2002 Blazer with Engine Knock After Warming Up
#1
06-13-2016, 08:42 AM
2002 Blazer with Engine Knock After Warming Up
Good Morning -
My wife and I acquired a 2002 Blazer that has a rather bad tick / knock (really it sounds like something in between the two) that is not apparent when the vehicle is first turned on from being cold, however with a couple minutes (as the engine warms up), it gets very noticeable.
On the way home two days ago we noticed the oil pressure was down at 20 on the dash gauge while driving and at 0 when stopped. I checked the oil and it was just slightly over full. Since I really didn't have much of a choice, I went ahead and drove it carefully home after adding some STP treatment to it, which seemed to help the oil pressure, but not the noise.
Yesterday I ran motor flush through it and despite the oil having just been changed not too long ago, after the flush it came out midnight black. I filled it back up with Valvoline High-Mileage, Fram Premo filter, Lucas (1 quart) and Engine Restore - all of which I have used in the same combination in all my vehicles with no issues.
Oil pressure on startup now is around 40 (was around 30), and once it warms up at idle it is about 18 (better than 0). The noise is still very apparent however so I am wondering what the next steps would be.
Suggestions made to me so far:
-----------------------------------
1. Drain all the oil again, fill with Transmission fluid, run at idle for 10 to 30 minutes, drain and fill back with oil. I have seen this successfully fix many a vehicle with oil circulation problems, but have never done it myself as it just seems like a bad idea.
2. Change out the oil pump. While I am not afraid of the 10 hours(ish) it will take me to do this in my gravel driveway, I don't relish the thought. I have access to a garage, but use it sparingly as I rarely have 10 hours I can commit to something at one time. Car work is usually accomplished a few hours each evening when I do it.
3. Change out the oil pump and bearings (since the Pan is off someone said it should be easy enough to do at that point). Not sure as I cannot really find a good repair guide online. May have to order a factory repair manual.
4. Drive it like it is and just swap the motor when it dies. This isn't a terrible choice, but I hate to think I can spend a week or two to fix the problem and avoid having the engine go completely out on me.
So here are the symptoms as best I can describe:
-----------------------
1. Vehicle Starts fine and sounds fine - maybe a very, very faint tick or tap)
2. About 2 minutes of running and noise gets louder. (Oil pressure starts falling)
3. The sound increases or decreases in frequency with the RPM of the motor.
Probably unrelated but will add:
------------------------------------
1. Up to about 1000 RPM, lights flickering in the vehicle. I suspect a bad Alternator, but haven't had time to test yet.
2. There is a code indicating the MAF sensor is malfunctioning.
3. I believe there is a possible misfire code, but haven't pulled it yet. Service Engine Soon light flashes at times.
I have taken a broom handle (poor man's stethascope) and placed all around the external surfaces of the motor top and bottom and cannot locate the area it is coming from. It sounds like it is coming from the oil pan.
So is there a bearing or something in the Oil Pump that could be causing this? My hopes are that I am just facing a situation where the previous owners were not as diligent on maintenance as they could have been and maybe I am just dealing with a plugged filter screen.
What I don't understand is why does it get progressively worse as it heats up. That seems to indicate poor oil circulation to me. If it was something much more serious, wouldn't it be just as noticeable from a cold start?
I also read that it may be an issue with the Lower Intake Manifold gasket? Is there a way to check for that easily?
I am looking for where to start with this as we got a good enough deal on it that I am willing to pay for a new motor and someone to swap it, but if I can fix it for a few hundred dollars and some effort, I prefer that route.
Thank you in Advance!
It is a 4 Door, 4WD 2002 Chevy Blazer. Manufactured 11/01.
My wife and I acquired a 2002 Blazer that has a rather bad tick / knock (really it sounds like something in between the two) that is not apparent when the vehicle is first turned on from being cold, however with a couple minutes (as the engine warms up), it gets very noticeable.
On the way home two days ago we noticed the oil pressure was down at 20 on the dash gauge while driving and at 0 when stopped. I checked the oil and it was just slightly over full. Since I really didn't have much of a choice, I went ahead and drove it carefully home after adding some STP treatment to it, which seemed to help the oil pressure, but not the noise.
Yesterday I ran motor flush through it and despite the oil having just been changed not too long ago, after the flush it came out midnight black. I filled it back up with Valvoline High-Mileage, Fram Premo filter, Lucas (1 quart) and Engine Restore - all of which I have used in the same combination in all my vehicles with no issues.
Oil pressure on startup now is around 40 (was around 30), and once it warms up at idle it is about 18 (better than 0). The noise is still very apparent however so I am wondering what the next steps would be.
Suggestions made to me so far:
-----------------------------------
1. Drain all the oil again, fill with Transmission fluid, run at idle for 10 to 30 minutes, drain and fill back with oil. I have seen this successfully fix many a vehicle with oil circulation problems, but have never done it myself as it just seems like a bad idea.
2. Change out the oil pump. While I am not afraid of the 10 hours(ish) it will take me to do this in my gravel driveway, I don't relish the thought. I have access to a garage, but use it sparingly as I rarely have 10 hours I can commit to something at one time. Car work is usually accomplished a few hours each evening when I do it.
3. Change out the oil pump and bearings (since the Pan is off someone said it should be easy enough to do at that point). Not sure as I cannot really find a good repair guide online. May have to order a factory repair manual.
4. Drive it like it is and just swap the motor when it dies. This isn't a terrible choice, but I hate to think I can spend a week or two to fix the problem and avoid having the engine go completely out on me.
So here are the symptoms as best I can describe:
-----------------------
1. Vehicle Starts fine and sounds fine - maybe a very, very faint tick or tap)
2. About 2 minutes of running and noise gets louder. (Oil pressure starts falling)
3. The sound increases or decreases in frequency with the RPM of the motor.
Probably unrelated but will add:
------------------------------------
1. Up to about 1000 RPM, lights flickering in the vehicle. I suspect a bad Alternator, but haven't had time to test yet.
2. There is a code indicating the MAF sensor is malfunctioning.
3. I believe there is a possible misfire code, but haven't pulled it yet. Service Engine Soon light flashes at times.
I have taken a broom handle (poor man's stethascope) and placed all around the external surfaces of the motor top and bottom and cannot locate the area it is coming from. It sounds like it is coming from the oil pan.
So is there a bearing or something in the Oil Pump that could be causing this? My hopes are that I am just facing a situation where the previous owners were not as diligent on maintenance as they could have been and maybe I am just dealing with a plugged filter screen.
What I don't understand is why does it get progressively worse as it heats up. That seems to indicate poor oil circulation to me. If it was something much more serious, wouldn't it be just as noticeable from a cold start?
I also read that it may be an issue with the Lower Intake Manifold gasket? Is there a way to check for that easily?
I am looking for where to start with this as we got a good enough deal on it that I am willing to pay for a new motor and someone to swap it, but if I can fix it for a few hundred dollars and some effort, I prefer that route.
Thank you in Advance!
It is a 4 Door, 4WD 2002 Chevy Blazer. Manufactured 11/01.
#2
06-13-2016, 01:16 PM
See video in post #1
https://blazerforum.com/forum/2nd-ge...g-valve-87514/
If it sounds like this, then it is a collapsed lifter.
It gets progressively worse as the engine heats up because the oil gets thinner with heat and it leaks out of excessive clearance much more quickly.
The cause for my lifter collapsing was ultimately bad crankshaft bearings and resulting low oil pressure. Was setting a misfire code, and ticking loudly at below 1500 rpm once engine was fully warmed up (driven down the highway). Oil pressure wasn't quite as bad as yours, so it slipped by my test drive. My LIM gasket had previously been changed and I found that many other repairs had been attempted to get rid of the misfire code. Previous owner apparently finally decided to disconnect the SES light, put tape over the terminal, and traded it in. I bought it from that new car dealer. One of the sharpest looking Blazers you will ever see. I paid a premium for it and didn't look it over very carefully - after all, what could be wrong with a vehicle that sharp with only 65K miles? Lucky me. I paid for being stupid.
If the bearings are causing this, there will be considerable metal in the oil. Just catch the first half a quart out of the engine into a mason jar and let it settle overnight - then slowly pour it off. Any visible silver layers appearing near the bottom and you have found your problem.
If bearings are out of the engine, the most cost-effective way to properly repair the vehicle is to get a replacement engine. Once you get the bearing metal distributed throughout the engine, it needs to be torn down 100% completely and washed to get all of it out - metal even gets in the lifters and the valve guides and in behind rings and in cam bearings - and oil passages need plugs removed and brushed out. Anything else is just a shoddy repair. So please keep this in mind if you decide to attempt a crank kit.
I personally like the GM Goodwrench engine because it comes with a 3 year 100,000 mile warranty. Best price I have found on it was through Jegs.com - especially good because they did not require the old engine to be returned and no tax - free shipping. Mine has about 10K miles on it now, and has been great! Don't forget to replace the radiator to get rid of the metal in the oil cooler (absolutely required for warranty), and do something about your oil cooler lines that certainly will be leaking while the engine is out.
This is the engine that you need for a 2002
Chevrolet Performance 12491869, GM Goodwrench 4.3L 262ci V6 Engine | Chevrolet Performance
If you decide to switch the engine, we can certainly help you through the difficult parts. Work on Blazers engines (especially 4x4 Blazers) is best done inside a garage, and a little bit at a time (to prevent big frustrations).
Good luck! Let us know.
https://blazerforum.com/forum/2nd-ge...g-valve-87514/
If it sounds like this, then it is a collapsed lifter.
It gets progressively worse as the engine heats up because the oil gets thinner with heat and it leaks out of excessive clearance much more quickly.
The cause for my lifter collapsing was ultimately bad crankshaft bearings and resulting low oil pressure. Was setting a misfire code, and ticking loudly at below 1500 rpm once engine was fully warmed up (driven down the highway). Oil pressure wasn't quite as bad as yours, so it slipped by my test drive. My LIM gasket had previously been changed and I found that many other repairs had been attempted to get rid of the misfire code. Previous owner apparently finally decided to disconnect the SES light, put tape over the terminal, and traded it in. I bought it from that new car dealer. One of the sharpest looking Blazers you will ever see. I paid a premium for it and didn't look it over very carefully - after all, what could be wrong with a vehicle that sharp with only 65K miles? Lucky me. I paid for being stupid.
If the bearings are causing this, there will be considerable metal in the oil. Just catch the first half a quart out of the engine into a mason jar and let it settle overnight - then slowly pour it off. Any visible silver layers appearing near the bottom and you have found your problem.
If bearings are out of the engine, the most cost-effective way to properly repair the vehicle is to get a replacement engine. Once you get the bearing metal distributed throughout the engine, it needs to be torn down 100% completely and washed to get all of it out - metal even gets in the lifters and the valve guides and in behind rings and in cam bearings - and oil passages need plugs removed and brushed out. Anything else is just a shoddy repair. So please keep this in mind if you decide to attempt a crank kit.
I personally like the GM Goodwrench engine because it comes with a 3 year 100,000 mile warranty. Best price I have found on it was through Jegs.com - especially good because they did not require the old engine to be returned and no tax - free shipping. Mine has about 10K miles on it now, and has been great! Don't forget to replace the radiator to get rid of the metal in the oil cooler (absolutely required for warranty), and do something about your oil cooler lines that certainly will be leaking while the engine is out.
This is the engine that you need for a 2002
Chevrolet Performance 12491869, GM Goodwrench 4.3L 262ci V6 Engine | Chevrolet Performance
If you decide to switch the engine, we can certainly help you through the difficult parts. Work on Blazers engines (especially 4x4 Blazers) is best done inside a garage, and a little bit at a time (to prevent big frustrations).
Good luck! Let us know.
Last edited by LesMyer; 06-13-2016 at 01:43 PM.
#3
06-15-2016, 04:55 AM
Thank you for the quick response. While I probably know the answer to this, I want to throw it out there anyway.
First, I do not have a garage, but do have access to one, however I cannot let a vehicle sit in it so that would be a no go on using a garage. I did an engine swap in a Chevy Astro Van when I was much, much younger.
So, here is the thing that troubles me. First the sound in your video is very similar to the one I am hearing. Second, I ran a second flush cycle through it. I did see a few metal flecks on the Oil plug magnet (probably not a good sign). The troubling part is that it sounds just fine for the first minute after crank and then it gradually gets louder.
Just to throw it out there - is there any merit to just trying to swap out the oil pump and replace the bearings (yes I know it will be hard from underneath the vehicle, but I do have patience and as long as it is in my own driveway I can afford to take my time (a couple hours a night) just to see if there is any improvement? The parts are cheap compared to a new motor. I know this would not be the recommended course of action, but I am just not sure I am up for a DIY motor swap.
I did get a price from a local garage that I trust that will do the swap for $1250.00 (labor). They said they will get prices on options for the motor once I decide whether or not to move forward. If I do let them do the swap and go with the motor you suggested, I would be about 4K into this vehicle with 155K miles on it. KBB is about $3850 in the shape it would be after the motor swap, so I am not too worried about value, I just am not sure if I want to commit to that without at least taking a shot at the pump first.
The ONLY reason I am thinking that it might be minimal problem with the motor is that when cold after first start pressure is good and it sounds fine, but as it warms up the noise starts and gets louder. Is it possible it is just a worn or bad pump not throwing enough oil to the top end - or even maybe that the pump itself is bad and making the noise?
Sorry to sound uneducated, I have done a lot of work on vehicles, but not so much on the internals beyond the heads. Block, crank, main bearings, etc are still an area I have not yet challenged myself with. I guess this might be a good time to do so.
Any advice, opinion would help.
Thank you!
First, I do not have a garage, but do have access to one, however I cannot let a vehicle sit in it so that would be a no go on using a garage. I did an engine swap in a Chevy Astro Van when I was much, much younger.
So, here is the thing that troubles me. First the sound in your video is very similar to the one I am hearing. Second, I ran a second flush cycle through it. I did see a few metal flecks on the Oil plug magnet (probably not a good sign). The troubling part is that it sounds just fine for the first minute after crank and then it gradually gets louder.
Just to throw it out there - is there any merit to just trying to swap out the oil pump and replace the bearings (yes I know it will be hard from underneath the vehicle, but I do have patience and as long as it is in my own driveway I can afford to take my time (a couple hours a night) just to see if there is any improvement? The parts are cheap compared to a new motor. I know this would not be the recommended course of action, but I am just not sure I am up for a DIY motor swap.
I did get a price from a local garage that I trust that will do the swap for $1250.00 (labor). They said they will get prices on options for the motor once I decide whether or not to move forward. If I do let them do the swap and go with the motor you suggested, I would be about 4K into this vehicle with 155K miles on it. KBB is about $3850 in the shape it would be after the motor swap, so I am not too worried about value, I just am not sure if I want to commit to that without at least taking a shot at the pump first.
The ONLY reason I am thinking that it might be minimal problem with the motor is that when cold after first start pressure is good and it sounds fine, but as it warms up the noise starts and gets louder. Is it possible it is just a worn or bad pump not throwing enough oil to the top end - or even maybe that the pump itself is bad and making the noise?
Sorry to sound uneducated, I have done a lot of work on vehicles, but not so much on the internals beyond the heads. Block, crank, main bearings, etc are still an area I have not yet challenged myself with. I guess this might be a good time to do so.
Any advice, opinion would help.
Thank you!
#4
06-15-2016, 09:43 AM
Thank you for the quick response. While I probably know the answer to this, I want to throw it out there anyway.
First, I do not have a garage, but do have access to one, however I cannot let a vehicle sit in it so that would be a no go on using a garage. I did an engine swap in a Chevy Astro Van when I was much, much younger.
So, here is the thing that troubles me. First the sound in your video is very similar to the one I am hearing. Second, I ran a second flush cycle through it. I did see a few metal flecks on the Oil plug magnet (probably not a good sign). The troubling part is that it sounds just fine for the first minute after crank and then it gradually gets louder.
Just to throw it out there - is there any merit to just trying to swap out the oil pump and replace the bearings (yes I know it will be hard from underneath the vehicle, but I do have patience and as long as it is in my own driveway I can afford to take my time (a couple hours a night) just to see if there is any improvement? The parts are cheap compared to a new motor. I know this would not be the recommended course of action, but I am just not sure I am up for a DIY motor swap.
I did get a price from a local garage that I trust that will do the swap for $1250.00 (labor). They said they will get prices on options for the motor once I decide whether or not to move forward. If I do let them do the swap and go with the motor you suggested, I would be about 4K into this vehicle with 155K miles on it. KBB is about $3850 in the shape it would be after the motor swap, so I am not too worried about value, I just am not sure if I want to commit to that without at least taking a shot at the pump first.
The ONLY reason I am thinking that it might be minimal problem with the motor is that when cold after first start pressure is good and it sounds fine, but as it warms up the noise starts and gets louder. Is it possible it is just a worn or bad pump not throwing enough oil to the top end - or even maybe that the pump itself is bad and making the noise?
Sorry to sound uneducated, I have done a lot of work on vehicles, but not so much on the internals beyond the heads. Block, crank, main bearings, etc are still an area I have not yet challenged myself with. I guess this might be a good time to do so.
Any advice, opinion would help.
Thank you!
First, I do not have a garage, but do have access to one, however I cannot let a vehicle sit in it so that would be a no go on using a garage. I did an engine swap in a Chevy Astro Van when I was much, much younger.
So, here is the thing that troubles me. First the sound in your video is very similar to the one I am hearing. Second, I ran a second flush cycle through it. I did see a few metal flecks on the Oil plug magnet (probably not a good sign). The troubling part is that it sounds just fine for the first minute after crank and then it gradually gets louder.
Just to throw it out there - is there any merit to just trying to swap out the oil pump and replace the bearings (yes I know it will be hard from underneath the vehicle, but I do have patience and as long as it is in my own driveway I can afford to take my time (a couple hours a night) just to see if there is any improvement? The parts are cheap compared to a new motor. I know this would not be the recommended course of action, but I am just not sure I am up for a DIY motor swap.
I did get a price from a local garage that I trust that will do the swap for $1250.00 (labor). They said they will get prices on options for the motor once I decide whether or not to move forward. If I do let them do the swap and go with the motor you suggested, I would be about 4K into this vehicle with 155K miles on it. KBB is about $3850 in the shape it would be after the motor swap, so I am not too worried about value, I just am not sure if I want to commit to that without at least taking a shot at the pump first.
The ONLY reason I am thinking that it might be minimal problem with the motor is that when cold after first start pressure is good and it sounds fine, but as it warms up the noise starts and gets louder. Is it possible it is just a worn or bad pump not throwing enough oil to the top end - or even maybe that the pump itself is bad and making the noise?
Sorry to sound uneducated, I have done a lot of work on vehicles, but not so much on the internals beyond the heads. Block, crank, main bearings, etc are still an area I have not yet challenged myself with. I guess this might be a good time to do so.
Any advice, opinion would help.
Thank you!
Myself, I would never repair bad bearings without having the crankshaft ground and a way to clean metal deposits completely out of the engine.
But sometimes even when you try to do it right, everything still gets FUBAR'd. Read my entire thread if you haven't already. Other people get away with doing things I would not predict would work.
It's your money and your effort. Sounds like you want to try, and you don't have to depend on the vehicle. You can always replace the engine later if it doesn't work out for you.
Good luck
Last edited by LesMyer; 06-15-2016 at 09:48 AM.
#5
06-29-2016, 08:07 AM
Thanks for the feedback. Dropped it by my trusted mechanic who I take things to that I don't want or have time to deal with. He confirmed it was a Rod knock and highly recommended swapping the motor with a used or new vs trying to fix the issue with this one.
Result: New Jasper (that is what he has always used and never has had an issue with the motors) motor has been delivered and is being installed over the next couple of days.
He was concerned the cost of the motor exceeded the value of the vehicle (which it almost does), however I got a really good deal on this vehicle and to have a 4 Door Blazer with everything tight and working on it with a new motor seems worth it to me.
I will update this once the new motor is in. I am off to working on a second 2001 Blazer that is much more a project vehicle for my daughter. Looks like a new Intake Manifold Gasket may be getting installed this weekend (again - got a REALLY good price on this one - needed the gasket and heater core).
Result: New Jasper (that is what he has always used and never has had an issue with the motors) motor has been delivered and is being installed over the next couple of days.
He was concerned the cost of the motor exceeded the value of the vehicle (which it almost does), however I got a really good deal on this vehicle and to have a 4 Door Blazer with everything tight and working on it with a new motor seems worth it to me.
I will update this once the new motor is in. I am off to working on a second 2001 Blazer that is much more a project vehicle for my daughter. Looks like a new Intake Manifold Gasket may be getting installed this weekend (again - got a REALLY good price on this one - needed the gasket and heater core).
#6
07-02-2016, 09:45 AM
Thanks for the feedback. Dropped it by my trusted mechanic who I take things to that I don't want or have time to deal with. He confirmed it was a Rod knock and highly recommended swapping the motor with a used or new vs trying to fix the issue with this one.
Result: New Jasper (that is what he has always used and never has had an issue with the motors) motor has been delivered and is being installed over the next couple of days.
He was concerned the cost of the motor exceeded the value of the vehicle (which it almost does), however I got a really good deal on this vehicle and to have a 4 Door Blazer with everything tight and working on it with a new motor seems worth it to me.
I will update this once the new motor is in. I am off to working on a second 2001 Blazer that is much more a project vehicle for my daughter. Looks like a new Intake Manifold Gasket may be getting installed this weekend (again - got a REALLY good price on this one - needed the gasket and heater core).
Result: New Jasper (that is what he has always used and never has had an issue with the motors) motor has been delivered and is being installed over the next couple of days.
He was concerned the cost of the motor exceeded the value of the vehicle (which it almost does), however I got a really good deal on this vehicle and to have a 4 Door Blazer with everything tight and working on it with a new motor seems worth it to me.
I will update this once the new motor is in. I am off to working on a second 2001 Blazer that is much more a project vehicle for my daughter. Looks like a new Intake Manifold Gasket may be getting installed this weekend (again - got a REALLY good price on this one - needed the gasket and heater core).
#7
07-05-2016, 12:39 PM
Thanks again for all the feedback. Wife just picked it up today along with the list of dos and don'ts for the new motor and use can care.
They did flush the oil cooler lines and system as well. New radiator on as well (yes it was required by Jasper). I have just about 800.00 over book value total in this vehicle with a new motor (book value does not account for a new motor), so feel like so far it is a good investment.
I have an issue with another 2000 blazer I picked up that I will post about separately. Thank you again for all your feedback and assistance.
They did flush the oil cooler lines and system as well. New radiator on as well (yes it was required by Jasper). I have just about 800.00 over book value total in this vehicle with a new motor (book value does not account for a new motor), so feel like so far it is a good investment.
I have an issue with another 2000 blazer I picked up that I will post about separately. Thank you again for all your feedback and assistance.
Thread
Thread Starter
Forum
Replies
Last Post
blazer485
2nd Generation S-series (1995-2005) Tech
5
11-24-2013 09:42 AM
Milli
Full Size K5 (1969-1991) GMT415 (1992-1994) Tech
6
04-29-2010 10:35 AM