98 sc2 trying to get oil consumption and MPG in check
#1
05-28-2022, 09:41 AM
98 sc2 trying to get oil consumption and MPG in check
My saturn sat in my neighbors driveway to my knowledge for 8 years without being driven. Finally talked them into selling it to me for 1k bucks had 60k miles. I have driven the heck out of this car as a car pool vehicle. Not the best for that, but it worked hauling me and 3 other big fellas 200 miles a day on and off for a decade. Suspension, steering, everything underneath shot. All moog part replacement. Wheel bearings replaced. Leaking plastic valve cover swapped with the aluminum cover, fixed. Now I'm trying to get the carbon build up cleaned out. Oil consumption is getting bad. I do drive it pretty rough some days but I do keep up with maintenence. Mpg is in the high to mid 20's. Pistons are black as coal!!! Has a stutter when I take off and start winding it up. It loose rpm loose rpm then boom takes off. What the heck can that be. Not being rough on it, when it happens can't find a patern. New pcv valve. Put in a catch can last week rebuilt injectors. Needs a gas cap. Has 167k so I'm thinking millions of miles to go before I let go of this little car!! New plugs last week after a piston soak/seafoam down the throttle body. What a smoke show, , , ,for miles!!! Feels great but mpg, the stutter and oil consumption
#2
05-28-2022, 10:12 AM
I suspect that at 167k miles your car needs new rings, S series cars are known to wear rings. Oil use also tends to cause catalytic converter failure. They are designed to burn hydrocarbons not oil.
Welcome to the forum. Derf and Rube are the resident S series experts.
Welcome to the forum. Derf and Rube are the resident S series experts.
#3
05-28-2022, 06:02 PM
Until yesterday, it had been 7 years since I had an S series car. Derf has learned a whole lot about them in those 7 years. As for decarbonizing one, I'm still old school and use a spray bottle full of water. I use a small spray bottle. About 8 oz. sprayed into the throttle body with the car running and my hand on the throttle cable. If it starts to bog down, then I increase the throttle. Of course, if the cat con is getting clogged, this MIGHT finish it off. And you could always try a little thicker oil in it if you don't want to do a rebuild. New rings and valve seals could do wonder for it, but if you go as far as re-ringing it, you might as well do a complete rebuild.
#5
05-28-2022, 11:20 PM
Not for sure on the oil/1k. But I'm thinking a quart per fill up so 3 quarts/1k roughly. Watched a video on the water sprayed into the throttle body, and that's all I've ever did about carbon until a few weeks ago. In the video the water cleaned off some rust but didn't touch the carbon. I'm going to try some throttle body cleaner through the manifold. Where the pcv valve tubing dumps the fumes. Anyone think the intermittent hesitation in acceleration then feels like it kicked in an afterburner could be the fuel pump? I don't see an entire rebuild in my future. At 167k it better have some more to go
#6
06-01-2022, 08:13 PM
Sorry for the delay in answering but I drove to Atlanta and Alabama and then flew back since you posted.
3q/1k equals 9 quarts per 3K mi, which is only 8 q above the supposed Saturn defined limit which I always thought was BS anyway.
Your oil control rings are thoroughly varnished and stuck in their channels. The oil goes wherever it wants.
Compression rings are most surely worn. A simple compression test will show you the general health. 180 is the service limit although I have driven on much lower without misfires or dead misses.
The rest of the oil that gets into the cylinders does so through the valve guide seals. The only way to control that is to replace them. I suspect if you pull all four plugs they will show evidence of oil fouling. This engine is exceptionally efficient at burning oil as I have never trashed a cat con nor had blue smoke at 11 quarts per 3,000 mi.
Normally I would say to switch to synthetic as it seems to disappear more slowly, but with the price of petroleum products where it is, probably not a great idea.
When a car is using this much oil, you can remove carbon all you want, but it will quickly return. Case in point is the EGR valve and the pipe that connects it. The EGR will get called with carbon deposits to the point that the pintle will barely move or it will move slowly through its normal range but not set a code. Some more oil that goes through the cylinders, the more oil combustion residue that gets passed back through the EGR. The passage that feeds the exhaust back to the EGR is usually caked or coated with carbon slime. If the EGR is full of crud, then the crud continues on and coats the passage back to the intake.
I can explain how to remove a large share of the carbon, but you're going to be doing this every 3 months at the rate you are using oil. So there is really no point because it's not going to stabilize the usage anyway.
As others have already said, this engine needs a rebuild upper and lower. You could put a lower mileage donor engine in, but there are certain limitations based on design changes that may make this exceptionally difficult. Plus you really never know what you're getting. Just because it was running when it got to a junkyard doesn't mean it wasn't burning as much oil as yours is.
It is to your financial benefit to either do a complete rebuild and then drive the car into the ground, or sell it as a donor car if the body panels, power windows and regulators work, etc. It all depends on what kind of shape the rest of the vehicle is in.
Be sure to inspect the frame where the control arms bolt to the frame.
As as far as that hesitation goes, it is likely an air fuel mix issue I believe having significant oil in there probably technically screws up the air fuel mix that actually gets into the cylinder. There are other ways for it to get screwed up, but we can start simple.
If it is at right around 2,200 RPM, It may be the ECTS. This used to happen a lot with the original design of the sensor but the all brass sensors do not fail very often. If you buy one from AutoZone it is not calibrated for the S cars. Buy a Delphi from RockAuto.com. Replace the pigtail connector as well If you do so.
3q/1k equals 9 quarts per 3K mi, which is only 8 q above the supposed Saturn defined limit which I always thought was BS anyway.
Your oil control rings are thoroughly varnished and stuck in their channels. The oil goes wherever it wants.
Compression rings are most surely worn. A simple compression test will show you the general health. 180 is the service limit although I have driven on much lower without misfires or dead misses.
The rest of the oil that gets into the cylinders does so through the valve guide seals. The only way to control that is to replace them. I suspect if you pull all four plugs they will show evidence of oil fouling. This engine is exceptionally efficient at burning oil as I have never trashed a cat con nor had blue smoke at 11 quarts per 3,000 mi.
Normally I would say to switch to synthetic as it seems to disappear more slowly, but with the price of petroleum products where it is, probably not a great idea.
When a car is using this much oil, you can remove carbon all you want, but it will quickly return. Case in point is the EGR valve and the pipe that connects it. The EGR will get called with carbon deposits to the point that the pintle will barely move or it will move slowly through its normal range but not set a code. Some more oil that goes through the cylinders, the more oil combustion residue that gets passed back through the EGR. The passage that feeds the exhaust back to the EGR is usually caked or coated with carbon slime. If the EGR is full of crud, then the crud continues on and coats the passage back to the intake.
I can explain how to remove a large share of the carbon, but you're going to be doing this every 3 months at the rate you are using oil. So there is really no point because it's not going to stabilize the usage anyway.
As others have already said, this engine needs a rebuild upper and lower. You could put a lower mileage donor engine in, but there are certain limitations based on design changes that may make this exceptionally difficult. Plus you really never know what you're getting. Just because it was running when it got to a junkyard doesn't mean it wasn't burning as much oil as yours is.
It is to your financial benefit to either do a complete rebuild and then drive the car into the ground, or sell it as a donor car if the body panels, power windows and regulators work, etc. It all depends on what kind of shape the rest of the vehicle is in.
Be sure to inspect the frame where the control arms bolt to the frame.
As as far as that hesitation goes, it is likely an air fuel mix issue I believe having significant oil in there probably technically screws up the air fuel mix that actually gets into the cylinder. There are other ways for it to get screwed up, but we can start simple.
If it is at right around 2,200 RPM, It may be the ECTS. This used to happen a lot with the original design of the sensor but the all brass sensors do not fail very often. If you buy one from AutoZone it is not calibrated for the S cars. Buy a Delphi from RockAuto.com. Replace the pigtail connector as well If you do so.
#7
06-01-2022, 09:15 PM
Thanks for all that wow.
I have a friend helping g me out with a bushing kit on my old f150. It's almost ready to be my daily driver and I'll pop the top on that saturn. So till then, how in the heck do I get rid of the Carbon. I did put in an oil catch can. Definitely checking that sensor compression check by the weekend
#8
06-02-2022, 07:07 AM
You're not going to get rid of the carbon. That's the plain, honest truth. You can get rid of some of it as already stated. derf has pretty well explained to you what's happening. I've known him a long time and this man has researched the hell of out of the S series cars. He knows his stuff and I'm very proud of what he's learned in the time I've been a member here and known him. He's like rust. Never sleeps! LOL
#9
06-02-2022, 08:03 AM
They make oversized pistons and rings for rebuilds where you bore the cylinders a small amount over so cleaning those doesn't make a whole lot of sense. You can try an MMO piston soak to try to free up the oil control rings. The procedure is documented all over the place on the net.
You can also try seafoam. Not together with the piston soak but separately
It is my understanding that the smoke and stench of doing both of these is massive and foul. Do it away from your neighbors If possible because it just reeks. Do not do it inside a closed garage unless you wish to suffocate.
You can clean out the EGR mess temporarily by removing the EGR. Make sure you have a replacement gasket in hand. The pintle has or used to have a torx slot in the end of the pintle. The gap between the outside of the pintle and the opening of the valve is rather small and gunk will accumulate when you are burning that much oil. Soak the EGR valve with carb choke cleaner for about an hour. Pour out whatever comes out and try to spin the pintle gently by hand with a torx driver. This should get easier to do as you continue to clean it. Repeat the process about 10 times. No I'm not joking. Especially if you have never done this for your EGR. There are internal passages you cannot see but can soak in this manner. Ultimately, the pintle needs to move freely up and down / in and out. Do not force it.
When you think it is clean, clean it five more times.
Ask me how I know this. It seems clean, but the PCM commands the EGR to a certain position and if it doesn't get there fast enough, it assumes a malfunction and throws a code for an EGR fault or insufficient flow or both.
So clean, clean, clean, clean, clean.
Next comes the fun part.
w The EGR still removed, spray a healthy amount of carb show cleaner around the inner wall of the pipe that leads to it. Let it soak for 20 min. You will need a friend for this procedure.
USE HEARING PROTECTION. USE HEARING PROTECTION. USE HEARING PROTECTION.
I WILL NOT BE HELD LIABLE FOR YOUR LOSS OF HEARING OR HEARING DAMAGE FOR FAILING TO USE HEARING PROTECTION DURING THIS PROCESS.
Hold a thick towel over where you have sprayed the carb choke cleaner. Hold it tight. Have your buddy start the engine. If you have soaked it long enough, all kinds of half dissolved slime will come flying out of that opening at high velocity. Catch it with the towel or you will be cleaning up your engine bay for hours. You are hearing raw exhaust, hence the hearing protection.
Have your buddy pulse the accelerator to about 2500 to 3,000 RPM to literally blow loose more of the crud. Again hold on to that towel and make sure the ends of it to not get caught up in anything else.
Let it run for a few minutes but don't let it heat all the way up. Turn off the engine, admire the scuzz on the towel, Wait about 5 minutes, then repeat the procedure, spraying more carb and choke cleaner into the EGR inlet pipe. More should come loose now that it is warm. Don't empty an entire can in there at once, remember it is flammable and you don't want to make a mini bomb inside that tube that combusts all at once in the exhaust system.
You can do the same for the outlet pipe from the EGR. The problem is that whatever you shake loose will clog up the intake so it's up to you whether you want to clean that afterwards or just let it be. If you're doing the full rebuild you can probably just soak the intake.
When you are done all of this MMO, seafoam, and EGR cleaning, start the car with the original plugs in it, take it for a drive and work it through the different RPMs.
Then go home, let it cool and change the plugs to new NGK 5643s. These are the OEM stock plugs that GM private labels as AC Delco. They are copper plugs, get them at 0.040, changed them every 36,000. The car's ignition system was designed for copper plugs. There is no reason to spend more or put anything else in. I don't give a crap what anyone else says. I have driven S cars since 1992. If it ain't broke don't fix it. How much extra power are you going to get from an engine that puts out 124 horsepower from a freaking spark plug? Just use them and you avoid 98% of ignition related problems on these engines. And they are dirt cheap.
With the new clean plugs in, go for a drive. See if the hesitation is still there..
Remember, the rate at which you are going through oil is going to gum up this whole system quite quickly. So save yourself a lot of work and just rebuild the thing.
My guess for compression on your vehicle is between 140 and 150.
You can also try seafoam. Not together with the piston soak but separately
It is my understanding that the smoke and stench of doing both of these is massive and foul. Do it away from your neighbors If possible because it just reeks. Do not do it inside a closed garage unless you wish to suffocate.
You can clean out the EGR mess temporarily by removing the EGR. Make sure you have a replacement gasket in hand. The pintle has or used to have a torx slot in the end of the pintle. The gap between the outside of the pintle and the opening of the valve is rather small and gunk will accumulate when you are burning that much oil. Soak the EGR valve with carb choke cleaner for about an hour. Pour out whatever comes out and try to spin the pintle gently by hand with a torx driver. This should get easier to do as you continue to clean it. Repeat the process about 10 times. No I'm not joking. Especially if you have never done this for your EGR. There are internal passages you cannot see but can soak in this manner. Ultimately, the pintle needs to move freely up and down / in and out. Do not force it.
When you think it is clean, clean it five more times.
Ask me how I know this. It seems clean, but the PCM commands the EGR to a certain position and if it doesn't get there fast enough, it assumes a malfunction and throws a code for an EGR fault or insufficient flow or both.
So clean, clean, clean, clean, clean.
Next comes the fun part.
w The EGR still removed, spray a healthy amount of carb show cleaner around the inner wall of the pipe that leads to it. Let it soak for 20 min. You will need a friend for this procedure.
USE HEARING PROTECTION. USE HEARING PROTECTION. USE HEARING PROTECTION.
I WILL NOT BE HELD LIABLE FOR YOUR LOSS OF HEARING OR HEARING DAMAGE FOR FAILING TO USE HEARING PROTECTION DURING THIS PROCESS.
Hold a thick towel over where you have sprayed the carb choke cleaner. Hold it tight. Have your buddy start the engine. If you have soaked it long enough, all kinds of half dissolved slime will come flying out of that opening at high velocity. Catch it with the towel or you will be cleaning up your engine bay for hours. You are hearing raw exhaust, hence the hearing protection.
Have your buddy pulse the accelerator to about 2500 to 3,000 RPM to literally blow loose more of the crud. Again hold on to that towel and make sure the ends of it to not get caught up in anything else.
Let it run for a few minutes but don't let it heat all the way up. Turn off the engine, admire the scuzz on the towel, Wait about 5 minutes, then repeat the procedure, spraying more carb and choke cleaner into the EGR inlet pipe. More should come loose now that it is warm. Don't empty an entire can in there at once, remember it is flammable and you don't want to make a mini bomb inside that tube that combusts all at once in the exhaust system.
You can do the same for the outlet pipe from the EGR. The problem is that whatever you shake loose will clog up the intake so it's up to you whether you want to clean that afterwards or just let it be. If you're doing the full rebuild you can probably just soak the intake.
When you are done all of this MMO, seafoam, and EGR cleaning, start the car with the original plugs in it, take it for a drive and work it through the different RPMs.
Then go home, let it cool and change the plugs to new NGK 5643s. These are the OEM stock plugs that GM private labels as AC Delco. They are copper plugs, get them at 0.040, changed them every 36,000. The car's ignition system was designed for copper plugs. There is no reason to spend more or put anything else in. I don't give a crap what anyone else says. I have driven S cars since 1992. If it ain't broke don't fix it. How much extra power are you going to get from an engine that puts out 124 horsepower from a freaking spark plug? Just use them and you avoid 98% of ignition related problems on these engines. And they are dirt cheap.
With the new clean plugs in, go for a drive. See if the hesitation is still there..
Remember, the rate at which you are going through oil is going to gum up this whole system quite quickly. So save yourself a lot of work and just rebuild the thing.
My guess for compression on your vehicle is between 140 and 150.
#10
09-02-2022, 02:12 PM
Thanks for the tips!
They make oversized pistons and rings for rebuilds where you bore the cylinders a small amount over so cleaning those doesn't make a whole lot of sense. You can try an MMO piston soak to try to free up the oil control rings. The procedure is documented all over the place on the net.
You can also try seafoam. Not together with the piston soak but separately
It is my understanding that the smoke and stench of doing both of these is massive and foul. Do it away from your neighbors If possible because it just reeks. Do not do it inside a closed garage unless you wish to suffocate.
You can clean out the EGR mess temporarily by removing the EGR. Make sure you have a replacement gasket in hand. The pintle has or used to have a torx slot in the end of the pintle. The gap between the outside of the pintle and the opening of the valve is rather small and gunk will accumulate when you are burning that much oil. Soak the EGR valve with carb choke cleaner for about an hour. Pour out whatever comes out and try to spin the pintle gently by hand with a torx driver. This should get easier to do as you continue to clean it. Repeat the process about 10 times. No I'm not joking. Especially if you have never done this for your EGR. There are internal passages you cannot see but can soak in this manner. Ultimately, the pintle needs to move freely up and down / in and out. Do not force it.
When you think it is clean, clean it five more times.
Ask me how I know this. It seems clean, but the PCM commands the EGR to a certain position and if it doesn't get there fast enough, it assumes a malfunction and throws a code for an EGR fault or insufficient flow or both.
So clean, clean, clean, clean, clean.
Next comes the fun part.
w The EGR still removed, spray a healthy amount of carb show cleaner around the inner wall of the pipe that leads to it. Let it soak for 20 min. You will need a friend for this procedure.
USE HEARING PROTECTION. USE HEARING PROTECTION. USE HEARING PROTECTION.
I WILL NOT BE HELD LIABLE FOR YOUR LOSS OF HEARING OR HEARING DAMAGE FOR FAILING TO USE HEARING PROTECTION DURING THIS PROCESS.
Hold a thick towel over where you have sprayed the carb choke cleaner. Hold it tight. Have your buddy start the engine. If you have soaked it long enough, all kinds of half dissolved slime will come flying out of that opening at high velocity. Catch it with the towel or you will be cleaning up your engine bay for hours. You are hearing raw exhaust, hence the hearing protection.
Have your buddy pulse the accelerator to about 2500 to 3,000 RPM to literally blow loose more of the crud. Again hold on to that towel and make sure the ends of it to not get caught up in anything else.
Let it run for a few minutes but don't let it heat all the way up. Turn off the engine, admire the scuzz on the towel, Wait about 5 minutes, then repeat the procedure, spraying more carb and choke cleaner into the EGR inlet pipe. More should come loose now that it is warm. Don't empty an entire can in there at once, remember it is flammable and you don't want to make a mini bomb inside that tube that combusts all at once in the exhaust system.
You can do the same for the outlet pipe from the EGR. The problem is that whatever you shake loose will clog up the intake so it's up to you whether you want to clean that afterwards or just let it be. If you're doing the full rebuild you can probably just soak the intake.
When you are done all of this MMO, seafoam, and EGR cleaning, start the car with the original plugs in it, take it for a drive and work it through the different RPMs.
Then go home, let it cool and change the plugs to new NGK 5643s. These are the OEM stock plugs that GM private labels as AC Delco. They are copper plugs, get them at 0.040, changed them every 36,000. The car's ignition system was designed for copper plugs. There is no reason to spend more or put anything else in. I don't give a crap what anyone else says. I have driven S cars since 1992. If it ain't broke don't fix it. How much extra power are you going to get from an engine that puts out 124 horsepower from a freaking spark plug? Just use them and you avoid 98% of ignition related problems on these engines. And they are dirt cheap.
With the new clean plugs in, go for a drive. See if the hesitation is still there..
Remember, the rate at which you are going through oil is going to gum up this whole system quite quickly. So save yourself a lot of work and just rebuild the thing.
My guess for compression on your vehicle is between 140 and 150.
You can also try seafoam. Not together with the piston soak but separately
It is my understanding that the smoke and stench of doing both of these is massive and foul. Do it away from your neighbors If possible because it just reeks. Do not do it inside a closed garage unless you wish to suffocate.
You can clean out the EGR mess temporarily by removing the EGR. Make sure you have a replacement gasket in hand. The pintle has or used to have a torx slot in the end of the pintle. The gap between the outside of the pintle and the opening of the valve is rather small and gunk will accumulate when you are burning that much oil. Soak the EGR valve with carb choke cleaner for about an hour. Pour out whatever comes out and try to spin the pintle gently by hand with a torx driver. This should get easier to do as you continue to clean it. Repeat the process about 10 times. No I'm not joking. Especially if you have never done this for your EGR. There are internal passages you cannot see but can soak in this manner. Ultimately, the pintle needs to move freely up and down / in and out. Do not force it.
When you think it is clean, clean it five more times.
Ask me how I know this. It seems clean, but the PCM commands the EGR to a certain position and if it doesn't get there fast enough, it assumes a malfunction and throws a code for an EGR fault or insufficient flow or both.
So clean, clean, clean, clean, clean.
Next comes the fun part.
w The EGR still removed, spray a healthy amount of carb show cleaner around the inner wall of the pipe that leads to it. Let it soak for 20 min. You will need a friend for this procedure.
USE HEARING PROTECTION. USE HEARING PROTECTION. USE HEARING PROTECTION.
I WILL NOT BE HELD LIABLE FOR YOUR LOSS OF HEARING OR HEARING DAMAGE FOR FAILING TO USE HEARING PROTECTION DURING THIS PROCESS.
Hold a thick towel over where you have sprayed the carb choke cleaner. Hold it tight. Have your buddy start the engine. If you have soaked it long enough, all kinds of half dissolved slime will come flying out of that opening at high velocity. Catch it with the towel or you will be cleaning up your engine bay for hours. You are hearing raw exhaust, hence the hearing protection.
Have your buddy pulse the accelerator to about 2500 to 3,000 RPM to literally blow loose more of the crud. Again hold on to that towel and make sure the ends of it to not get caught up in anything else.
Let it run for a few minutes but don't let it heat all the way up. Turn off the engine, admire the scuzz on the towel, Wait about 5 minutes, then repeat the procedure, spraying more carb and choke cleaner into the EGR inlet pipe. More should come loose now that it is warm. Don't empty an entire can in there at once, remember it is flammable and you don't want to make a mini bomb inside that tube that combusts all at once in the exhaust system.
You can do the same for the outlet pipe from the EGR. The problem is that whatever you shake loose will clog up the intake so it's up to you whether you want to clean that afterwards or just let it be. If you're doing the full rebuild you can probably just soak the intake.
When you are done all of this MMO, seafoam, and EGR cleaning, start the car with the original plugs in it, take it for a drive and work it through the different RPMs.
Then go home, let it cool and change the plugs to new NGK 5643s. These are the OEM stock plugs that GM private labels as AC Delco. They are copper plugs, get them at 0.040, changed them every 36,000. The car's ignition system was designed for copper plugs. There is no reason to spend more or put anything else in. I don't give a crap what anyone else says. I have driven S cars since 1992. If it ain't broke don't fix it. How much extra power are you going to get from an engine that puts out 124 horsepower from a freaking spark plug? Just use them and you avoid 98% of ignition related problems on these engines. And they are dirt cheap.
With the new clean plugs in, go for a drive. See if the hesitation is still there..
Remember, the rate at which you are going through oil is going to gum up this whole system quite quickly. So save yourself a lot of work and just rebuild the thing.
My guess for compression on your vehicle is between 140 and 150.
first thing I’ve learned is that the ole saturn isn’t burning oil at the rate I stated in the start of the thread. It has a pretty bad leak. I have a few projects going on with the house right now so I can’t get a for sure location. No smoke in the exhaust. Have a compression check kit but again no time to check. I will definitely get on the carbon cleaning of the EGR/tubing. Thank you for the in depth description. The fuel bank is running in the negative numbers. Been a few weeks since I watched the live data but I’m pretty sure that means an air leak.
I honestly don’t think the little fella needs the rebuild. Of course I say that without performing compression check. After next week I’m getting back on it. Hope to catch everyone back on here when I do!