I’ve read the threads but found none that may apply.
My car is diseased; being a scientist, I want to do more than just say a prayer and a Hail Mary in the hopes that it gets to the top of the hill!
Runs fine on flats and downhills.
In February 2015, an “engine light” indicated that my catalytic converter was malignant. Had it changed.
THe mechanic noticed that the car had little activation energy (i.e. acceleration and delivery of power was not directly proportional). I had it too, but, thought nothing of it. He suggested changing all 4 spark plugs. I agreed. For the first three months, the car exploded going on uphills.
It’s now May 2015, and the car feels impotent - has an engine, but doesn’t deliver on power. I accelerate, the motor’s RPM goes higher, but the output is slow. What is slow? In uphills, slow aking to having to be with the big rigs and trucks.
Would anyone be so intrigued as to provide a course of treatment?
Manual transmission? get on a hill, go 15mph, put it in the top gear, and floor it. If the RPM rises rapidly but the car doesn’t accelerate, you have a worn clutch and need a new one.
A slipping automatic and a thoroughly incompetent mechanic could be your problem. In medical terms, your mechanic is a quack!
A proper engine evaluation will determine whether your compression, fuel system air intake, etc. are up to snuff. “Exploding” applied to an engine is not a very scientific term. What actually happened?
“I accelerate, the motor’s RPM goes higher, but the output is slow.”
This is a classic symptom of either a slipping clutch or an automatic transmission that is…unwell.
Since the OP has already told us that the car has an automatic transmission, then the clutch issue can be ignored.
The OP should do the following:
Immediately check the level, color, and odor of the transmission fluid, and then report back to us on his findings.
Start asking friends, neighbors, relatives, and co-workers for the names of recommended independent transmission shops. (Do NOT go to Lee Myles, Cottman, Mr. Transmission, or <> AAMCO.)
Start looking for a new mechanic for non-transmission-related issues.
For future reference, the OP should try to remember that automatic transmissions need to have their fluid and filter changed every 3 years or 30k miles–whichever comes first. On the basis of elapsed time, this vehicle should have had that service done at least 4 times so far. If that hasn’t been done, then the OP should consider that the major factor in why his transmission is now failing.
I am going uphill, am accelerating, and the car is moving slowly.
I’m at about 65mph, RPM’s is abouy 4-5, and the car is moving upwards at a speed of that of a gas tanker.
In response to VDC Driver, I will check the color, odor, and level of my transmission fluid - and report back tonight.
“I’m at about 65mph, RPM’s is abouy 4-5, and the car is moving upwards at a speed of that of a gas tanker.”
This is just more evidence of a badly-slipping transmission.
If the OP is VERY lucky, it will turn out to be merely a case of a low level of fluid in the trans, but–of course–that also indicates the probability of a transmission leak, so even in this best-case scenario, the services of a good independent transmission shop will be necessary.
Can the OP please tell us about the service history of his problematic transmission?
OP is internet talk for Original Poster, namely…you.
“I have no prior history of a problematic transmission.”
Okay…fair enough…perhaps this was a poorly expressed thought on my part.
I will rephrase is as…Can you give us the service history of this transmission that now appears to be problematic?
(Translation=How many times was the trans fluid changed over the past 14 years?)
OP = Original Poster. That’s you Nissan blues
It sounds like a slipping transmission to me. By slipping I mean that the RPM goes up, but the car maintains the same speed.
Don’t shoot this OP, but, in the time that I’ve owned it (2003-onwards) and keeping a comprehensive maintenance records (just a quick aside: after 100K, I contacted the Nissan headquarters and asked them what do I do now since your car maintenance log only goes up to 100K), I am unaware of any one moment in time when my transmission fluid was drained and added a clean batch.
I can go a few step forwards: When I’ve taken it to a Nissan dealer and other independent mechanics for engine oil changes, their responses (because I asked) was: “all other fluids are fine; no need to change or add more.”
I told my Parents that I wanted to take a mechanic class in high school instead of photography. Now I would at least know about changing spark plugs around or being cognizant of all fluids need to be changed - no matter what.
It sounds like an engine performance problem, I doubt you will be able to find the problem on your own. You will need to have a mechanic inspect and drive it.
If the engine has a failing spark plug or ignition coil the check engine light should be flashing and it would be difficult to reach 65 MPH on flat ground. A transmission won’t slip for long at that speed without burning up, perhaps 60 seconds. You are going to have to have someone diagnose the problem.
My first suggestion would have been to run a compression test while the spark plugs were out. Granted, you state that the engine had power after a plug change but some of that could possibly be due to the placebo effect.
If the engine is getting a little tired spark plugs will start downhill. With new plugs a slight improvement may be noted but will be short-lived.
I’m a firm believer in making sure the engine has the gumption to do the job; ergo, the compression test.
If compression is good then transmission slippage comes to mind. A converter stall test could be easily performed but I don’t know whether to recommend that or not as it would be easy for someone to finish an iffy transmission off while doing the test. Done right it shouldn’t be a problem.
"He suggested changing all 4 spark plugs. I agreed. For the first three months, the car exploded going on uphills. "
Did the mechanic use OEM plugs?
For a Japanese car that would be NGK or Denso brand of the same part number in the Owner’s Manual and usually on a label on the underside of the hood.
Here’s a little science for you:
The manufacturer designed and tested the engine with a spark gap of a certain size and position within the combustion chamber.
Number and shape of ground electrodes affects shrouding of the flame front.
These are important to performance and critical in some (often with Japanese) designs.
Can you count on another brand meeting those specs? Not always.
For driveability problems I always recommend getting the valve lash checked/adjusted and a compression test.