This is for the Tech Heads

El Fuego · Jul 12th, 2004, 10:25 PM

THIS ONE IS FOR A TECH HEAD!!!

I am so glad to have found this site. I thought I was all alone in loving my Altima but
experiencing problems from time to time. Most mechanics are intimidated by the foreign components and just act as if they know what they are doing. I'll be a supporter of this site during the life of my Nissan. I will be as specific as possible. Hopefully the more information, the more accurate some of the diagnosis will be.

About 4 months ago I started to experience problems starting my vehicle. It would take
2-3 attempts for the engine to turn over. Once the engine did turn over the
car would idle very low. The car would shake/hesitate (as if gasping for air). If I left
the car idling in park for 30-60 seconds, the car would cut out and I would have to start it again. I took it to Auto Zone and had them run the vehicle in order to check out the codes (the check engine light had come on). I don't remember the exact code numbers, but
I know that the two codes that come up were for the EGR VALVE and the KNOCK SENSOR.

At this point the vehicle runs rough, but gets me to point A and B while
I'm investigating solutions. A couple of weeks passed and I notice that it became more
difficult to start the vehicle. After it turns over it seemed to die more quickly. I noticed that when I would give it some gas while in park the idle would pick up for 10-15 seconds and smooth out, only to drop back low and run rough once again. This problem was compounded by a problem with acceleration.

When stopped (say infront of a light or stop sign), the car continued to =
run rough (low idle) but I then began having trouble taking off. When I would accelerate
the car in order to move forward, the engine would hesitate and often choke off and die.
I would have to start it again and be careful in how I would accelerate. The most successful technique I found was to gentle press the gas pedal and accelerate very slowly in order to get the rpms up. Once I was going 30-40 mph, the problem seemed to go away. My next step was to follow the code. I realized that the KNOCK SENSOR CODE probably came on due to the rough idling, etc., so I started with the EGR VALVE in hopes that this would solve the problem and I'd have my Baby back working smoothly. I replaced the EGR VALVE and scraped out the proper areas (removing excess debris) before attaching. This did not help. I return the EGR Valve for a new one hoping that it was defective. To know avail, the car had not improved it's performance. I thought my next step would be the spark plugs. Though they were changed some what recently, I took the chance and replaced them again. This was not successful. By this point the performance of the car had depleted to the point where I was having to put the car in 1st gear (its an automatic) to accelerate up to about 15mph, the up to 2nd gear and accelerate up to around 30mph, then slip into drive. This was the most successful way for me to take off with out the car sputtering and cutting out. (Not a very
safe way to drive, let me tell you). As a student, with tuition and so on, I was doing my best to try and avoid having to pay high diagnostic charges, plus, I have been burned so many times by unskilled mechanics who own chop shops that I was concerned and reluctant to take my car to anyone. I knew good mechanics were out there, I just didn't know where to go. Eventually a local man had been recommended to me and I eventually saved up the money to have it diagnosed. The guy called me in the next day said that I had a intake gasket leak. He
showed me the leak by taking some "gumout spray" and sprayed over the two fuel injectors
located closest to the drivers side. When he sprayed the "gumout" the car idle immediately
picked up. After he stopped spraying, a 1-2 seconds would pass and the car idle dropped
down dramatically. He was a helpful and said that the it would cost me close to $400 to fix
the problem through him, but that since I was somewhat experienced and mechanically
inclined, I could do it myself. He showed me what to do and printed out a computer print out
with a diagram and instructions. I took that and my Haynes manual and got to work.

My first step, before getting all into the intake manifold gasket replacement, was to check
the O-RINGS for the fuel injectors (the ones that secure the seal of the injectors into the
intake). Replacing them was a much easier task and would hopefully solve the problem.
I removed them, they were damaged, but the new ones did not solve the problem. So now
I'm down to facing Goliath.

I purchased the new intake gasket for $12.00 or so and started to work on the car at around
2:00pm. With in an hour or so, I removed most of the necessary parts (fuel rail, bolt
underneath the car that secures intake, and the outer bolts intake bolts, top intake bolts).
At this point I feeling great. Only two bolts left. My knuckles were a bit scratched from
having to remove the initial intake bolts, but nothing prepared them for the next 3 hours
as I tried to remove the last two intake bolts. The are located at the bottom row, in the center.
I CAN'T GET THEM OUT...HELP ME!!!!

Here are my questions:

-First and foremost...am I on the right track to solving my problem by replacing the intake
gasket?

-How do I remove the two center, bottom row bolts? Do I need a special tool to get the right angle? The seems to be a thin bar which lays behind the bottom row of the intake. It seems more impossible to remove the anything else. I've worked around it to remove the other bottom row bolts, but can't get to the center ones. Not enough hand space to work a wrench, no way to
angle my ratchet/extension. I need so wisdom!!

-My Haynes manual hasn't been as much help as I hoped. Is Chilton's better?

Thanks for the patience to read about my situation. Any expertise would be greatly appreciated. My car has been laid up for almost a week now with 2 bolts holding me back. I want my Baby back.

Signed,
A student determined to fix his Altima! (Antonio)

KA24Tech · Jul 15th, 2004, 03:45 PM

I answered your PM and I hope it helps.

Troy

**Asleep** · Jul 15th, 2004, 09:25 PM

my computer is in pieces at my new roommates house so i havent had a chance to answer the pm i got from you... ka24tech knows what hes talking about though, so any answer you got from him, you can be assured will be as good as it gets.

Boughtabadone · Jan 27th, 2007, 06:00 AM

Quote:

Originally Posted by KA24Tech

I answered your PM and I hope it helps.

Troy

I am in the same boat as El Fuego. I have left my 93 Altima in parts waiting in my garage until I have the courage to tackle re-assembly. I was able to loosen the 2 bolts with a wrench but one of them (the one closest to the distributor) I actually had to use 2 screwdrivers to back it out 1/6th of a turn at a time. It would only fall back into the previous position when I tried to use the wrench, as it was too loose to get the wrench to take a second bite for another 1/12th turn. This one bolt alone took an hour to remove, almost as long as the rest of the dis-assembly altogether. Soooo... here is my question. I see that you sent advice on this chore to El Fuego through his PM. Would it be possible to send me the same advice? I do not look forward to attempting this again until I actually talk with someone that has already successfully performed it.

Thanks for you time. I have gained lots of insight by reading your posts. AsleepAltima gives you the thumbs up as well so you must really know your stuff.

Thanks - Tim

KA24Tech · Jan 30th, 2007, 12:17 AM

I don't exactly remember what I wrote in that PM since it was in 2004, but It helps to have the car up on stands. You need to remove or just loosen the intake support braces on the bottom. Also there are several hoses that need to be removed in order to get the space you need to clean the old gasket off and clean the surfaces. It is difficult to get the fasteners off the upper manifold plenum and usually I will remove the lower manifold to get to the top from underneath. You will need to get a new gasket for that as well and you really need a good torque wrench to tighten everything properly. The other alternative is to remove the head with the intake manifold attached as this makes the job easier. The downside to that method is it takes more specialized tools and definitely a factory service manual in my opinion however, it is possible with a Haynes manual.

Troy

Boughtabadone · Jan 31st, 2007, 10:37 PM

Thanks Troy... finished the project. Replaced the gaskets for the plenum and the manifold. Ended up using the technique from the bottom for the driver's side bottom bolt but couldn't get to the passenger's side from underneath. Found out that if I used a 12 mm 1/4" drive socket with a 2" extension and my 1/4" drive ratchet that I was able to come in from the side of the manifold rather than from the top. This process would have saved me about an hour if I had used it when taking the bolt out. The extension gave me the clearance that I needed to get by the tube that runs the length of the manifold between the plenum and the upper manifold runners. I should post some pictures in case others need the information.

Thanks Again.

Tim

rod_88 · Jan 31st, 2007, 11:35 PM

All I know is that you need some mechanics gloves, I know itsw not much hewlp but they will keep your hand ok. (saves stress)

getnbizzy · Oct 30th, 2007, 09:52 AM

Sure wish you would've posted the results. Did the intake gasket cure the rough running condition?

jserrano · Oct 31st, 2007, 03:54 PM

I don't know if it is Ok to put up a link to an external site for anyone interested in how I did my intake gasket replacement. Anyway, here is the link

Nissan Enthusiast Forums - My Intake Gasket Replacement

Mods: Feel free to delete this post if it goes against forums rules. Thanks. -jserrano

Altima SSS · Nov 1st, 2007, 06:24 PM

That's an insane job to replace the intake manifold gasket. I think if I needed to do that on my 94 I'd just part it out.

Some of the manuals I've seen say it's easier to remove the head & complete intake manifold as a unit ... might be the way to go.