Apex seal failure due to MOP not working right?
12-19-04, 09:38 AM
#1
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Apex seal failure due to MOP not working right?
I'll be tearing my engine down soon, hopefully between Christmas and New Years...provided I have the time. Anyway...I've been thinking about something, really wondering exactly WHY my engine "blew". I always attributed it to the mods I've done and not having any fuel compensation, but now I wonder.
I had noticed that my oil level NEVER dropped.
Not ever. Certainly not like my FC, which would 'use' a quart of oil in between changes of 2500 miles or so. My FD's oil level was like ETCHED on the dipstick, making me wonder if the MOP was just not working right or at all. I'll check it out once it is out, of course, but COULD a MOP failure cause the apex seals to fail?
I am wondering what I will find as I get the engine disassembled. I am only taking it down to the short block, but surely one can see thru the ports the seals? When my car quit running, I had limped it home after making a hell-run in which it lost power BIG time.
It died several times on the way home, wouldn't idle...and when I finally got it into the garage and was listening to it it made a horrendous screeching wail and then an incredibly loud BANG! BAM! BANG! and just instantly died...like it was locked up. I can turn the engine over by hand, so I don't think anything is wedged....it will be interesting.
Opinions?
I had noticed that my oil level NEVER dropped.
Not ever. Certainly not like my FC, which would 'use' a quart of oil in between changes of 2500 miles or so. My FD's oil level was like ETCHED on the dipstick, making me wonder if the MOP was just not working right or at all. I'll check it out once it is out, of course, but COULD a MOP failure cause the apex seals to fail?
I am wondering what I will find as I get the engine disassembled. I am only taking it down to the short block, but surely one can see thru the ports the seals? When my car quit running, I had limped it home after making a hell-run in which it lost power BIG time.
It died several times on the way home, wouldn't idle...and when I finally got it into the garage and was listening to it it made a horrendous screeching wail and then an incredibly loud BANG! BAM! BANG! and just instantly died...like it was locked up. I can turn the engine over by hand, so I don't think anything is wedged....it will be interesting.
Opinions?
12-19-04, 11:39 AM
#4
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I had a customer that went thru 3 engines with the dealership doing the work. They told him he was driving wrong and that they did not do anything wrong and would not replace the engine again.
Enter me, Thought about what could be causing new engines to pop. When this is a 55 year old doctor( shrink) That was the original owner and the car only had 50K on it.
I tested the OMP and there was no output at all. We replaced the engine AGAIN, And i replaced the OMP at the same time. At this point the owner is looking to sell the car.. 7K miles later and the car runs great and pulls 20 inches of vaccum. The owner has since sold the car but i still work on it.
So long story short yes it can and did cause 3 engines to blow apex seals . I witnessed it first hand 3 times
Enter me, Thought about what could be causing new engines to pop. When this is a 55 year old doctor( shrink) That was the original owner and the car only had 50K on it.
I tested the OMP and there was no output at all. We replaced the engine AGAIN, And i replaced the OMP at the same time. At this point the owner is looking to sell the car.. 7K miles later and the car runs great and pulls 20 inches of vaccum. The owner has since sold the car but i still work on it.
So long story short yes it can and did cause 3 engines to blow apex seals . I witnessed it first hand 3 times
12-19-04, 11:53 AM
#5
Constant threat
Thread Starter
Originally Posted by BigIslandSevens
I had a customer that went thru 3 engines with the dealership doing the work. They told him he was driving wrong and that they did not do anything wrong and would not replace the engine again.
Enter me, Thought about what could be causing new engines to pop. When this is a 55 year old doctor( shrink) That was the original owner and the car only had 50K on it.
I tested the OMP and there was no output at all. We replaced the engine AGAIN, And i replaced the OMP at the same time. At this point the owner is looking to sell the car.. 7K miles later and the car runs great and pulls 20 inches of vaccum. The owner has since sold the car but i still work on it.
So long story short yes it can and did cause 3 engines to blow apex seals . I witnessed it first hand 3 times
Enter me, Thought about what could be causing new engines to pop. When this is a 55 year old doctor( shrink) That was the original owner and the car only had 50K on it.
I tested the OMP and there was no output at all. We replaced the engine AGAIN, And i replaced the OMP at the same time. At this point the owner is looking to sell the car.. 7K miles later and the car runs great and pulls 20 inches of vaccum. The owner has since sold the car but i still work on it.
So long story short yes it can and did cause 3 engines to blow apex seals . I witnessed it first hand 3 times
Thanks!
12-19-04, 12:11 PM
#6
Rotary Enthusiast
It would be easy if you have a fully programmable ECU. You can monitor the omp position feed back while you step on the gas.
If that is not an option, jumper and measure the voltage at pin 3A on the ecu connector. It should be approximately 1.1V at idle and change with rpm, not exceeding 4.7V.
If that is not an option, jumper and measure the voltage at pin 3A on the ecu connector. It should be approximately 1.1V at idle and change with rpm, not exceeding 4.7V.
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12-19-04, 12:50 PM
#8
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Originally Posted by BigIslandSevens
I had a customer that went thru 3 engines with the dealership doing the work. They told him he was driving wrong and that they did not do anything wrong and would not replace the engine again.
Enter me, Thought about what could be causing new engines to pop. When this is a 55 year old doctor( shrink) That was the original owner and the car only had 50K on it.
I tested the OMP and there was no output at all. We replaced the engine AGAIN, And i replaced the OMP at the same time. At this point the owner is looking to sell the car.. 7K miles later and the car runs great and pulls 20 inches of vaccum. The owner has since sold the car but i still work on it.
So long story short yes it can and did cause 3 engines to blow apex seals . I witnessed it first hand 3 times
Enter me, Thought about what could be causing new engines to pop. When this is a 55 year old doctor( shrink) That was the original owner and the car only had 50K on it.
I tested the OMP and there was no output at all. We replaced the engine AGAIN, And i replaced the OMP at the same time. At this point the owner is looking to sell the car.. 7K miles later and the car runs great and pulls 20 inches of vaccum. The owner has since sold the car but i still work on it.
So long story short yes it can and did cause 3 engines to blow apex seals . I witnessed it first hand 3 times
12-19-04, 12:57 PM
#9
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I did as Trex mentioned. Which is the same thing essentially as the Speacial diagnostic tool does. The voltage was not correct at idle and it did not increase at all either. So i replaced it and rechecked everything was proper.
Mat,- The engines lasted around 2k miles each time. And he rarely drove the car but for a couple weeks out of the year and occasional weekends. Each time the "warranty" Time period had expired. not the milage. The local dealer just didn't look for anything else besides the "your engine is popped" diagnosis. And did not bother to ask themselves WHY!!! Typical mazda service department.
The car was sold and the new owner drives it quite a bit. almost his daily driver now
However i just saw it( the car) on the road 2 days ago with a new person i did not recognize driving it. They wouldn't even look over when i revved the FC and honked and yelled But the car drives awsome now and i fixed another issue that they the dealer failed to see.Turbo control related
Installed a KOYO for him and haven't heard from him since...which in my book as a technician, is a good thing.
Mat,- The engines lasted around 2k miles each time. And he rarely drove the car but for a couple weeks out of the year and occasional weekends. Each time the "warranty" Time period had expired. not the milage. The local dealer just didn't look for anything else besides the "your engine is popped" diagnosis. And did not bother to ask themselves WHY!!! Typical mazda service department.
The car was sold and the new owner drives it quite a bit. almost his daily driver now
However i just saw it( the car) on the road 2 days ago with a new person i did not recognize driving it. They wouldn't even look over when i revved the FC and honked and yelled But the car drives awsome now and i fixed another issue that they the dealer failed to see.Turbo control related Installed a KOYO for him and haven't heard from him since...which in my book as a technician, is a good thing.
12-19-04, 03:16 PM
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well, some oils burn and some dont... for example, when i use to use castrol GTX 20/50, i use to have to fill up a 1/4 of a quart between oil changes.... but i have switched to using chevron turbo 20/50 and it hasnt done it yet. i asked my mechanic firend and he said that the chevron doesnt burn....
so i have a question too, is this good or bad??? and does it burn?
so i have a question too, is this good or bad??? and does it burn?
12-19-04, 05:45 PM
#13
Rotary Enthusiast
That's kind of bad. The big argument between synthetic vs. organic was because of the fact that early synthetics doesn't burn off cleanly during the combution cycle.
Even if the oil doesn't burn, with a working OMP oil is still being injected into the combustion chamber at the same rate. So the oil consumption should still be the same. So it doesn't matter if the oil burns or not. But if you are using an oil that doesn't burn at all, you need to be concerned with where the injected oil is going to.
Even if the oil doesn't burn, with a working OMP oil is still being injected into the combustion chamber at the same rate. So the oil consumption should still be the same. So it doesn't matter if the oil burns or not. But if you are using an oil that doesn't burn at all, you need to be concerned with where the injected oil is going to.
12-19-04, 06:01 PM
#14
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Bajaman- He was not savvy to the ways of the rotor. It took not being able to start the car before he towed it into the dealer for another engine,..2 more times. And as i said the time that the 2k miles were put on was in over 1 1/2 year period each time. he rarely drove it.
I have educated the new owners that they need to be very aware of a few critical components to make sure the car stays happy.
Other than the KOYO and a turbo timer, the car is completely stock.
I have educated the new owners that they need to be very aware of a few critical components to make sure the car stays happy.
Other than the KOYO and a turbo timer, the car is completely stock.
12-19-04, 06:55 PM
#15
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Thread Starter
Originally Posted by rzograbian
well, some oils burn and some dont... for example, when i use to use castrol GTX 20/50, i use to have to fill up a 1/4 of a quart between oil changes.... but i have switched to using chevron turbo 20/50 and it hasnt done it yet. i asked my mechanic firend and he said that the chevron doesnt burn....
so i have a question too, is this good or bad??? and does it burn?
so i have a question too, is this good or bad??? and does it burn?
I always used a pint of Marvel Mystery oil with each fill-up, so that was like a pre-mix in a way.....
12-19-04, 11:28 PM
#16
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1 point i feel i gotta put in here,,,,as far as i understand the OMP always injects oil,,,the ECU just controls the amount between 2 fixed points. does so by using a variable resistor and motor to control a cam. (maybe a blocked oil way,,metering pipe or injector was at fault) if the motor or resisitor in the pump failes the ECU can detect this and puts the car in limp mode,,,(first hand experience)
12-20-04, 12:26 AM
#17
A couple of things.
1) IF your engine blows apex seals and loses all compression on one rotor, then that rotor and rotorhousing are almost definitely toast, due to deep scratches and gouges left by the fragments of seals as they exit. Regardless of the reason, be it forcible break such as detonation, or breakage due to wear or other factors, the end result looks the same.
The seal pieces fall out of the groove (while running, mind you) and get wedged in place. At certain rotational points in the engine there is 2-3" of gap between the rotor and housing, and others there is about 1mm between the rotor and housing, and obviously a 2mm seal fragment will not fit here. The damage is usually at the closing points of the rotation, right by the exhaust port and right by the T plug on the rotorhousing, and on all 3 faces of the rotor.
As soon as you feel the power loss and let off to see what happened, the damge is already done, and you will not cause further damage by driving it. At this point the one rotor is freewheeling not doing anything, the other is carrying the car.
It is possible, but far less common, to see a single seal or 2 crack, but the pieces be so small that they do no damage on their way out, or even that they stay in place and do not fall out. It's even possible for the center of a seal to crack during the "power" phase of combustion and thus it falls right out the exhaust port unimpeded and does no damage to anything else since it does not float around inside during the other "phases" such as intake and compression. These cases are very rare though.
Hell, I've even see a few times (more so on turbo models) where a seal exits the front rotorhousing, hits the exhaust manifold or turbine wheel just right, and gets thrown back into the rear rotorhousing, entering there and doing more damage to that chamber. You know this when the entire engine loses all compression at one time, and you find apex seal damage to both chambers. You can spot it because one rotor will have damage all over the width of the rotor, this was the first to blow, and fragments of it went out and then into the opposing chamber, and you'll see a single scratch from that one single piece, which then broke those seals. Talk about a heartbreaker, there is nothing to rebuild from when this rare phenomenon happens.
2) IF you want to see why the seals blew, take a look at the remaining seals on that or the opposing rotor. A new apex seal measures right around .335-.330". From my experience, most engines wear seals at the rate of 1 thousandth of an inch per thousand miles of use (give or take for OMP/premix rate changes, excess babying or abuse, etc.). For instance, if I take apart an engine with a documented 84k miles, and I know that an apex seal new would be .330" in height, then I would expect that used seal to be around .240-.260" in height.
That said, if you take apart an engine with 20k miles on a rebuild that blew seals, measure your remaining seals to see why. IF they're worn excessively (say, 80 thousandths) for the mileage/use they've seen, then something is wrong, either you have a problem with warpage, compression sealing surface, bad batch of seals, or a bad OMP or premix ratio, or maybe you've been running so rich that you wash the housings protective oil coating (omp/premix injected) off with gasoline injected every rotation. OR maybe you did an exhaust port and didn't bevel the closing edge and this caused the seal to flex into the port and get excess material shaved off each high rpm pass it made.
IF you have a higher mileage engine and there is significant seal wear, you can still check the problems above, but more likely it was just a set of worn out seals. Contrary to popular belief apex seals do wear quite a bit during a 100k mile span. The more a seal wears down in height, the weaker it gets, especially a stock 3pc seal. They can wear down so much that the thin top sealing piece can roll right out of it's groove during a hard run and cause massive damage. This is what I'd consider normal for an engine with 100k or more miles. Consider that with harder driving comes more seal wear, so if you treat the car rough, you can cause 150k miles of seal wear in 50k miles.
IF these seals are still close to their original height with very little wear, then you know they didnt break due to being worn down and weakened. This means you forcibly broke them due to pinging or overrevving. Usually when this happens the weakest point of the seal (the tip of the longest sealing piece, where it meets the small corner assist piece) breaks off in a piece a mm or 2 wide. This is signature of detonation break. You can take a 2000 mile rebuild and break it this way. Sometimes the small piece that got broken doesnt do much damage, sometimes it flies around inside and takes larger pieces of seal out with it.
So, even though the 2 different means of breaking apex seals (wear, and force) leave pretty much the same trail of damage behind (destroyed rotor and housing) you can often tell which was the culprit by measuring height of the remaining seals to figure out if there was enough wear to cause a normal breakage, or if it was a more forcible breakage of a non-worn seal.
1) IF your engine blows apex seals and loses all compression on one rotor, then that rotor and rotorhousing are almost definitely toast, due to deep scratches and gouges left by the fragments of seals as they exit. Regardless of the reason, be it forcible break such as detonation, or breakage due to wear or other factors, the end result looks the same.
The seal pieces fall out of the groove (while running, mind you) and get wedged in place. At certain rotational points in the engine there is 2-3" of gap between the rotor and housing, and others there is about 1mm between the rotor and housing, and obviously a 2mm seal fragment will not fit here. The damage is usually at the closing points of the rotation, right by the exhaust port and right by the T plug on the rotorhousing, and on all 3 faces of the rotor.
As soon as you feel the power loss and let off to see what happened, the damge is already done, and you will not cause further damage by driving it. At this point the one rotor is freewheeling not doing anything, the other is carrying the car.
It is possible, but far less common, to see a single seal or 2 crack, but the pieces be so small that they do no damage on their way out, or even that they stay in place and do not fall out. It's even possible for the center of a seal to crack during the "power" phase of combustion and thus it falls right out the exhaust port unimpeded and does no damage to anything else since it does not float around inside during the other "phases" such as intake and compression. These cases are very rare though.
Hell, I've even see a few times (more so on turbo models) where a seal exits the front rotorhousing, hits the exhaust manifold or turbine wheel just right, and gets thrown back into the rear rotorhousing, entering there and doing more damage to that chamber. You know this when the entire engine loses all compression at one time, and you find apex seal damage to both chambers. You can spot it because one rotor will have damage all over the width of the rotor, this was the first to blow, and fragments of it went out and then into the opposing chamber, and you'll see a single scratch from that one single piece, which then broke those seals. Talk about a heartbreaker, there is nothing to rebuild from when this rare phenomenon happens.
2) IF you want to see why the seals blew, take a look at the remaining seals on that or the opposing rotor. A new apex seal measures right around .335-.330". From my experience, most engines wear seals at the rate of 1 thousandth of an inch per thousand miles of use (give or take for OMP/premix rate changes, excess babying or abuse, etc.). For instance, if I take apart an engine with a documented 84k miles, and I know that an apex seal new would be .330" in height, then I would expect that used seal to be around .240-.260" in height.
That said, if you take apart an engine with 20k miles on a rebuild that blew seals, measure your remaining seals to see why. IF they're worn excessively (say, 80 thousandths) for the mileage/use they've seen, then something is wrong, either you have a problem with warpage, compression sealing surface, bad batch of seals, or a bad OMP or premix ratio, or maybe you've been running so rich that you wash the housings protective oil coating (omp/premix injected) off with gasoline injected every rotation. OR maybe you did an exhaust port and didn't bevel the closing edge and this caused the seal to flex into the port and get excess material shaved off each high rpm pass it made.
IF you have a higher mileage engine and there is significant seal wear, you can still check the problems above, but more likely it was just a set of worn out seals. Contrary to popular belief apex seals do wear quite a bit during a 100k mile span. The more a seal wears down in height, the weaker it gets, especially a stock 3pc seal. They can wear down so much that the thin top sealing piece can roll right out of it's groove during a hard run and cause massive damage. This is what I'd consider normal for an engine with 100k or more miles. Consider that with harder driving comes more seal wear, so if you treat the car rough, you can cause 150k miles of seal wear in 50k miles.
IF these seals are still close to their original height with very little wear, then you know they didnt break due to being worn down and weakened. This means you forcibly broke them due to pinging or overrevving. Usually when this happens the weakest point of the seal (the tip of the longest sealing piece, where it meets the small corner assist piece) breaks off in a piece a mm or 2 wide. This is signature of detonation break. You can take a 2000 mile rebuild and break it this way. Sometimes the small piece that got broken doesnt do much damage, sometimes it flies around inside and takes larger pieces of seal out with it.
So, even though the 2 different means of breaking apex seals (wear, and force) leave pretty much the same trail of damage behind (destroyed rotor and housing) you can often tell which was the culprit by measuring height of the remaining seals to figure out if there was enough wear to cause a normal breakage, or if it was a more forcible breakage of a non-worn seal.
12-20-04, 01:02 AM
#18
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Apex seals don't "blow" from lack of oil, they warp from the heat. I would suspect your OMP was working ok because your seals would have warped earlier under boost before you busted the motor, which they didn't. You know instantly because you don't have a good idle, it usually bounces and the car is very hard to start when hot if you can start it at all.
You should be using some oil and the fact you aren't seems odd. Find someone with a Power FC and remove your stock ECU. (after you have your car back together) Start the car and at idle and go to the screen that showns "sensors", look at the OMP, it should be reading 1.17 volts. If it is black with 0.00 it's bad or the connection is bad. Also make sure you getting oil from your oil lines. Look at your OMP lines and see if you have oil dripping out of them. Your engine now is stripped so walk over and look.
You should be using some oil and the fact you aren't seems odd. Find someone with a Power FC and remove your stock ECU. (after you have your car back together) Start the car and at idle and go to the screen that showns "sensors", look at the OMP, it should be reading 1.17 volts. If it is black with 0.00 it's bad or the connection is bad. Also make sure you getting oil from your oil lines. Look at your OMP lines and see if you have oil dripping out of them. Your engine now is stripped so walk over and look.
12-20-04, 01:13 AM
#19
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I don't think bajaman has actually taken it down yet. To say that i don't know for sure that "he" knows That the seal is cracked/blown rather than just warped. I think he was just looking for Things to check on while going in. Kevin's Novel was great info That is how you tear a engine down.. You spec EVERYTHING out to find the cause of the problem.
That is how you tear a engine down.. You spec EVERYTHING out to find the cause of the problem.
12-20-04, 01:40 AM
#21
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So do those use the stock or SS metering lines? I didn't see any mention on that part. Also do you have any info on why it makes a difference if it is a electric pump or mechanical? Since it is using an alternate source of oil why would it need to tie into the ECU system? If it still ties in to the ECU,. I see no "real" advancement from the stock OMP.
Maybe i am just tired and have been painting too much today and have confused myself Or is the price difference just due to the amount of Aluminum used in the pump housing?
Also fwiw: it is Now up to "you" to be the Check engine light and remember to check the oil level all the time.( Meaning you are now the sole monitoring system for the OMP...not the ECU) Based on the amount of things for one to remember already, most would be better off letting the ECU watch over this function. imo or as Glass man said, Pre-Mix
Maybe i am just tired and have been painting too much today and have confused myself
Or is the price difference just due to the amount of Aluminum used in the pump housing?Also fwiw: it is Now up to "you" to be the Check engine light and remember to check the oil level all the time.( Meaning you are now the sole monitoring system for the OMP...not the ECU) Based on the amount of things for one to remember already, most would be better off letting the ECU watch over this function. imo or as Glass man said, Pre-Mix
Last edited by BigIslandSevens; 12-20-04 at 01:48 AM.
12-20-04, 01:53 AM
#22
Those things just go between the block and the stock OMP pump, keeping the same lines and such. It just intercepts flow of motor oil into the stock pump, and instead lets you supply whatever source of oil you want to via the inlet there for the stock pump to inject.
12-20-04, 02:04 AM
#23
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does it have a fail safe built in .in the event that you forget to keep the oil full? Does it revert back to engine oil system, or are you up the same creek. Thanks for the explanation on where it goes inline
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