowel rod from wal mart, or a hobby store....sand one end so that it has a bullet shaped tip, and use that to find your noise. You can put it to the side of your head over your ear, not IN your ear, and then cup your hand over that. If the rotors are knocking, you will hear it...if it's somewhere else on the engine, you could find it that way.

I'm not sure if you had taken the main belt off as well...but if you are sure it's coming from the driver's side then it may not be the pulley system. It could be a cracked flexplate.

Cracked Flexplate Video

If this is the case....you're gonna need minor surgery. The engine...or the transmission will have to come out to replace this.
 
GR8racingfool said:
Until now.

~F~
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GR8, still makes the noise without the snout having a belt on it...


Rep, it DOES sound more like the first video, but no where NEAR as bad... the second is just completely different, I can barely hear it from inside the car, unless I'm at a high RPM. I'm currently on vacation on the gulf coast of Florida, but when I get home I'll make a quick video and let you guys hear the issue. I can't figure it out, and now it's just about getting it to a good shop to have someone charge me out the @ss to tell me something small is wrong and they replaced it, as well as 4 other "notquitebrokenbutwillbeinthenext100thousandmiles" parts that I didn't need. We'll see what happens.
 
Mine sounded like that first video when I spun a rod bearing. It started out as barely noticable and only at higher RPMs. Over the next few days it got louder even at idle.
 


Alright SS... IF that were the case and I spun a bearing.... am I still in the same boat financially? Cheaper to get a whole new engine, rather than tear the heads off and pull the block apart to get to/replace that one bearing?
 
if you get a new engine it will probably cost more than a rebuild...if you get a used engibe you never know what it has been through or how long it will last.


a rebuild imho is the best solution if this were the problem....rod bearings,crank bearings,rings,line honing,cyl bore honing and labor at a decent machine shop shouldnt cost more than a used engine with 70000 miles....you do the math lol
 
You can pick up a used L67 for as little as $500-700 depending on the yards near you. Ed Morad sells them too. A engine rebuild would be more than that, from what I've seen.
 
I would look for another engine and do a direct swap if it is internal.

Rebuilds are not as cheap, and not as reliable as a untouched factory bottom end.

It takes a good mechanic and a good machine shop to be able to rebuild one of our 3800 and not have a failure 500 to 10,000 miles later.

If its a broken flex plate, thats easy to see or find, climb under your car, and remove your cover and shine a light up in there and look for cracked, bent, or broken metal pieces. You can replace the flex plate with both the motor and the transmission in the engine bay, you separate the motor from the transmission and sorta push it to the side as far as it can go, there will be enough room to get in between the block and tranny to remove the bolts and the flex plate for the swap. Thats how one guy did it in the pits at the Pontiac Nationals a few years ago. Oh, and you have to use a engine hoist/cherry picker to move, support/hold the motor while your doing this replacement this way. :th_thumbsup-wink:

~F~
 


Thanks for the info guys... you've certainly given me a LOT to look into and a slew of new diagnostic methods. I'm gonna end up taking it to a mechanic friend of mine just to see if he can tell me definitively what's wrong with it, and go from there, but I'll make sure I mention the ideas posted here... God help me...

Thanks again for all the input =)
 
My engine was rebuilt all the way down to replacing the crank, #1 piston and all associated items. It cost me $500 in parts (not sure how much the shop kicked in) and the labor was free. Long ugly story as to why the price was what it was. Anyway, I feel pretty lucky as the rebuild was done about 43K miles ago. As mentioned many rebuilds have not been successful though.

IF you have engine failure then Ed Morad is likely your best bet.
 
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