Located in South Africa, 2nd owner of a sluggish, silky smooth operation and idling, easy starting, night blue 1995 Maxima 300E (VG3.0 engine) RH drive with auto box and 235000km on the clock. Vehicle in pristine condition and it seems to require nothing more than simple lube/filter and a set of new NGKs every about 15000km ito maintenance. Oil consumption exactly "nil"

Had the car now for 4 years and simply love it - even given the inevitable (from posts here and elsewhere) auto tranny hassles still to be expected, and I see around 10.5k per litre on the open road - all very impressive in my books for such a "old" design...............

Spent the last 2 days reading this and other forums re the knock sensor causing sluggish performance because of my own situation. Been to the agents and :

1. They do not have such an animal for sale and have, in the last 10 years, not sold a single one according to their records.

2. I get conflicting opinions from so called "Nissan engine experts" at the dealerships - some say yes it may be the cause of the sluggishness, while others say they doubt it - yet cannot give me any other technically sound alternatives to try (normal other things to be expected all have been checked/replaced and rechecked and according to the dealership workshops they cannot fault the vehicle (the twits will not allow me in their workshops to witness how they go about determining that though!).

3. Given the high mileage of the vehicle and the much reported on auto box hassles, I don't want to stick it on a dyno with a twit operating the controls - I reckon I could still get quite a few miles out of the baby if I treat her kindly.

4. Nissan is willing to order and replace, from Japan a knock sensor (delivery 3 weeks!) - but at my expense with no guarantee and at a cost of $200 (R1400 local) for the sensor only ex labor (and they don't know exactly whats involved because they have never done one yet!)

5 Full service manual for this particular local model not to be found for any money by the looks of it

Now I have checked the connectors, and they seem to be ok - nice and clean with no rust/corrosion/white gunk - have cleaned and coated with Q20 before re-assembling them again - rubber boot on sensor pristine and the sensor itself underneath the boot a nice bright and shiny gold color - sensor reads around 530kOhm with a Fluke 27 multimeter measured at the connector right next to the rear rocker cover - electrically therefore in the ballpark of "ok" when compared to other posts seen on the subject.


Now what to do?

Do I import one of the sensors myself (much cheaper!) and take a chance?

Can one do any other tests (perhaps driving with the sensor disconnected?) and draw conclusion from that as to the state of health of the sensor?

Any insight much appreciated......................



PS : This knock sensor on my vehicle is located on the rear of the block (sitting in the car), under the exhaust manifold, just above the RH drive-shaft, to the right of the engine mounting - and its basically covered about halfway round by a recess in the engine mound bracket....................... I can see its going to be a ***** getting that thing out of there..................

 

wow, a 95 with a VG?
Do you have any pictures of your car and engine?
That would be most helpful, because here in the states, they stopped the VG30E engine in 94 (at least in the Maxima) and put the VQ30DE in the Maxima from 95-2002. It would be easier to give you help if we knew for certain what engine/car you have because you are the first person from South Africa I can recall.

I think most of the Knock Sensor problems relating to sluggishness are with the VE30DE engine, as well as the VQ. Also, the sluggishness is related to heat. On mine, I would have to drive the car for more than an hour at full operating temperature before any sluggishness was noticeable and it wasn't horrible, just noticeable.

There are other possibilities, but I wanted to see for certain which engine you have before throwing things out there.

 

Cheers for the interest, and believe me, this armpit of the Earth we call our backyard suffers for as long as I can remember from people dumping the last of anything on our markets - hence your surprise! (and mine when I nearly removed the intake to find no KS based on what other people said re different models!)

Want pics?...............

Here you go:

Front right
Enginebay front left
Enginebay front right
Enginebay front
Enginefront closeup
Driverside
Passenger+centre view
Rearview

 

Yep, I knew it. In the rest of the world they were selling the 3rd gen until 95. ame back home....anyways...

 

that is one beautiful max you have there! The corners seem to be the euro-style.

Ok some help finally.
Your car might be throwing some error codes at the computer that you can retrieve to diagnose. I'd suggest you do this yourself. I'll pm you some more info in a little bit.

 

Cheers - technically minded myself and no stranger to anything mechanical or electronic - so don't hold back on complex suggestions/ideas.

 

I like the grill you got there, it come with your car? I would like one for mine, Id paint it white to match...sry off topic

 

Grill is original for South Africa - Q Maximas has something similar here too.

 

yes, you definitely have a VG 3rd gen Maxima. Very cool, I might add.

Are these cars fairly common there?

Those corner lights and grill would be easy to sell if you could get them cheap enough. If you find some at a junkyard, shoot me a PM

Some VG guys will have to help you with your engine woes, however. Keep us updated.

 

I highly doubt the knock sensor, but the symptom is indicative of having the timing off by a bit.
Does the engine run better at high RPMs?

interesting how you have a 95 with the tailights from a USDM 89-91

 

No - unfortunately the average guy here seems to be looking for a "pocket-rocket" sort of vehicle and couldn't care less about value.

Quite a lot of these vehicles have been sold, but because their owners seem to really care for them 2nd hand spares are just about non-existent and breaker yards have very few of these to strip.

If I can find any loose spares in a decent condition you are going to have to stand 2nd in line I am afraid! I would have to say the car pulls "better" at higher rpms - but then don't all?

The 95 thing with older hw is nothing new here as I mentioned............

Currently working through all the ECM and error codes, and if nothing shows up I will persue the timing off thing a bit further - though not impossible jujdging by the broken bits off the edge of the crank pully after a cambelt job by the agents

 

a 300e 3rd gen ? AWESOME ! i love learning new stuff about this car !!!

 

All responses much appreciated guys.

Thanks especially to lophix for organizing a seriously impressive FSM.

So I have read through the technical stuff, and worked through all of the error reporting mechanisms of both the engine ECU and the gearbox ECU and have come to the conclusion I must be mad. The engine ECU reports error code 55 which means it hasn't seen anything wrong on the vehicle since the last battery change about 5 years ago while the gearbox has 10 flashes of equal duration also effectively saying its perfect - It must therefore be me thats defective no?

I have also checked the timing - sitting rock steady at 15 degrees as per spec.

So now to trace the cause of sluggishness I am stuck having to check the fuel pressure and cam-belt timing - I am busy getting the plumbing organized to have a gauge tell me all about fuel pressure after the filter before the injection rails, but am not too sure how to go about checking the cam timing without effectively going through the motions of replacing the cambelt.............. (I did discover the so called "agents" managed to damage my crank pulley when they obviously tried to pry the pulley of by forcing screwdrivers etc behind the pulley ISO using a proper puller designed for the job - may the fleas of a thousand camels infest all of their armpits!)

Anybody with a clever "trick" to confirm the twits didn't screw up when they replaced the belt?

 

Check out this site for trouble shooting.http://www.zhome.com/ZCMnL/PICS/hesi...sittation.html
I have had alot of problems with mine it was a combination of adjusting TPS and intermitten failure of MAF. IT SCREAMS and IDLES perfect. It only took me 3 weeks to get to the problem. My code was 12 and I wish I would have believed it but a Master nissan mech told me they fail permantly Not intermittenly. GOODLUCK

 

So I have spent the last week checking and rechecking everything that I could think of that may be causing the sluggishness...................

ECU codes all pan out as normal, and every relevant troubleshooting guide I could find in the FSM was followed with no solution.

Got to thinking here:

I stay up at 1730m above sea-level and can only get 93 Octane fuel around here at the pumps, and on all my other vehicles I own I have to advance the timing by about 2 or 3 degrees in order to compensate for the thinner air causing slower burn rates at combustion. So eventually decided to give that idea a spin, and set the timing at 17 degrees - WOW is all I can say! - its like a new car! - much, much better pulling now.

So I have been reading here that some guys say they are running at 20 degrees, and thats puzzling. I have tried advancing my timing some more in one degree steps accompanied by a testdrive, and find I can hear the motor starting to ping at around 18 degrees when taking off a little briskly.

How to reach 20 degrees then if thats optimum? (is it in fact - why does the factory recommend 15 degrees?)

As I said - Dyno is out because of the high mileage on my auto box.

 

Umm, you have to ask why lead is added to gasoline - in simple terms, to prevent engine knock (pre-detonation). Leaded gas & unleaded gas have different burn characteristics.
It's possible the "mod" they're talking about is a chip upgrade to the ecu - unless the heads are specifically manufactured for SA and the valve seats need to be replaced (def doubt that!!!).
Okay, so if Nissan SA remapped the ECU to take into account leaded gasoline, then your car shouldn't be sluggish as a result. It is entirely possible that the ecu in your car is not SA origin - i.e. from a country where Maxima's run on unleaded gas (nearly all Maxima markets!!!), so that may account for sluggish response at low speed.
It's obvious from your inspection of the combustion chamber that the car is not running rich, so fuel pressure is probably not a problem. And because you're getting no error codes from the ecu, it's probably not a bad sensor. I would suggest heat soak restricting breathing, except it runs fine at higher rpm (and I'm guessing it's been sluggish all thru winter as well - when it's not that warm!).

So, maybe the problem is not engine related - it's possibly be the torque converter not working so well, or the tranny oil pump is a little worn, thereby not supplying the torque converter with enough fluid at lower revs. As the engine has 235000 kms on the clock, if the tranny hasn't been replaced or rebuilt yet, then it's def past it's use-by date & you've had value for money from it (normally start failing around the 180 - 200k mark). If you haven't changed the tranny oil in a long while, this could be your problem (needs to be changed every 2 years or 30,000 kms at least - I do mine annually). Also, check the cooler lines while you're at it for any restrictions.

 

Once again thanks for the interest and comments.

Hmmmm

1. Fuel pressure - no - been driving around with a fuel pressure guage hooked up since I started my investigations, and can find no correlation to the possible sluggishness. What I have decided though is that the pump is no longer 100% - I find fuel pressure drop off to 0 from its avg 38 psi within about 3 seconds of shutting down the ignition - to me it indicates I may sometime in future start experiencing difficult starts. (or is it normal? - FSM doesn't seem to address the particular point)

2. Heat - also no - winter time I saw the same performance

3. Gearbox oilpump - had to think about that one for a minute. Lets say its wonky, then the converter would possibly not be able to lock up in both 3rd and overdrive - since thats not happening happening and I can really not find any other slippage etc in the box its unlikely. 3rd gear with overdrive off I did still experience the sluggishness.

4. Gearbox oil quality - also no - the only previous owner of the vehicle was a maintenance nut and stuck to his maintenance schedules (have all the records to show for it). Currently the oil is nice and red in color with no burn smell and I have changed it at 220K anyway.

Perhaps you missed it, but I have discovered and reported a marked improvement by advancing the initial timing to 17 degrees, but due to pinging starting to be detected at around 18degrees I do not want to go further toward the 20 degrees some guys here are reportedly using.

Maybe I should just say enough is enough and accept the fact that the vehicle has done a lot and is still a pleasure to drive and accept it as it is currently.

 

We probably can use 20 degrees because most of us are a lot closer to sea level than you are.

 

Dunno about that........................

Denser air implies better and earlier combustion - advancing the ignition timing closer to sea-level will surely only bring on pinging a lot earlier therefore than in my case, so it would surely prevent you guys from running at 20 degrees - no? (unless you ignore/cannot hear the pinging?)

If my reasoning suck, then please set me straight.