98 chevy k1500 4×4 5.7ltr vortec v8 HELP
November 22nd, 2020, 12:15 PM
#11
CF Veteran
Ok, so obviously there is some clarification needed....here goes...
When I first bought the truck it had a slight overheating issue...I replaced the thermostat,(which there wasnt one), the radiator cap, flushed the system 2x, did an oil change, and was just about to do my front suspension when one day I was getting air, started the engine and grind grind bang, there goes the radiator fluid!! The freeze plugs at the bottom of the block blew, my manifold cover was missing unbenounced to me, so in turn they bent the flywheel...I NEVER HAD ANY STEAM, SMOKE, NO MIXTURES OF ANY KIND, HELL IT NEVER FULLY OVER HEATED!! SO IM ASKING WITH THE COMPRESSION TEST ON ALL 8 CYLINDERS COMING BACK AT 125PSI EACH, DO I HAVE A BLOWN ENGINE?? MY HONEST OPINION, NO I DONT...ALL 8 SPARK PLUGS WERE CHARCOAL BLACK...NO CRYSTALS, NOTHING... I JUST REPLACED TwO PULLYS THT WERE SHOT OUT, AND NOW IM GOING TO ADD FLUID AND CRANK IT OVER TO SEE WHAT IT DOES....🤭 wish me luck!!! Lol
When I first bought the truck it had a slight overheating issue...I replaced the thermostat,(which there wasnt one), the radiator cap, flushed the system 2x, did an oil change, and was just about to do my front suspension when one day I was getting air, started the engine and grind grind bang, there goes the radiator fluid!! The freeze plugs at the bottom of the block blew, my manifold cover was missing unbenounced to me, so in turn they bent the flywheel...I NEVER HAD ANY STEAM, SMOKE, NO MIXTURES OF ANY KIND, HELL IT NEVER FULLY OVER HEATED!! SO IM ASKING WITH THE COMPRESSION TEST ON ALL 8 CYLINDERS COMING BACK AT 125PSI EACH, DO I HAVE A BLOWN ENGINE?? MY HONEST OPINION, NO I DONT...ALL 8 SPARK PLUGS WERE CHARCOAL BLACK...NO CRYSTALS, NOTHING... I JUST REPLACED TwO PULLYS THT WERE SHOT OUT, AND NOW IM GOING TO ADD FLUID AND CRANK IT OVER TO SEE WHAT IT DOES....🤭 wish me luck!!! Lol
I can’t give you a definite answer because there’s more to engine condition than just compression. On any engine, a cold compression check will net different results than a hot compression check and based on your statements so far, the engine was cold when you checked the compression. Additionally, some things, such as a warped head, are not always detectable when the engine is cold.
If the engine starts and will run up to temperature, try checking the compression with the engine up to temp and see what the results are.
November 22nd, 2020, 1:55 PM
#12
CF Monarch
TYPING IN ALL CAPS ONLY HELPS ME SEE THE WORDS MORE CLEARLY BUT OTHERWISE THERE’S NO REASON FOR YOU TO BE DOING SO.
I can’t give you a definite answer because there’s more to engine condition than just compression. On any engine, a cold compression check will net different results than a hot compression check and based on your statements so far, the engine was cold when you checked the compression. Additionally, some things, such as a warped head, are not always detectable when the engine is cold.
If the engine starts and will run up to temperature, try checking the compression with the engine up to temp and see what the results are.
I can’t give you a definite answer because there’s more to engine condition than just compression. On any engine, a cold compression check will net different results than a hot compression check and based on your statements so far, the engine was cold when you checked the compression. Additionally, some things, such as a warped head, are not always detectable when the engine is cold.
If the engine starts and will run up to temperature, try checking the compression with the engine up to temp and see what the results are.
November 22nd, 2020, 2:00 PM
#13
CF Monarch
Ok, so obviously there is some clarification needed....here goes...
When I first bought the truck it had a slight overheating issue...I replaced the thermostat,(which there wasnt one), the radiator cap, flushed the system 2x, did an oil change, and was just about to do my front suspension when one day I was getting air, started the engine and grind grind bang, there goes the radiator fluid!! The freeze plugs at the bottom of the block blew, my manifold cover was missing unbenounced to me, so in turn they bent the flywheel...I NEVER HAD ANY STEAM, SMOKE, NO MIXTURES OF ANY KIND, HELL IT NEVER FULLY OVER HEATED!! SO IM ASKING WITH THE COMPRESSION TEST ON ALL 8 CYLINDERS COMING BACK AT 125PSI EACH, DO I HAVE A BLOWN ENGINE?? MY HONEST OPINION, NO I DONT...ALL 8 SPARK PLUGS WERE CHARCOAL BLACK...NO CRYSTALS, NOTHING... I JUST REPLACED TwO PULLYS THT WERE SHOT OUT, AND NOW IM GOING TO ADD FLUID AND CRANK IT OVER TO SEE WHAT IT DOES....🤭 wish me luck!!! Lol
When I first bought the truck it had a slight overheating issue...I replaced the thermostat,(which there wasnt one), the radiator cap, flushed the system 2x, did an oil change, and was just about to do my front suspension when one day I was getting air, started the engine and grind grind bang, there goes the radiator fluid!! The freeze plugs at the bottom of the block blew, my manifold cover was missing unbenounced to me, so in turn they bent the flywheel...I NEVER HAD ANY STEAM, SMOKE, NO MIXTURES OF ANY KIND, HELL IT NEVER FULLY OVER HEATED!! SO IM ASKING WITH THE COMPRESSION TEST ON ALL 8 CYLINDERS COMING BACK AT 125PSI EACH, DO I HAVE A BLOWN ENGINE?? MY HONEST OPINION, NO I DONT...ALL 8 SPARK PLUGS WERE CHARCOAL BLACK...NO CRYSTALS, NOTHING... I JUST REPLACED TwO PULLYS THT WERE SHOT OUT, AND NOW IM GOING TO ADD FLUID AND CRANK IT OVER TO SEE WHAT IT DOES....🤭 wish me luck!!! Lol
November 22nd, 2020, 2:07 PM
#14
CF Monarch
Ok, so obviously there is some clarification needed....here goes...
When I first bought the truck it had a slight overheating issue...I replaced the thermostat,(which there wasnt one), the radiator cap, flushed the system 2x, did an oil change, and was just about to do my front suspension when one day I was getting air, started the engine and grind grind bang, there goes the radiator fluid!! The freeze plugs at the bottom of the block blew, my manifold cover was missing unbenounced to me, so in turn they bent the flywheel...I NEVER HAD ANY STEAM, SMOKE, NO MIXTURES OF ANY KIND, HELL IT NEVER FULLY OVER HEATED!! SO IM ASKING WITH THE COMPRESSION TEST ON ALL 8 CYLINDERS COMING BACK AT 125PSI EACH, DO I HAVE A BLOWN ENGINE?? MY HONEST OPINION, NO I DONT...ALL 8 SPARK PLUGS WERE CHARCOAL BLACK...NO CRYSTALS, NOTHING... I JUST REPLACED TwO PULLYS THT WERE SHOT OUT, AND NOW IM GOING TO ADD FLUID AND CRANK IT OVER TO SEE WHAT IT DOES....🤭 wish me luck!!! Lol
When I first bought the truck it had a slight overheating issue...I replaced the thermostat,(which there wasnt one), the radiator cap, flushed the system 2x, did an oil change, and was just about to do my front suspension when one day I was getting air, started the engine and grind grind bang, there goes the radiator fluid!! The freeze plugs at the bottom of the block blew, my manifold cover was missing unbenounced to me, so in turn they bent the flywheel...I NEVER HAD ANY STEAM, SMOKE, NO MIXTURES OF ANY KIND, HELL IT NEVER FULLY OVER HEATED!! SO IM ASKING WITH THE COMPRESSION TEST ON ALL 8 CYLINDERS COMING BACK AT 125PSI EACH, DO I HAVE A BLOWN ENGINE?? MY HONEST OPINION, NO I DONT...ALL 8 SPARK PLUGS WERE CHARCOAL BLACK...NO CRYSTALS, NOTHING... I JUST REPLACED TwO PULLYS THT WERE SHOT OUT, AND NOW IM GOING TO ADD FLUID AND CRANK IT OVER TO SEE WHAT IT DOES....🤭 wish me luck!!! Lol
November 23rd, 2020, 8:49 AM
#15
CF Veteran
I don’t think this engine is “blown” but I’m not going to agree that it’s fine either based solely on one compression test. There’s a lot of possible problems following the issue the OP described.
December 3rd, 2020, 9:59 AM
#16
CF Beginner
Thread Starter
98 5.7 vortec help
The theromstat also slowly restricts the flow of coolant through the radiator as to give the coolant time to "cool". Old school was remove the thermostat if you had an over heating issue. Overheating issues are caused generally by lack of maintenance. I am sorry you are having this issue, but understand "we" are not there, and trying to help with your issue.
* thank you so much for all your help and yes I do realize that u all arent here with me...lord only knows I wish some of u were!! I had a supposed "master mechanic" helping me for a bit...come to find out he is a psycho and expected me to either pay him with sex or other wise...kicked him to the curb...thing is I dont know exactly wht he has done to my truck and the jerk wont tell me he only threatens me...needless to say I'm up ****s creek without a paddle!!! I've put everything back together, tightened up all tht was loose, unbelievably there was alot, and now it wont turn over!! So either he killed my starter or hell I dont know....I'm so frustrated its sickening!! I cant get any honest help where I'm at, everyone wants to make sure it never runs, yet acts like they r helping...does anyone know an honest, not psychotic, or crazy mechanic in the orange county, ca area that can help me?? I'm so desperate I'm at the point where I will do just abt Anything to get some help with it....hahaha no not anything sexual!! Not my get down!! Just want someone real!!
Forgot to mention I also replaced 2 pulleys, bearings were toast....all fluids are fine, but now I've noticed the steering box leaking, could someone have messed with it to cause it to leak?? Can it b fixed without having to buy a new one?? I'll go RIP it off another truck if I have to!! Lol...I love pick ur parts so thts not an issue for me I'm just trying to go as cheap as possible for now til my finances change....I so appreciate all ur comments and feedback!! Thanx again for taking the time to actually read and reply...means alot!!
Last edited by Kristie-Anna; December 3rd, 2020 at 10:05 AM.
January 17th, 2023, 12:42 PM
#17
CF Beginner
Thread Starter
re: engine block cracked
Last edited by Kristie-Anna; January 17th, 2023 at 12:47 PM. Reason: stopped letting me write the current response
January 21st, 2023, 1:45 PM
#18
CF Veteran
Update on my 98, my engine is not cracked, actually starts very strong and stays strong... my main issue is a knock and again a leaking freeze plug {which had help to leak}, i need a diagram on the freeze plug locations and the knock sensor locations. i have had a lot of people mess with my truck why? my only guess is they cant handle seeing a chick with a 4x4....who knows....if anyone can help with these diagrams id appreciate it. Thanx
The knock sensors are threaded into the bottom of the block on either side, just above the oil pan.
I can’t recall for sure if it applies to these engines but some of the knock sensors doubled as a drain plug for the block coolant jackets, so be prepared to catch coolant if you remove them.
January 25th, 2023, 9:52 AM
#19
CF Beginner
Thread Starter
RE: freeze plug location
I’m not having any luck finding a diagram, but there are 2 plugs on each side of the block - 1 near the front and 1 near the back. The fronts are usually accessible without too much trouble but the ones at the back typically require starter and/or oil filter removal.
The knock sensors are threaded into the bottom of the block on either side, just above the oil pan.
I can’t recall for sure if it applies to these engines but some of the knock sensors doubled as a drain plug for the block coolant jackets, so be prepared to catch coolant if you remove them.
The knock sensors are threaded into the bottom of the block on either side, just above the oil pan.
I can’t recall for sure if it applies to these engines but some of the knock sensors doubled as a drain plug for the block coolant jackets, so be prepared to catch coolant if you remove them.
yes im learning as i go, so please bare with me if some of my questions seem immature. i want to know everything i can before i just jump into something.
your help is greatly appreciated..thank you for taking time out to answer my questions.
January 25th, 2023, 11:58 AM
#20
CF Veteran
Where did you find that the ECM has to be reset for knock sensor replacement?
GM will often recommend disconnecting the negative battery cable when servicing engine control components, and that will often reset the adaptive memory of the ECM, but to the best of my knowledge, it’s not a requirement.
There’s also a knock sensor module portion of the PCM that can be replaced but I’ve never seen one go bad or require replacement.
Since you’re learning, here’s some FYI -
Knock sensors in particular are just an input signal device - assuming the ECM is functioning correctly and the wiring is in tact, the ECM will immediately recognize a new/different signal from the sensor and adjust accordingly.
The point of knock sensors is to detect spark knock (pinging) and alert the ECM to retard the ignition timing in order to resolve the ping.
GM will often recommend disconnecting the negative battery cable when servicing engine control components, and that will often reset the adaptive memory of the ECM, but to the best of my knowledge, it’s not a requirement.
There’s also a knock sensor module portion of the PCM that can be replaced but I’ve never seen one go bad or require replacement.
Since you’re learning, here’s some FYI -
Knock sensors in particular are just an input signal device - assuming the ECM is functioning correctly and the wiring is in tact, the ECM will immediately recognize a new/different signal from the sensor and adjust accordingly.
The point of knock sensors is to detect spark knock (pinging) and alert the ECM to retard the ignition timing in order to resolve the ping.
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