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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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Okay so should I just replace the MAF.
No.
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.
And what have you done to diagnose this that tells you this? You should consider that the previous owner is lying to you.
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.
You are assuming a great deal. You also will not be able to return it. Throwing parts at a car is a poor and very expensive way to diagnose.
And a BAD MAF combined with a funky ECU tune and over boosting would help explain my fuel dumping issue.
You are again assuming. Without knowledge of exactly ceddymods is or isn't doing you have no way to know. You would be better off with a stock ecu and stock injectors for diagnostic purposes unless you know what mods there are for sure and how to deal with them.

This board is a collective 20 years and many member with 30 plus years experience. You will chase your tail. Even a 25$ blue tooth dongle and a copy of torque pro would be better than the guessing you're doing now.

It's your car do what you like but we are trying to help you.

Let me start a list
Do you know what size injector you have?
Do you know exactly what's been done to the ecu and how those mods affect boost gauge output and for what purpose?
Have you tested and addressed any leaks?
Is the bov recirculated to the intake?
Have you tested the bov to see if it's working?
Have you checked turbo for excess play both axially and radially?
Do you have a check engine light?
The car sounds very weird, do you know why?

These are the basic diagnostic questions that should be asked of anybody. Find the problem first, not throw possible solutions at it.

If you're confused by any of these questions ask and/or search.

You can throw parts at it all you want but if you want to understand and learn the car please follow the advice given so far. Look at the stuff we have cited and get back with us. If it were my car I would not drive it. I hope you aren't.
 
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?
this is one time I would advocate throwing parts at it. Stock injectors and ecu are likely cheaply secured if not borrowed. Can you verify what it has? At least pull the ecu and see if it's a black box. For all you know that's a lie also.
 
I'll add this to the mix also.

5-steps to Problem Solving
  • Define the problem.
  • Gather information.
  • Generate possible solutions.
  • Evaluate ideas and then choose one.
  • Evaluate.
In this case (and many car issues) one problem may be related to others. From experience the car does not sound right. How this piece of information plays out is yet to be determined.
The gather information piece may be your most important. Gather what you KNOW. Not what you are guessing at. Some things will be an educated guess and not 100% objective and sometimes that's the way it has to be but a 100% guess is a poor way to solve a problem. Try and keep the subjective stuff to a minimum.
 
Do you know what size injector you have?
Do you know exactly what's been done to the ecu and how those mods affect boost gauge output and for what purpose?
Have you tested and addressed any leaks?
Is the bov recirculated to the intake?
Have you tested the bov to see if it's working?
Have you checked turbo for excess play both axially and radially?
Do you have a check engine light?
The car sounds very weird, do you know why?
I believe the car has stock injectors, but I will verify and reply soon.
I do not but I know someone with a tatrix cable and am going to take a look into my ECU soon.
I have not tested for boost leaks yet, however, after tracing vacuum lines I found out that the previous owner's solution to over-boosting was to block off the wastegate from the solenoid, have since unblocked it and routed it back to where it needs to be.
Yes, bov is recirculated into the intake.
No, but that's what I plan to do today, I'm also going to take the bov off the car, and clean the internals to ensure nothing internally is seized from the car sitting.
Also no I haven't checked for axial or radial play in the turbo, but I will add that to my spreadsheet and check that before the car is driven.
I do not have a check engine light on, it turned on after I grounded my battery so I know the light works but it's currently not throwing any codes, I also have an OBDII reader that will even chart and log data based on sensor readings however my OBDII port is not working properly if anyone has any info on this I would love to hear it. I took a volt meter and tested and the power supply in the OBDII has a constant 12 volts as it should be but that's as far as I've investigated it.
My only guess as to why the car would sound this weird would be the large hole in the cat in the downpipe, this car probably has no cats left and has a major exhaust leak exited from the cat in the downpipe as there is a hole in the side of it.

Also took the MAF out of the car and cleaned it out just with air, and after plugging it back in, the car will now rev back out past 3.5k.
Also turns out the wire I was fiddling with, with the starter was the signal wire and not the ground wire, the signal wire to the starter had a very weak connection and that has since been tightened up so now the car starts consistently.

Also just a note, I have not been driving the car, the only time the car has been driven other than bringing it home, was last night to test if the MAF sensor had fixed the "imaginary rev limiter" and it has.
 
I believe the car has stock injectors, but I will verify and reply soon.
I do not but I know someone with a tatrix cable and am going to take a look into my ECU soon.
I have not tested for boost leaks yet, however, after tracing vacuum lines I found out that the previous owner's solution to over-boosting was to block off the wastegate from the solenoid, have since unblocked it and routed it back to where it needs to be.
Thats not how that works. Boost solenoid only job is to cutoff a factory "leak" in the line and it lowers boost. Not using the solenoid will give you whatever boost the spring in the actuator will provide unless you install a manual boost controller
Yes, bov is recirculated into the intake.
No, but that's what I plan to do today, I'm also going to take the bov off the car, and clean the internals to ensure nothing internally is seized from the car sitting.
What I mean is apply a vacuum to it and make sure the valve moves.
Also no I haven't checked for axial or radial play in the turbo, but I will add that to my spreadsheet and check that before the car is driven.
I do not have a check engine light on, it turned on after I grounded my battery so I know the light works but it's currently not throwing any codes, I also have an OBDII reader that will even chart and log data based on sensor readings however my OBDII port is not working properly if anyone has any info on this I would love to hear it. I took a volt meter and tested and the power supply in the OBDII has a constant 12 volts as it should be but that's as far as I've investigated it.
You might try another reader.
My only guess as to why the car would sound this weird would be the large hole in the cat in the downpipe, this car probably has no cats left and has a major exhaust leak exited from the cat in the downpipe as there is a hole in the side of it.
put something over the hole temporarily. Even a coke can wired over it might be able to help identify the sound. For what it's worth I don't think that's it.
Also took the MAF out of the car and cleaned it out just with air, and after plugging it back in, the car will now rev back out past 3.5k.
My guess it was the connection itself was not good. Either way you seemed to have solved one problem. Did anything else change? The sound of the car? Black smoke?
Also turns out the wire I was fiddling with, with the starter was the signal wire and not the ground wire, the signal wire to the starter had a very weak connection and that has since been tightened up so now the car starts consistently.
Ground wires for the starter circuit are large and go directly to the battery.
Also just a note, I have not been driving the car, the only time the car has been driven other than bringing it home, was last night to test if the MAF sensor had fixed the "imaginary rev limiter" and it has.
I would imagine idle, rev and normal driving characteristics have changed now. Did you try it?
 
I would imagine idle, rev and normal driving characteristics have changed now. Did you try it?
Oh it absolutely did feels like a completely different car. If I had to guess this could have *improved but not solved* my fuel dumping issues but I would have to drive the car quite a bit to see any difference there and I’d rather still hold off on that. I’m gonna try and change the oil if weather permits today, but I’m going to at least get the bov off and apart to see if the O-Ring in it is bad, and to check if the internals are seized.
I took a look at the Car Fax on this car and back in 2013 the car had 162,543 miles one it, and now here 9 years later it has only been driven 7,888 miles in the past 9 years…
 
I have completely and reliably diagnosed a lot of the issues I have been having. Check out my checklist and let me know if you guys have any comments on anything I could be doing better. The car runs and drives now very smoothly, drove the car about 20 miles today and held very consistent oil pressure and engine temperature the entire time, the car seems to be fine, everything is running very nice and smooth other than the transmission, it feels very clunky downshifting into 1st, and shifting into reverse, I checked the transmission fluid while the car was up to temp, and it is reading overfilled, I need to get some of the fluid out of there but I am unsure how to do that yet. Also due to the holidays this will be the last time I'm probably active on the forums until next week, I also won't resume work on the car until Monday. Thank you guys for all your help.

Checklist Reupload
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Apparently you're not driving car. I suspect your oil is fuel diluted. Smell it. Change it asap before driving again. Thinned oil destroys bearings.

I'm not following the wastegate hose correction. Disconnecting a line will not prevent overboost. Quite the opposite.
 
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,
I've got the same issue but less of it I think. In that case 'as close to stock as possible' may not be very close.
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?
Check how it shifts. If starting off on level ground at moderate throttle it accelerates steadily and you can feel each of the three upshifts without any overreving as it changes gears then the chances are it's fine.

Shifts will be obvious on the tachometer.

With the wrong fluid you may be unable to feel any shifts at all, at least they will be squishy, revs will vary a lot with throttle even though car speed isn't changing, acceleration will be slow, and gas mileage will be terrible. Mileage should be around 18 locally, 25 or better highway -- ballpark figures from 7 months with my '95 GS-T auto.

Am I the only one here who has driven a 50's Buick Dynaflow? That's what a 'wrong fluid' transmission reminds me of. Mitsubishi automatics should shift about like a very skillfully operated manual transmission -- you can feel the shifts, but just barely.

Also look at the fluid on the dipstick -- if it's clearly red to pink and looks clean it's okay. If it's brown or contains particles it is old and needs a change.

I like to change the fluid anyway on a newly-purchased car but if money's tight then no.
 
it feels very clunky downshifting into 1st, and shifting into reverse, I checked the transmission fluid while the car was up to temp, and it is reading overfilled, I need to get some of the fluid out of there but I am unsure how to do that yet.
'Clunk' when shifting from neutral into D or R is normal unless it feels extreme -- like "I hope that didn't break anything!". Shifts between the three forward gears while standing still should be imperceptible.

To take out some fluid get the front up a bit -- Wal-Mart's plastic ramps are what I use. The transmission is on the passenger side, the pan flange is slanted down toward the rear of the car and there is a 17mm drain plug on the backside. Start it with a wrench then carefully back it out until you can drain a cup full or two into a clean container and slap that plug back in again. Get the car down off the ramps and look at the level again.

You will get oil all over your hand and you don't want to drop that plug so this is not a job to do when the transmission is hot.

These transmissions aren't really easy to check. Be sure to follow the directions about shifting into all the gears and checking while running in neutral. Check more than once, wiping the dipstick dry in between and looking at the level on both sides -- oil splashes around down there and can confuse the reading. If there's a disagreement, take the lower reading -- the higher one is a splash.

It's okay for it to be a little high -- some people actually recommend that.

Take a strong flashlight and spend a few minutes looking around while you're under there. Lots of interesting stuff even if it's all perfectly normal -- which is very rarely the case on my 'new' cars!

Be sure to follow Pauleyman's advice (above) about your oil. If the mileage is as bad as it appeared to be and flames aren't shooting out your tailpipe and the transmission is okay then that extra gas is likely in the oil and you do not want to drive the car without at least changing it.

Your list looks like a good start. These cars are supposed to have group 86 batteries but many have 26's. The case size is near identical but the terminals are on the other side. Either seems to work. I would look for a used hold down -- eBay is good for stuff like that, also there are DSM tuners sponsors who have such parts. And there are the classifieds.

A search engine search for 'mitsubishi parts' will turn up many sellers with 'mitsubishi' and 'parts' in the address: These are dealer parts departments looking for extra sales and they give you access to the Mitsu parts catalog which you can use to find part numbers. They may actually have your part, although 'what they actually have' is less than 'what the catalog says they have.' But take that number and search again -- it's surprising how often you find a source for even uncommon items.

Watch the shipping for such dealers.

Auto parts stores may sell generic battery hold downs that'll solve the safety problem in a hurry and if they don't you can buy the hold down bolts there (they do have those) and make a crossbar from a piece of stock from a hardware store.

Edit: This would be a good bet:

 
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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.
I would not replace the MAF without more data. Do you have any diagnostic trouble codes set? There's a code for a bad MAF -- P0100 -- and the checks for 'is it okay' seem to pretty well cover the likely failures. If you don't have that code the chances are you don't have that problem.

Of course you can replace it just to find out if that's the problem if you're sure they'll take it back if you don't need it -- some electronic parts (this is ...) aren't returnable if they've been installed.

It would be good to hear some more about that 'stuttering at 3500 RPM.' Does it happen at that RPM regardless of load? In different gears?

"Somebody on another list had my symptom and his problem was ..." isn't very reliable -- there are too many different causes that could yield a symptom that sounds like yours. Think of all the problems that could cause "he had trouble walking" and you'll see the issue.

The boost gauge is connected to the intake plenum and measures the vacuum or pressure there -- it's just a pressure gauge hooked to the plenum by a small hose. Air to the plenum comes through the MAF (which is mounted on the stock air filter assembly) but the boost reading is affected by both the turbo and the throttle valve.
 
I fixed my OBDII port and managed to read this code.
P0120 Means something is wrong either with the closed throttle position switch or with the throttle position sensor -- basically the ECM has detected that the story it's getting has a conflict. I would first check the switch -- that it's closed when the throttle is closed and opens when the throttle opens a bit. Then check that the resistance of the throttle position sensor meets the specs.

The engine's definitely not going to run right with conflicting facts about the throttle position!
 
I'll bet on the switch. Post some pictures of the engine please. Particularly the throttle body area.
Sorry for such a late response, I ended up getting the code to go away and fixed the issues with a new TPS Sensor, I had bought two tps sensors and the first one was defective when I received it so it confused me. Parts store TPS sensors suck 👎
 
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