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2G New car, bunch of problems. High Oil Viscosity, Low Oil Pressure, Overboosting, transmission slipping maybe?

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JayyDSM_

Supporting Member
38
11
Jun 3, 2018
Huntsville, Alabama
I just purchased a Maroon 98’ GSX, Autotragic, drove it 2.5 hours home today and after the 2 hour mark it started wanting to act up.

It gave me low oil pressure and when I went to check the oil, the dipstick was super hot and the oil coming out of it had the consistency of water.

The car is having Overboosting issues and the BOV is not releasing as much boost as it should be. Could this cause the oil temperature to rise so high it increases the oil viscosity?

It also was getting about 10mpg on my way home, filled up a full tank of 93 and I’ve driven 120 miles and I’m on a quarter tank of fuel now.

Automatic trans is also doing what feels like it is slipping, or it could be over drive kicking in and causing it to cut timing. If I give the car any acceleration, over 3.5k rpms the trans slips itself into a neutral state and stops putting power down and starts doing what almost looks like a pop tune.

Any recommendations, or anyone else gone through anything similiar, any advice helps, tomorrow I plan to fiddle with the BOV and open it up completely.

It has a Greddy type S BOV and on my entire way home I only heard the blow off valve twice that I can recall.

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The BOV only releases EXCESS pressure as when you are boosting and close the throttle fast.
SMELL your oil, it could very well be fuel contaminated from washing the cylinders for that 2 hr drive. Was it overfull too?
Also, clarification on viscosity. As it gets thinner, it is losing viscosity. An oil cooler will help but a lot of us don't run one and have no issues. Since the mileage was horrible, I suspect too much fuel and some may be getting past the rings and thinning the oil. If the car has ECMLink, get a log of it running so we can look at the settings.
Also, check and change that thin oil to a heavy weight, 20w50 oil. That should bring the pressure back up. If not, the bearings may have been running in too thin of oil and wore some material down (they should never touch, the oil keeps a protective film between the crank and the bearings when it is the right viscosity)
The transmission slipping could very well be a dirty filter so not enough pressure to hold clutch packs tight. Would be a good time to change it out also.
BTW.....NICE LOOKING CAR, KEEP THE AUTOMATIC!!!! :thumb:
Marty
 
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I'm having issues with the car I bought recently, my 98 GSX AUTO, where the car does not like to release boost, I have a greedy type-s bov, and the stock turbo and internal wastegate, some vacuum lines may not be properly connected or I may be leaking boost. All I know is that the car is dumping fuel, my boost gauge does not increase it just sits and remains idle at 0, although it sounds and feels like its building boost. I have attached a video of me revving the car in neutral, when I rev up the engine over 3.5k in gear, the car stops accelerating and stutters, I believe that this is due to a bad MAF.
 
I'm having issues with the car I bought recently, my 98 GSX AUTO, where the car does not like to release boost, I have a greedy type-s bov, and the stock turbo and internal wastegate, some vacuum lines may not be properly connected or I may be leaking boost. All I know is that the car is dumping fuel, my boost gauge does not increase it just sits and remains idle at 0, although it sounds and feels like its building boost. I have attached a video of me revving the car in neutral, when I rev up the engine over 3.5k in gear, the car stops accelerating and stutters, I believe that this is due to a bad MAF.
Stock boost gauge?
 
Does the gauge move at all up or down? Did this just start? No video posted
When engine turns over boost gauge moves up to 0 from resting position but then does not increase with revs, car has had the problem since I bought it two days ago, also I apologize for no video being posted, this reply should have a video posted to it.

Google Photos Link To Video:
 
the car is having Overboosting issues and the BOV is not releasing as much boost as it should be

You are confused, the BOV is not to control boost pressure unless you built the car in that way instead of using a wastegate. Even if you would block off the BOV, it wouldn't affect the MAX boost pressure, it's just it wouldn't be friendly for turbo.

So usually the BOV is not related to the overshooting issue. Overshooting is caused by something else, such as wastegate is stuck, boost controller is not set properly, you have a high pressure spring in the wastegate, boost creep etc.

To me it sounds like the car has multiple issues.
Like Marty said above you got a nice car, so just give a good maintenance first, fix all issues one by one. A turbocharged engine would be easily destroyed by a tiny issue.

but then does not increase with revs

Because you don't build the boost in neutral.

BTW, you can upload a video by clicking "Add Video". No need to link your own.
 
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You also have a lot of misinformation in your post. Please post some direct questions and we will try to help. You have multiple problems for sure.
 
Tell us everything you know. Pics please. Car does not sound right.

Alright, so previous owner said the car was over boosting but failed to elaborate further. The car is currently getting very bad fuel economy, I’m getting somewhere near 10 mpg.

I believe the MAF sensor is bad as my car is having very similiar issues to what other people have reported on these forums having with a bad MAF, such as poor fuel economy, and bad stuttering and no acceleration past ~3.5k rpms in any gear.

It has a very bad exhaust leak, there is a hole in the side of the cat. The car has stock turbo and wastegate, stock downpipe, with an apexi catback, ceddy mods 1v9cb ROM in the factory ECU, Greddy intercooler pipes, and type S blow off valve. The blow off valve currently has stripped threads on the inside of the adjustment shaft.

I don’t know much about my boost issue because I cannot accelerate past 3.5k.

There was a vacuum hose port on the intake manifold that was plugged over that says it’s the return assist on a diagram I found, that feeds pressure back to help open the BOV. The first picture is a vacuum hose I found in the car that fits perfectly between the intake manifold and BOV. The second image shows my valve cover leaking some oil, I believe there’s some damage on the top because there are some small welds on the top of the cover, I have already ordered a new one and will replace it when I have it.

Oil pressure gauge is reading low. I have attached a photo showing where my oil pressure gauge usually reads while the car is on.

I can’t show you exactly because last night, I came to a stop at a red light on my way back home from the gas station and found out the previous owner had deleted the battery tie down and installed a strut brace which causes the positive terminal to ground itself to the strut bar and shut the car off. I pushed it off into a parking lot and towed it back home as I was less than a mile away. Got up this morning replaced the battery and the car still doesn’t start.

I have a theory it’s a bad starter or relay to the starter as the solenoid moves but it doesn’t fully engage the starter motor.

Attached below there is a picture I took of the battery and strut bar. Also below, I have attached a video of what happens when you press the pedal and push the motor past 3.5k rpms.

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Alright so previous owner said the car was over boosting but failed to elaborate further, car is currently getting very bad fuel economy, I’m getting somewhere near 10mpgs, I believe the MAF sensor is bad
do not assume without testing. I doubt your maf is bad or at least it wouldnt be my first choice to look at.
as my car is having very similiar issues people have reported on these forums having with a bad MAF, such as poor fuel economy, and bad stuttering and no acceleration past ~3.5k rpms in any gear, it has a very bad exhaust leak, there is a hole in the side of the cat, car has stock turbo and wastegate, stock downpipe, with an apexi catback, ceddymods 1v9cb rom on factory ecu
you need to know all that was done for sure. If you can't I would go back to stock to work out the issues.
, Greddy intercooler pipes, and type s blow off valve, blow off valve currently has stripped threads on the inside of the adjustment shaft, but I don’t know much about my boost issue because I cannot accelerate past 3.5k, there was a vacuum hose port on the intake manifold that was plugged over that says it’s the return assist on a diagram I found, that feeds pressure back to help open the bov,
bov needs a vacuum hose and the outlet needs to return to the inlet before the turbo.
the first picture is a vacuum hose I found in the car that fits perfectly between the intake manifold and bov, the second image shows my valve cover leaking some oil, I believe there’s some damage on the top because there are som small welds on the top of the cover, I have already ordered a new one and will replace it when I have it. Oil pressure gauge is reading low I have attached a photo showing where my oil pressure gauge usually reads while the car is on,
change the oil immediately.. it is likely fuel saturated.
I can’t show you exactly my car because last night I came to a stop at a red light on my way back home from the gas station and found out the previous owner had deleted the battery tie down and installed a strut brace which causes the positive terminal to ground itself to the strut.
Take the bar off for now.
bar and shut the car off, I pushed it off into a parking lot and towed it back home as I was less than a mile away. Got up this morning replaced the battery and the car still doesn’t start, I have a theory it’s a bad starter or relay to the starter as the solenoid moves but it doesn’t fully engage the starter motor.
Check and make sure you attached all the grounds when you replaced battery.
Attached below there is a picture I took of the battery and strut bar. Also below, I have attached a video of what happens when you press the pedal and push the motor past 3.5k rpms.https://www.youtube.com/watch?v=sE_UnXYmuvc

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1- Ceddy mods probably disabled the boost gauge and its operating as it should depending on how it's configured. It's also likely your free revving is hitting a 3500 rpm limit set in ceddy. You'll need a tactrix cable to verify any of this- id ignore it for now.
2- If the yellow indication on your oil pressure gauge is where it's sitting that is fine and normal. The gauge is a worthless tool for troubleshooting as is the factory boost gauge, but so long as it moves off the bottom line and the oil pressure dummy light isn't on we can assume you have enough oil pressure.
3- When your battery hit the strut bar it probably wiped a few fuses out with it. The big 100amp fuse in the fuse box would be the first fuse I'd look at it, dont start throwing parts at it without confirming.
4- boost leak test this car and change the oil before going further, likely it'll solve many issues you're having
5- check your trans fluid, if the trans is slipping you've got bigger issues already.
6- can we compile an organized list of concerns/issues with the car? It's impossible to help you when I can't even comprehend half of what the car is doing from the brick of scattered information you have posted.
 
The valve covers are very prone to cracking when not torqued properly.
Most has been stated but the main fuse that blew when it grounded the battery(most likely)
I picked up a new Valve cover yesterday, and I was able to diagnose why the car doesn’t start, when I grounded my battery something happened and caused the ground for the starter to go bad. When using a piece of new wire to properly ground the starter the car fires right up first time.
 
Valve cover sounds like the least of your problems. Are you sure you didn't miss a ground when reinstalling battery? If you installed another one I would hope it is the proper gauge.
 
So I've installed a new battery, and Diagnosed why the car doesn't start, the ground to the starter got messed up in some way or another when the battery was grounded out, also, my valve cover was leaking oil profusely and I got a good deal on a new one. I have taken the advice of several people on here and made a checklist of problems and things that need to be done to the car, if anyone has any input on any of the problems feel free to leave a comment on the spreadsheet.
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1- Ceddy mods probably disabled the boost gauge and its operating as it should depending on how it's configured. It's also likely your free revving is hitting a 3500 rpm limit set in ceddy. You'll need a tactrix cable to verify any of this- id ignore it for now.
2- If the yellow indication on your oil pressure gauge is where it's sitting that is fine and normal. The gauge is a worthless tool for troubleshooting as is the factory boost gauge, but so long as it moves off the bottom line and the oil pressure dummy light isn't on we can assume you have enough oil pressure.
3- When your battery hit the strut bar it probably wiped a few fuses out with it. The big 100amp fuse in the fuse box would be the first fuse I'd look at it, dont start throwing parts at it without confirming.
4- boost leak test this car and change the oil before going further, likely it'll solve many issues you're having
5- check your trans fluid, if the trans is slipping you've got bigger issues already.
6- can we compile an organized list of concerns/issues with the car? It's impossible to help you when I can't even comprehend half of what the car is doing from the brick of scattered information you have posted.
Thank you for all the advice, The spreadsheet should act as an organized list of issues going forward.
 
I want to endorse the "don't throw parts at it" with one exception: With a Mitsubishi auto transmission that you think might be slipping, park that car until you change the transmission fluid. Use ONLY Mitsubishi ATF SP III or the MOPAR equivalent for which I don't remember the name.

This fluid is lower viscosity than any other modern fluid. That means when the stack of clutch plates in a Mitsu transmission is squashed together, the fluid gets out of the way and there's only enough slip during engagement to cushion the shock.

If another fluid is used the transmission will slip and it'll shortly wear out those clutches. And this bit of knowledge seems rare, even among people like transmission rebuilders who ought to know better. No kidding -- of four mitsu automatics I own, one got rebuilt and filled with the wrong fluid: I caught that on the six mile drive home and changed it immediately, one got the fluid changed to the wrong stuff by the retired Mitsubishi tech I bought the car from -- I had him change it before we drove it home, and one -- my GS-T -- had poor but noticeable shifts that improved dramatically when the fluid was changed. I'm guessing someone added a quart or so of the wrong stuff.

Starting off on level ground with a gentle throttle you should be able to count all three shifts as you accelerate. No squishiness, no over-reving during the shift.

The bad news is these transmissions aren't easily changed. Capacity is around 7 quarts but you cannot normally drain more than 3.5 or so, meaning you have to change a bunch of times (with maybe 10 miles driving in between) to get anything like a clean job.

Where you are now I'd get 8 quarts in hand, check the fluid level as usual, and put the front up on ramps at least overnight. Then drain as much as you can -- there are two plugs, different sizes I think. Measure what you get out, put the plugs back in, and add that amount of new fluid plus enough to correct if the level was down when checked. Test drive: If you had the wrong fluid (a) shifts will be much better right away, and (b) shifts will then get worse again as more of the 'bad' fluid returns to the transmission pan and is pumped out to the clutches instead of the 'good' fluid you just put in.

If you get this pattern you can take heart: The transmission may be okay although you must change the fluid again at least two more times to get rid of enough of the wrong stuff.

For example if you get 3.5 quarts drained and put the same back you've replaced half the bad stuff. Now you drive the car enough to mix the fluid and replace half again: You've gotten rid of 3/4 of the bad. Repeating will get you to 7/8.

Unfortunately the %#$@ wrong fluid has also soaked into the clutch plates. After three changes I drive it for 1000 miles or so and then change it again.

If the first change of fluid doesn't make any difference then you probably have a worn out transmission and pouring more fluid through it won't help.

This is tedious and at something like $12/quart last time I did it very expensive. If there is a simpler way I'd sure like to hear it.

On an older transmission the check valves that prevent drain-back between drives may be leaky. In that case the transmission won't shift right when you start rolling after sitting overnight unless you shift through all the gears a couple of times first to refill everything. The good news is that if you let that car sit ready to dump for a couple of days you might get 5 or even 6 quarts out meaning you only need to change a couple of times to get rid of nearly all the wrong fluid.

If the transmission is slipping your gas mileage will be terrible.

Good luck with it!

Edit: I've had my '95 GS-T seven months I think and its list has about 75 items, about half corrected and nearly all the rest at least partially done. What makes the work especially slow is that nearly all 90's DSM have been worked on by less than highly skilled people and you will find layers of issues so as each entry on your list is tackled you will fix things and discover other things -- my "A/C does not work" turned into five separate problems and only after fixing them all does the car get cool.

I agree with the comment to get back as close to stock as you can. When it runs well in that condition then you can consider which mods you want and do them in an orderly way.

It really is a beautiful car. Just pace yourself and try to enjoy the repairs. It's a lot of fun driving a machine you've made work properly.
 
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You seriously need to prioritize the repairs. Not running right and the transmission should be number 1.

Do not buy MAF cleaner and attempt to clean the MAF. We don't have the cleanable type. The cans will even say specifically not to use them on Karman vortex sensors which is what we have.

Basic diagnosis of baro and temp sensors will be all you can do. Boost leak test the car. This stuff has to be checked and problems fixed or you're gonna chase your tail or worse damage something on the car.
 
I want to endorse the "don't throw parts at it" with one exception: With a Mitsubishi auto transmission that you think might be slipping, park that car until you change the transmission fluid. Use ONLY Mitsubishi ATF SP III or the MOPAR equivalent for which I don't remember the name.

This fluid is lower viscosity than any other modern fluid. That means when the stack of clutch plates in a Mitsu transmission is squashed together, the fluid gets out of the way and there's only enough slip during engagement to cushion the shock.

If another fluid is used the transmission will slip and it'll shortly wear out those clutches. And this bit of knowledge seems rare, even among people like transmission rebuilders who ought to know better. No kidding -- of four mitsu automatics I own, one got rebuilt and filled with the wrong fluid: I caught that on the six mile drive home and changed it immediately, one got the fluid changed to the wrong stuff by the retired Mitsubishi tech I bought the car from -- I had him change it before we drove it home, and one -- my GS-T -- had poor but noticeable shifts that improved dramatically when the fluid was changed. I'm guessing someone added a quart or so of the wrong stuff.

Starting off on level ground with a gentle throttle you should be able to count all three shifts as you accelerate. No squishiness, no over-reving during the shift.

The bad news is these transmissions aren't easily changed. Capacity is around 7 quarts but you cannot normally drain more than 3.5 or so, meaning you have to change a bunch of times (with maybe 10 miles driving in between) to get anything like a clean job.

Where you are now I'd get 8 quarts in hand, check the fluid level as usual, and put the front up on ramps at least overnight. Then drain as much as you can -- there are two plugs, different sizes I think. Measure what you get out, put the plugs back in, and add that amount of new fluid plus enough to correct if the level was down when checked. Test drive: If you had the wrong fluid (a) shifts will be much better right away, and (b) shifts will then get worse again as more of the 'bad' fluid returns to the transmission pan and is pumped out to the clutches instead of the 'good' fluid you just put in.

If you get this pattern you can take heart: The transmission may be okay although you must change the fluid again at least two more times to get rid of enough of the wrong stuff.

For example if you get 3.5 quarts drained and put the same back you've replaced half the bad stuff. Now you drive the car enough to mix the fluid and replace half again: You've gotten rid of 3/4 of the bad. Repeating will get you to 7/8.

Unfortunately the %#$@ wrong fluid has also soaked into the clutch plates. After three changes I drive it for 1000 miles or so and then change it again.

If the first change of fluid doesn't make any difference then you probably have a worn out transmission and pouring more fluid through it won't help.

This is tedious and at something like $12/quart last time I did it very expensive. If there is a simpler way I'd sure like to hear it.

On an older transmission the check valves that prevent drain-back between drives may be leaky. In that case the transmission won't shift right when you start rolling after sitting overnight unless you shift through all the gears a couple of times first to refill everything. The good news is that if you let that car sit ready to dump for a couple of days you might get 5 or even 6 quarts out meaning you only need to change a couple of times to get rid of nearly all the wrong fluid.

If the transmission is slipping your gas mileage will be terrible.

Good luck with it!

Edit: I've had my '95 GS-T seven months I think and its list has about 75 items, about half corrected and nearly all the rest at least partially done. What makes the work especially slow is that nearly all 90's DSM have been worked on by less than highly skilled people and you will find layers of issues so as each entry on your list is tackled you will fix things and discover other things -- my "A/C does not work" turned into five separate problems and only after fixing them all does the car get cool.

I agree with the comment to get back as close to stock as you can. When it runs well in that condition then you can consider which mods you want and do them in an orderly way.

It really is a beautiful car. Just pace yourself and try to enjoy the repairs. It's a lot of fun driving a machine you've made work properly.
My issue with getting the car to run stock is that I do not have any of the stock parts. I purchased the car as is, however after digging with the car I no longer believe the transmission is the issue however I will check out the fluid soon, does the car need to be up to temp to check out the trans fluid?
 
Okay so should I just replace the MAF?

Previous owner says that the car did not do the stuttering at 3500rpms that it does now, he also said the boost gauge worked, then the car sat, and I believe in that time period when the car sat the MAF has gone bad.

I’ve been told that the Boost gauge measures air flow from the MAF, and I’ve seen some other people on the DSMTuners forums talk about stuttering at 3k rpms and the end diagnosis was a bad MAF, so with my current knowledge, my best guess at what’s wrong with my car would be a bad MAF sensor. So I am going to replace it, and if the cars condition improves then yay the car works, and if not then I will just return the new sensor, it’s that easy.

And a BAD MAF combined with a funky ECU tune and over boosting would help explain my fuel dumping issue.
 
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