Ok, heres the situation
Ive got a 97 z24 cavalier with a 99 2.4l engine and its knocking when i get to 2500+ rpms. I have checked for clearance on everything in the engine bay and its all fine. It was throwing a knock sensor code but once i replaced my pcm so i could hook my ks up the code went away.
what ive done so far
-replaced fuel injectors
-replaced sparks
-replaced my 97 ecu with a 99
-passlock relearn
-replaced coil pack thing
what else im thinking
-jumped time?
-one of my lifters is screwy
-tensioner arm on the timing chain
-i should try a compression test too
If i did jump my timing chain wouldnt it knock even at idle? Is there an easy way to check the timing without having to take off the cover and the motor mound and crap.
Is there anything else i should check?
I can upload a clip if needed because ive never really heard an engine knock before but im assuming its a loud knocking noise...
Any help wold be great because im stumpped
Depends on what kind of knock it is, knock as in detonation or rod knock as in maybe a bearing is bad, etc. I think there is a code the ECU will throw if there is excessive knock from detonation, which kind of sounds like a higher pitched pinging popping noise as opposed to a mechanical knock.
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Mitsu TD06-20g |3" Downpipe w/ Cutout | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
BlackEco wrote:Depends on what kind of knock it is, knock as in detonation or rod knock as in maybe a bearing is bad, etc. I think there is a code the ECU will throw if there is excessive knock from detonation, which kind of sounds like a higher pitched pinging popping noise as opposed to a mechanical knock.
it sounds like metal on metal, kinda like im hitting my block with a wrench
if it is rod knock can i check what it might be eaisly? probably not seeing as ill probably have to remove the valve covers and junk.
That sounds like rod knock to me.
If thats the case the motor probably doesn't have much life left in it and will require a rebuild, if you drive it and it is rod knock eventually you will end up with holes in your block.
Mostly likely you will not be able to determine anything by removing the valve cover unless its something other than rod knock like a valve issue.. You need to pull the oil pan and check for metal in the bottom of it.
Once you have the oil pan off you will be able to determine if there is play in the connecting rods, depending on how bad it is you may get by with just some new bearings and having the crank reworked. If thats all to much work and you don't feel like paying a qualified mechanic to deal with it you might be better off just finding a good yard motor with low mileage on it and swapping it in.
Someone with more experience might be able to clue you in more as how to make a determination, but if its really bad it should be evident when you get the pan off.
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Mitsu TD06-20g |3" Downpipe w/ Cutout | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
what about my timing chain? could that cause a knock?
I agree with what blackeco has said so far. It definatly aounds like rod knock to me too. That is very common on higher mileage 2.4s. Your timing chain will not cause knock.
FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!
yep, that would most likely be rod knock... i had the same thing in my 2.4. it sucks but it's common. time to either completely rebuild or scrap it out.
87 Firebird
All stock...........lol.
they by design spin bearings...which is what causes rod knock. bad oiling, usually half quart low can toss one of these motors. Looks like its rebuild time...sorry bud
Randy Beuc wrote:yep, that would most likely be rod knock... i had the same thing in my 2.4. it sucks but it's common. time to either completely rebuild or scrap it out.
Happened to mine twice when I had it. First one went around 100k i believe. Next one went around 80k, but that was only after a few hundred miles that I put on it. Got rid of the car after putting another engine in.
ok, say i get a new engine. i can get one thats all the way up to a 2002 right? does anyone know the estimated cost from the yard?
i just got a 99 ecu so i will have the right hookups for the knock but was there any other changes after 99 that will have to be made to my ecu or anyother wireing stuff?
how long might the swap take if i do it myself?
Darkstars wrote:Wade Jarvis wrote:I agree with what blackeco has said so far. It definatly aounds like rod knock to me too. That is very common on higher mileage 2.4s. Your timing chain will not cause knock.
X2
well i was thinking about it and rods are at the bottom of the engine and i can clearly hear the knock hitting the top of the engine.
sounds alomst like something is hitting the cam covers? could i have a broke ass lifter flapping around?
oh yea i bought the secret cams so ill be putting those in while im in the area.
if i get new lifters what brand might i get? cost?
z24 - CAI - Magnaflow Cat - PaceSetters
--exhaust and unorthadox pulley soon
++++ with my hand over the top of my engine i can feel it hitting there
z24 - CAI - Magnaflow Cat - PaceSetters
--exhaust and unorthadox pulley soon
anyone???
z24 - CAI - Magnaflow Cat - PaceSetters
--exhaust and unorthadox pulley soon
I was going to say check the oil, but you have likely done that by now,
I was running low and I was getting a knock and it sounded like the lifters(maybe, I have no idea) and it just needed more oil.
sounds like you are mechanical so that is likely not it,
but it worked for me
i saw one which when the rod bearing got loose enough, the piston toutched the head on exhaust stroke.... this is what you feel with your hand on valve cover... you most likely have bent valves too.
good luck
AMARZZATA wrote:i saw one which when the rod bearing got loose enough, the piston toutched the head on exhaust stroke.... this is what you feel with your hand on valve cover... you most likely have bent valves too.
good luck
well im hoping its not that because i did a compression test and its all fine there so i know i dont have bent valves.
although i havent driven it much with the noise so maybe its just not bent yet...
z24 - CAI - Magnaflow Cat - PaceSetters
--exhaust and unorthadox pulley soon
corpus Cavy wrote:AMARZZATA wrote:i saw one which when the rod bearing got loose enough, the piston toutched the head on exhaust stroke.... this is what you feel with your hand on valve cover... you most likely have bent valves too.
good luck
well im hoping its not that because i did a compression test and its all fine there so i know i dont have bent valves.
although i havent driven it much with the noise so maybe its just not bent yet...
well it could be the the valves hitting the pistons could be a possiabilty.
corpus Cavy wrote:AMARZZATA wrote:i saw one which when the rod bearing got loose enough, the piston toutched the head on exhaust stroke.... this is what you feel with your hand on valve cover... you most likely have bent valves too.
good luck
well im hoping its not that because i did a compression test and its all fine there so i know i dont have bent valves.
although i havent driven it much with the noise so maybe its just not bent yet...
If valves toutch the piston, you will most likely loose compression. but you might still have a blown conrod bearing... Just not loose enough to do a lot of damage but dont wait for this to hapen, DONT run the engine until you figured out what it is... cuz if it's a rod bearing, each time you start it, the damage will get worse.
