Well I believe the valves crashed on my fully built 2.4. About a year ago or so I put the MD ld9 lightened crank pulley on and all was good, nice looking piece and all for the money. For background I run the GM SC with the 2.6 incher, meth, HPT, everything you can think of I have pretty much. Anyways the crank pulley was installed by me and I am not new to engines, and I did not use junk tools, I work on cars all day everyday. Everything was installed liked it should be with a Snap On impact gun so the bolt was tight. The car burened up a belt which was weird since it never had in over 12K miles. I put a new belt on and it did the same thing with 50 miles, upon inspection there was a little play in the pulley so I checked the 27mm bolt to make sure everything was tight and right which it was. I burned up this belt on the side of the road and it was my last one so I had to get to a parts store for fear I would loose it before I could pull the pulley off and inspect it. So I drove about 3 miles to the parts store and the car died and I had no clue what happened. Upon inspection the pulley was OFF! the bolt came out and the pulley fell right off. The pulley then was able to be pushed on and off the crank, which is not good because it should be pressed on. Upon closer inspection the groove for the keyway in the pulley was not accurate at all causing it to have play in it. This play I am asuming loosened the bolt causing the pulley to come off and wear down allowing it to fall off. Now the killer, with that pulley off the keyway is fully exposed and guess what holds the key in there which also connects the timing chain to the crank spinning the cams. the crank pulley, thus the bottom end was spinning with the cams not causing it to die and likely to crash the valves.
I then saw that the key was gone and had it towed home, I assumed the timing would just be off. I then pulled the timing chain cover and it was indeed off. I put in a new key and crank pulley. I re did all the timing components assuring they were all in working order, they are about 10K old. I put the car all back together and checked the plugs all was well. I then went to fire it up, it fired but was not right at all. I then did a compression check here is how it read, I dont know how they number the 2.4 so I will show it like this
tranny - 150 - 0 - 149 - 0 - Timing Chain
Not sure if that is considered the 1,3 cyls, or the 2,4, either way no compression. I am to the understanding that when the crank pulley came off it cause the key way to disenguage not spinning my cams, the motor then continued to run for a few RPMs doing enough damage to the valves.
The car is now coming off the road because I have to many other projects, I used this car as a daily and it must be reliable. With this set back it may cause me to park the car. The car ran absolutely flawless before this as far as reliability goes and I just dont have the time or the energy to get the car done. I am going to the chevy dealer this weekend to buy a Colorado ZQ8 with the 0 financing. Custom parts can contribute to big problems, not saying it is anyones fault, custom cars custom problems.
Let me know what going on, anyone seen problems such as this? I wont be able to F with it until fall, but anyone seen similar symptoms.
http://members.cardomain.com/vertz24 1998 Z24 Convertible
2.3-2.4 HO ADAPTER FLANGES 65$ shipped, Check GP Forum!
Well, Im not sure but Ive made post of my timing jumping and bent 11 of my valves and to this day I dont know why it happend.. I also have this pulley and Im not really sure that I could blame this pulley..
However, it is easy to take on and off.. I do have to hit it with a rubber mallet to get it on and I do have to use a pulley puller to get it off.. Soooo, not sure..
I can't say the reason for my timing to jump is because of my pulley or not.. Interesting though.
~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD
AUTOMATIC!!
328 HP
306 TQ
i wouldnt outwardly blame the pulley for the 'crash' of the valves, you dont KNOW for a fact thats what caused it.
honestly, i cant see how that would even effect the timing, it goes on the end of the crank, the crank has a seperate toothed gear for the timing chain near by, thats just weird.
i cant say from experience as i have not used mike's pulley before, i have however installed the RSM ud and the RSM stock sized crank pulleys before and they had some play to them, u didnt need to press them on OR hit them with a mallet of any kind to get them on, they went on nice n snug though.
the STOCK sized one i put on an 01 grand am, its seen probly 10,000 miles since the install and its fine. the UNDERDRIVE went on my car and has only seen about 1000 miles and its fine, allbeit far to early to tell, but the car runs great and has no issues.
The crank assembly involves the crank gear that the cams are synced with via a timing chain. The gear is held on and spun by a small metal shim (or key). The timing cover has a gasket that pushes up against that assembly and held there by the crank pulley. So, if the crank pulley were to fly off, especially at like 3000+ RPMs... I could see that causing the key to become dislodged from the crank, untiming the cams, forcing them to smash the valves into the pistons. However...
Your 1 and 3 cylinders are the only ones affected by whatever happened. Which I would suspect as fried pistons or rings seeing as those two cylinders move the pistons/rods in unison. The cams do not move in unison: Each lobe is separated by 90° (meaning the 1 & 3 are separated by 180°). So, my diagnosis....I don't know what to tell you... sorry.
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"Youth in Asia"...I don't see anything wrong with that.
I really dont see how the crank pulley can cause this either.If the crank pulley falls off or whatever,the only thing that will happen is the alternator wont charge,because its not being turned.I have started my car plenty of times with no belt on it.Nothing ever happened.The only way i see the valves crashing is from the timing chain breaking or the chain skipping a couple of teeth on the sprockets.Maybe you had a bad timing chain tensioner?The cams and crank are all in sinc with the timing chain.If the crank pulley falls off,the crank will still turn with the cams via the timing chain.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
Hold on let me edit that.
So your saying the alignment key came out completely?If thats the case,yeah that will def do that to your valves because that keyway drives the timing chain sprocket also.I still dont see how the crank pulley will make the bolt come loose.Did you tourque the bolt down when you tightened it?I never tourque it either,i just drive it with the impact gun.I hope u figure out what caused it.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
I have seen this same exact thing happen to a 2.4 with a ebay pulley. I do not blame the pulley. I was one of the opnes who last installed that pulley. Still same thing, bolt came out, pulley came off key came out and crashed ever valve in the head. The pulley can't cause the bolt to come out. Just can't. You could have messed up installed it. I have also seen pulley's (2.3 Ho pulley) that slide on without being pressed on.
Also jumping timing, and the key way coming out is 2 different things.
Edited 1 time(s). Last edited Friday, July 06, 2007 4:13 PM
FU Tuning
your really supposed to use locktite on the bolt , and tq
granted the cast iron crank pullies we do get away with just zinging them on with the impact
its been awhile since ive looked , but i thought there was 2 keys 1 for the timing gear and 1 for the balancer pulley
My guess would be that the pulley was not torqued down to the proper torque rating, and was never checked a few days later to ensure it was properly tightened on the crank. The pulleys are a "PRESS fit" and are reamed from the manufacture. The pulley inner diameter is pretty much dead on all the pulleys, because it is reamed from the manufacturer. I measured all the pulleys when i received them before I shipped them out, and all dimensions were fine.
Also why didn't you contact me or say anything if the pulley was loose, or you thought there was a problem. I would be more than willing to help you out or try and help to solve your problem. Why is this post the first time I heard of anything?????????????????
The pulley is a press fit. Mastin and others posted about it being a press fit. It should be.
Chris the pulley should have no play, and even if it did, when the pulley bolt was snugged down there is no possible way the pulley should have ANY play.
I believe it is very un-far that you blamed my pulley for bent valves, when you do not know that it is the direct reason. If you want...you could send me the pulley so i can check the dimensions, but I'm sure it was fine when it was shipped to you.....and everyone else, also.
Also the belt issue. I have heard of NO-one having this problem. At least not from the other 33 people...including myself. I beat the "@!#$" out of my car for months before I even ran my group purchase.
I just do not see how my pulley could
MAKE the bolt come loose.....it just doesn't make sense.
David, you should need a mallet and pulley puller just like the OEM pulley.
Added
Also like the alternator pulleys. Some people had a problem with a few after market alternators. They sent them back to me, and I fixed said problem. Why wouldn't I do the same for you, but i need to know of a problem before I can help fix the problem...........if there was a problem.
Also isn't this the same motor you have had hell with since you installed it. I remember reading lots of posts on this or that not going right with the motor, correct? I'm not trying to shift blame. I do not think there should be ANY blame. I justed can not see the pulley causing the crank bolt to come loose...if it was properly installed. I am sorry that you believe my pulley broke your motor.....I just can not see it being my crank pulleys' fault.
Edited 1 time(s). Last edited Saturday, July 07, 2007 10:04 AM
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
I never said it was your fault, it is no ones fault and a freak accident. The motor is cooked, said and done blame has not been put on anything. I actually complimented your product in my post, lol.
Anyways, I know it should be pressed fit and thats how it was when it was originally installed. I did not have these issues with the pulley untill the motor started throwing belts. I also did check it days after I installed it, I am not new to this I always check my work.
As for my motor, the car always ran like a top, it was just slower than others since I lowered the compression, other than that you could drive it around the country no problems. I drove it every day 60 miles to college and back never had a problem.
What I understand happened and it make sense when you see it in person is that the crank pulley for some reason was not pressed on anymore, perhaps there was a problem with the metal compressing? Long shot I know, but it does not matter the pulley should be pressed but fell right off. Also the key way was significantly wider than it should be, perhaps from not be pressed it moved and had play causing rubbing. Since it was not pressed fit for whatever reason it would cause the bolt to possibly come loose due to constantly rubbing.
I am just saying it may have contributed or caused the bolt to unscrew and essentially have the pulley come off. Also since the pulley should be pressed on I also have thought maybe the machining was off by a few thousanths causing a decent fit when installed then over time wearing down to allow it to come off. Long story short if the pulley did not come off and it actually was a pressed fit like the stocker this would not have happened. Aftermarket parts are not as good as stockers.
As for why i never contacted you, once I found it was bad it was too late. I did not know the pulley was messed up until it fell off and the valves crashed, so a new one at this point wont help. I am just going to scrap the thing and throw it out since I would never want this to happen to anyone. I am just putting it up there because I dont know what to expect when I tear it apart. I am looking for others with other simptoms.
End of the day its over, motor is shot, thousands of dollars wasted. It does not help to get mad, just keep and eye on the pulleys so they stay on good and tight. I know it is hard to explain but if you saw the motor in person it makes perfect sense, intiernet is hard to explain espicially without pics.
Oh well I bought an 06 SS SC cobalt, cavy is parked for a while.
Chris
http://members.cardomain.com/vertz24 1998 Z24 Convertible
2.3-2.4 HO ADAPTER FLANGES 65$ shipped, Check GP Forum!
[quote=97trd(???™)]your really supposed to use locktite on the bolt
x2
[quote=97trd(???™)]
its been awhile since ive looked , but i thought there was 2 keys 1 for the timing gear and 1 for the balancer pulley
just one key
I have a Z in my driveway right now, that you can remove the crank bolt and pull the pulley off by hand, and slide it back on. Its been on the car for 25-30k miles, and has never thrown a belt. The bolt was torqued with a torque wrench though. It usually takes a 1/2" ratchet and a cheater bar to brake it loose though.
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
Quote:
I also did check it days after I installed it, I am not new to this I always check my work.
I have never done this. also have never used locktite on the crank bolt either. I also have never used a torque wrench on that bolt.
Quote:
Also the key way was significantly wider than it should be, perhaps from not be pressed it moved and had play causing rubbing
I would think if the key was wider than normal it wold have stock into the pulley, so when the bolt came out and the pulley came out it pulled the key with it. Even if the pulley was tight with no bolt on it and the force created when the motor is turning I can see how it came off.
FU Tuning
Quote:
I am just saying it may have contributed or caused the bolt to unscrew and essentially have the pulley come off. Also since the pulley should be pressed on I also have thought maybe the machining was off by a few thousanths causing a decent fit when installed then over time wearing down to allow it to come off. Long story short if the pulley did not come off and it actually was a pressed fit like the stocker this would not have happened. Aftermarket parts are not as good as stockers.
There is no wear in between the crank, key, and pulley. It should act as one piece after the bolt is snugged down. I just can not see how the pulley inner diameter changed. The aluminum might relax a little over heating and cooling cycles, but not enough to slide of the shaft easy, unless under high RPMs and not being held down by the bolt.
Any pulley stock or not would come out with a loose bolt, and intern the key fall out as well.
Also I would still like to see the pulley to check the dimensions, I still do not think the pulley is bad...can I see it? Can you mail it to me... I'll even pay shipping.
Chris I must of took it the wrong way. "MD LD9 pulley, Contributed to Crashed......" But I got defensive, and well I felt like you were blaming, buy anyway. I'm sorry you feel the way you do, and we both have said our sides. I hope you the best with the new car, and the cav.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Haven't you, in general, had alot of problems with your car?
I was always taught that most of the time, if it was something that a human had messed with, its human error that has led to the problem......
But I'm just throwing it out there, as a "tec" you should know this, along with the use of lock-tight on the bolt.
But now I'm speculating.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
