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Common Problems and Fixes

Also be sure to check the SE-R FAQ.

The SE-R Mailing list Home Page also has some selected TSBs.

TSB and Safety Information

Common Problems:

PROBLEM: 5th gear pops out while driving.

Affects:  Sentra SE-R, NX2000

More information is available here.

PROBLEM: Erratic Idle and jumping idle, some other symtoms are also: sluggish performance, real bad mileage, injector leak malfunction code, o2 sensor voltage stuck at 800 mv or so.

Affects: Sentra SE-R, NX2000,

Try doing a MAF Sensor Grounding.

Also look at solutions to the Low Gas Mileage problem.

red_triangle.gif (202 bytes) Comments by Vito Biundo

One thing you may want to check is that the idle was set correctly.   The AAC valve is supposed to regulate the flow of air at idle in order to keep the engine at ~800 rpm.  My 93.5 G20 used to have a quirk that disconnecting the TPS would not fully close the AAC valve as it should.  I would attempt to adjust the idle per FSM instructions, but turning the idle adjust screw would not affect the idle at all because the AAC valve was still operating and keeping the idle at 750rpm.  Sometime after my 60k tune-up I reset the computer which seemed to have eliminated this quirk.

The best way to see if you have this problem is to warm the car up, turn the engine off, disconnect the TPS, and start the car back up.  Hopefully, the idle will be at about 750rpm.  If so, disconnect the AAC valve while the car is still running.  If the idle stays constant, your idle is set correctly.  If the engine stalls or the rpm's drop, your idle may be set incorrectly.

Another cause of poor idle is exhaust gas recirculating back into your intake.  A faulty EGR is the most widely known culprit but there is another source that can potentially choke your engine, the PAIR(AIV). This is that EGR looking device mounted on the front of the engine close to the radiator.  It's whole purpose is to allow fresh air into the exhaust stream at idle.  On a stock set-up it takes this air from the intake just past the air filter.  The PAIR(AIV) has reed valves in it that are supposed to allow air to be sucked into the exhaust stream and prevent exhaust from flowing back into the intake.  Unfortunately, the reed valves on my unit are warped due to the heat of the engine and don't prevent backflow of exhaust gas.

If you want to check the PAIR(AIV), open your filter box while the car is idling.  There should be a port on the left hand side of the upper half of the box.  You should be able to feel a vacuum on that port if it's functioning right.   If not, you can feel puffs of air coming out of the port, and it will sound just like an exhaust leak.

red_triangle.gif (202 bytes) Comments by Dan Thompson

Whew! All that to fix the idle? You must be as anal retentive as me! :)

I can think of 3 other things that may be causing your problem.

First, you may have dirty injectors. The '91-'93 high port head is very sensitive to airflow velocity and injector spray pattern at low rpms due to the length of the intake "runner" within the head. A partially clogged injector or one with spray pattern problems won't "atomize" the fuel properly, causing a "non-homogenous" mixture within the combustion chamber. It could also cause fuel to hit the port wall, meaning the fuel will "dribble" into the combustion chamber rather than being carried in with the air.

Second, your Throttle Position Sensor may be out of adjustment. You can see the procedure in If you don't have internet access, I can send the procedure to you.

Third, your throttle body may not be clean. Now I know you said you cleaned it, but did you *clean* it? My throttle body had a "ridge" of build-up where the throttle plate sits when it's closed. Carb cleaner wouldn't even touch it. I had to use rubbing compound to get rid of the stuff (Note: this was done with the TB off the car). I also found the same deposits around the edge of the throttle plate and had to use the same procedure to get rid of them. Finally, the back of the throttle plate had a build-up of a hardened, gray clay-like material on it. It took rubbing compound to remove that too. Before I cleaned the TB, if I held it up to the light, I could only see pinpricks of light between the throttle plate and the wall of the TB. After cleaning it, I could see light (the plate doesn't completely close off the TB, there's a **small** amount of clearance) all the way around. I imagine a small amount of air is drawn in around the plate by design. The build-ups decrease or eliminate this, making the car rely completely on the IACV for idle airflow.

BTW, I removed the throttle plate from the throttle body to do the cleaning. It's only held in with two screws. Remove them, open the throttle completely and push the plate out toward the back of the throttle body (ONLY IF THE TB IS OFF THE CAR!!!). I found the screws extended down into the throat of the throat of the TB, so I found some shorter ones that didn't extend beyond the throttle shaft and used them in place of the originals. I used a bit of Loktite to make sure they don't back out and get ingested by the engine.

Unfortunately, the throttle body isn't on the car (spare), so I can't tell you if it made a difference with the idle or not.

PROBLEM: The inside edge of the front tires are worn, abnormal wear of the tires..

Affects: 200SX SE-R

This problem is caused by chaining the car down too tight when transporting your 200SX, and it causes excessive toe-out. Have Nissan re-align the front wheels.  NOTE: Nissan gives you one free alignment up to 12,000 miles or 1 year, whichever comes first.

Here's a before and after of one of the guys alignments specs:

                      Before                    After

Front            Left      Right          Left         Right
Camber          -0.9 deg  -0.7 deg       -0.9 deg     -0.7 deg
Cross Camber          -0.2 deg                  -0.3 deg
Caster           2.3 deg   1.1 deg        1.3 deg      1.1 deg
Cross Caster           0.2 deg                   0.2 deg
Toe             -0.23"    -0.16"          0.04"        0.05"
Total Toe             -0.39"                     0.09"
Set Back              -0.13 deg                 -0.13 deg

Camber          -1.0 deg  -1.2 deg       -1.0 deg     -1.1 deg
Toe              0.03"     0.01"          0.02"       0.01"
Total Toe              0.04"                    0.03"
Thrust Angle           0.02 deg                 0.02 deg

PROBLEM: You get a check Engine Light.

Affects: 200SX SE-R 5speeds only

You get a check engine light on the 200SX SE-R 5speed that doesn't go away. Checking the error code reveals that the EGR-BPT (backpressure valve) failed (Code 36). Replacing the EGT-BPT  doesn't make it go away.

Have the EGR tube replaced. The original EGR tube diameter was 10mm letting too much EGR in, setting off the check engine light. Nissan changed the tube to 8mm which seems to resolve this problem.

PROBLEM: You get a sort of a moaning, grinding screech.   Others think it sounds like belt like squeal noise that happens during starting the car.

Affects: 200SX SE-R, Sentra SE-R, NX2000

red_triangle.gif (202 bytes) Comments by Wayne Cox

Didn't get any responses on my starter squeal inquiry; but I did dig up some interesting info on SR20 starters. My question was if the squeal was only on early production classics, or if any NXen or 200s had it.

I found this in the parts-microfiche, prices are from

SE-R 1991-92 23300-63J00 Hitachi $201
SE-R 1993- 23300-63J01 Hitachi $177
NX2000 1991- 23300-63J10 Mitsubishi $147

So it looks as if only the early production Hitachi starter may have been affected. The parts listing said the -63J01 was an alternate / revised part for the -63J00. So I don't know why the older one is available, esp at a higher price?! I assume the Mitsu starter is also compatible [it is, see Brad's comments below]; if so it's the cheapest and more reliable.

I think the brushes are the source of the noise. They are available cheaply, so I'm going to do a DIY rebuild on mine and see if that cures it.

red_triangle.gif (202 bytes) Wayne Cox further writes:

The starter noise is a high-pitched squeal, like a slipping belt, that occurs on start up. I tore my ['92 SE-R] starter apart and found two possible sources: the brushes, and what I'll call a "drive coupling."   The drive coupling is a one-way clutch that couples the motor to the pinion gear. When the motor spins, it hooks 100%. Turning the other direction, like when the engine starts and is suddenly spinning faster, it releases. I guess this prevents the starter from "over revving."

red_triangle.gif (202 bytes) Comments by Brad Woodworth

Well I got around to doing something about the infamous starter squeal. I removed the starter out of my '95 SE-R and found it to be a Hitachi unit. I replaced it with the Mitsubishi unit out of my wrecked NX. What was happening was that the bearing had loosened on the Hitachi causing it to have some play in the gear, thus the squeal. The design of the Mitsu doesn't allow this b/c it has a "hood" that houses the rod that the gear slides on preventing any side-to-side movement of the gear. The Hitachi's gear just slides out of the housing and is fully exposed allowing greater stress on the bearing. Voila! No more squealing.

PROBLEM: Water in your trunk.

Affects: Sentra SE-R, possibly NX2000

Comments by Marc Hernandez

Somebody wrote about water in the trunk and this is the reply.

It's actually coming from the taillights. Do this. Open up your trunk, and pull up both the carpet and the felt stuff off the rear of the car (that covers the taillights). Take a BIG cup of water, preferably a quart or more, and pour it in the runoff that sits around the trunk. At the top right corner. This runoff sits right off the edge of the top of the fender (sits under the crack between the trunk and fender). Water will run down this channel and over your taillights. But then you'll notice it runs *behind* your taillights. Look inside your trunk and if your poured enough water, it will be pooling up inside your trunk. If you don't see it there, look at the black goo that surrounds your taillights very carefully. There should be water dripping from it. There are two ways to deal with this:

1) Add more goo to the sealant around the taillights (harder)

2) Place silicone sealant in the crack behind the taillights making water flow OVER the light instead of behind it. (easy)

I chose option 2, and since it's clear silicone, you can't see it if you take your time and do a good job. Water runs over the light (you have to do the top, side, and the top right corner or it doesn't work right). Took me about 15 minutes total, and no more water in the trunk. :)

PROBLEM: Fuel pump failure, causing the car to be inoperable.

Affects: Sentra SE-R 91-93

Comments by Wayne Cox

Ok, here is more info from the bulletin:

All US built 1991 and 1992 Sentras (B13)
All US built 1993 Sentras through serial number 730388
  [the serial number is the trailing digits on your VIN plate]

"Nissan has assigned Campaign Number 93-U3005 to this Campaign"

Dealer Responsibility:
It is the Dealer's responsibility to make the correction listed in the Bulletin on each vehicle within the affected VIN range of this Campaign, except those that have had a fuel pump replaced after 1-1-1993, which enters the Service Department, regardless of where it was purchased.  This includes vehicles purchased from private parties or presented by transient (tourist) owners and vehicles in Dealer inventory (new or used).

The dealership can bill Nissan for parts and 0.7 hours of service time.

Two fuel pumps may have been used:  JECS brand, gold in color, no replacement needed;  Bosch [garbage] aluminum color - replace it.  Both have the manufacturer imprinted on the case as well.

If the Fuel Pump is a BOSCH type, remove and replace it with a new, countermeasure BOSCH pump, P/N 17042-Q5601BC.

PROBLEM: Engine noises (clatter) just after starting the car.

Affects: 200SX SE-R, Sentra SE-R, NX2000

> This sound is consistent in that it occurs whenever the car sits for a
> few hours...  at 32,000 miles, the tensioner should not be this bad.
>  Also, the sound completely disappears after a few seconds,
> and does not appear at WOT or idle.

Comments by Rick Zotz

The tensioner was revised during the '91-'94 model years, so I doubt this is your problem.  I would suspect either:  [Tensioner information here.]

- one or more bad hydraulic valve adjusters which aren't pumping up rapidly enough during startup, or

- high oil viscosity, which doesn't allow the oil to flow fast enough during cold starts, resulting in the same pump up problem in the valve adjusters. [Oil information here]

My valvetrain also makes some noise during startup, but none of the bad chain slap that prompted the tensioner change.

PROBLEM: Low gas mileage, 20mpg or lower

Affects: 200SX SE-R, NX2000, Sentra SE-R

Basically, there a two common things that can cause this problem, one is the oxygen sensor and the other is a dirty throttle body. [Info on cleaning the throttle body] Some people recommend replacing the oxygen sensor at 60K while others say about 100K.   So, if you have over 60K and are having problems with low gas mileage and are not driving a 100% city, then consider replacing the oxygen sensor.

Another cause of low gas mileage has been suggested by Dan Thompson: Dirty ignition wires. Refer to his comments below for an explanation.

Comments by Marc Hernandez

The sensor is about 64 dollars I believe.  I bought mine from Courtesy not too long ago and it made a huge increase (22MPG-30 HWY) in fuel mileage. The next increase came from cleaning out my throttle body, which gave me another increase of 3-4 MPG HWY.  I'm using HWY because that's a more steady rate of usage; I typically leadfoot around town and get about 22-24MPG in the city.

Comments by Rick Zotz

I replaced my car's O2 sensor near the 100K mark, and realized an improvement in throttle response (especially during the first five minutes of driving) and gas mileage - about 3-4 mpg.   Several other drivers here have done the same and have reported similar results.   The sensor is not cheap and it's a tight area to work in, but the benefits are definitely worth the effort.

red_triangle.gif (202 bytes) Comments by Dan Thompson

My car was suffering from poor economy and driveability. Economy was down to 20 or 21 mpg and the car would barely idle when cold. This was unusual for my car, as I typically got 30-32mpg with mixed driving.I tried the common fixes, such as new cap & rotor, new fuel filter and cleaning of the POP Charger, as well as installing new plugs. I have Magnecor wires (as well as an HKS Twin Power ignition), so changing them was unnecessary. No improvement.

I disconnected the HKS ignition, thinking that the spark may be too powerful for the A/F mixture with the recently installed JWT cams, as it would be less stratified at lower rpms with the JWT cams than with the stockers. My cold idle improved slightly, but fuel economy changed minimally (up to 21 or 22 mpg).

In the meantime, I purchased a copy of The Home Dyno software. An inductive pickup (from a timing light) hooked into a recording device is used to capture the ignition pulses, then the recording is transferred into a '.wav' file through a soundcard and ultimately processed by The Home Dyno software to give dyno results. While I was looking at my '.wav' files, I noticed a lot of "signal" being picked up from the other plug wires. In some cases, the ignition pulse from adjacent cylinders was as strong as the pulse for the measured cylinder!! 8-O I was getting cross-firing between cylinders!! This was probably being picked up as detonation by the ECU, which was retarding the timing as far as it would go (speculation).

I was certain that this cross-firing wasn't being caused by poor construction quality of the plug wires, as Magnecors are among the best you can buy (IMHO). I pulled the plug wires off the car and cleaned them with denatured alcohol (Magnecor suggests this solvent). [Ed: Alcohol may damage stock/rubber wires. Use a grease cutting soap solution instead.]  Boy were they dirty! I got all kinds of grease and grime off them, turning my rags and fingers brown as I cleaned. When I was done, the wires looked and felt like new again. After reinstalling the wires, cold idle was nearly normal and a new Home Dyno recording showed the cross-firing was eliminated, with minimal signs of adjacent cylinder ignition pulses showing up in the measured wire.

The next tank of gas, used for 50/50 highway/city driving, yielded 30.5 mpg. Throttle response was greatly improved and driveability was improved 100%. My theory is that the build-up of scrudge on the plug wire jackets allowed the ignition current to travel down the outside of the jacket, as well as through the conductor. The spark was then conducted, either in whole or in part, to an adjacent cylinder's wire when the resistance across that cylinder's plug was less than that of the plug the spark was intended for. BTW, I did check with the manager at the gas station and confirmed that they didn't switch from "winter" gas (oxygenated) to "summer" gas, so that didn't influence my economy. 

PROBLEM: Wiper failure

Affects: 200SX SE-R, and possibly others

I was driving home in the rain with the wipers on when all of a sudden they stopped working.  The motor seemed to be okay because it would make a jingling noise under the dash.  The dealer replaced the Wiper arm linkage.  This at 60K.

Comments by Arlyn Strano

This is a very common problem.  The wiper transmission is located under the cowling.  The area between the windshield and the hood.  You need to remove the cowling to find the linkage.  Most all cars have little plastic bushings that act as a washer located between the motor and the transmission linkage and then again between the transmission linkage and the wiper linkage.

Our service department carries a small assortment of the bushings in stock for exactly the circumstances you experienced.  The bushings are about $4 to $6 dollars at the dealer.

It is not a difficult job to do.  Should take about an hour or less.  Maybe something the do it yourselfer would consider as an ounce of prevention.

Submitted by Jared Isaacs

From CNNfn webpage, August 14, 1998: 12:16 p.m. ET

Title:  Nissan recalls 524,000 cars: Faulty windshield wipers in Sentras and 200SX cars need repair

CARSON, Calif. (Reuters) - Nissan Motor Corp. U.S.A., distributor of Nissan Motor Co. Ltd. vehicles in the United States, said Friday it has launched a voluntary safety recall of all 1995, 1996, 1997 and some 1998 Sentra and 200SX vehicles. The recall involves windshield wiper failure and affects about 524,000 vehicles, the company said. Water may enter a windshield wiper arm linkage ball joint, which could result in gradual wear over a period of time insde the joint, causing the wiper to stop working while in use, Nissan said. All repairs will be done at no charge to customers, the company said.

PROBLEM: Surge and hesitation between 1500 and 3000 rpm

Affects: All '91 - '93 SR20DE (Sentra SE-R, NX2000 and G20)

Engine bay (6108 bytes)
Red arrow: EGR valve
Yellow arrow: BPT valve
BPT tube (5645 bytes)
Green: BPT valve
Red: rubber tube

Yellow: End of metal tube
Orange: tube routing

If the usual tune-up procedure doesn't take care of the problem, disconnect the EGR valve and plug the vacuum hose leading to it from the BPT valve. Take the car out for a ride, making sure to drive in the same manner that typically causes the car to surge and hesitate. If the problem is no longer present, chances are good that you're experiencing the infamous "EGR Problem".

Remove both vacuum hoses from BPT (right-most disk shaped object behind valve cover). Remove the two philips screws on its top. Push the BPT back toward the firewall. You should see a rubber hose running between the bottom of the BPT and a metal tube. Remove the BPT and rubber hose from the metal tube and set them aside.

This metal tube is connected to the EGR passage and, ultimately, to the exhaust manifold. Exhaust manifold pressure, via this metal tube, operates the BPT valve which regulates the vacuum to, and the opening of, the EGR valve. The less exhaust manifold pressure - the more the BPT valve opens - the more the EGR valve opens. The more exhaust manifold pressure - the less the BPT valve opens - the less the EGR valve opens. Carbon may block this metal tube which causes the BPT to not operate properly (if at all) which causes the EGR valve to operate uncontrollably.

Wait until the car is cold, then spray some carb and choke cleaner into the metal tube to soften up the blockage. Used a stiff piece of wire (a long chunk of 8 gauge wire left over from the big car stereo install will do) to ream out the tube. (*Note: DO THIS WHEN THE CAR IS COLD!! Carb cleaner and a hot exhaust don't mix well.*) Take note of how far you have pushed the wire into the tube before you pull it out. Lay the wire along side the BPT tube to gauge how far down the tube you have gone. When you've pushed the wire far enough down the tube to have reached the EGR tube it intersects, you've probably removed all of the blockage(s)

Wait about 10 minutes for the chemicals to evaporate. Start the car and hold your finger in front of the metal tube. You should feel a steady stream of exhaust coming from it. If not, try cleaning it again.

While you're waiting for the chemicals to evaporate, now would be a good time to remove your EGR valve and clean the carbon deposits from the plunger and seat. I find that the carbon build up eventually gets bad enough to hold the EGR valve slightly open. This changes your base idle speed (TPS disconnected) and can also cause a rough and wandering idle as well as possibly causing your car to stall when you push in the clutch.

Reassemble the system, hook your EGR valve back up and take your car out for a ride. You should find that the problem is gone and your local smog police will give you an award for being a law-abiding smog free citizen once more.

I make checking the metal tube and cleaning the EGR valve a part of every tune-up and/or oil change.

Updated: 04/27/99