RandyMax

My car (96 SE 5sp, 133k miles) feels very sluggish in low gears (1st and 2nd) in low rpms (below 1500). The engine bogs down big time when I try to accelerate. On a bad day, the car barely accelerates from below 1500 rpm even if I floor it in 2nd gear. Once it gets up to around 2000 rpm it comes alive. It feels kind of like having turbo lag WITHOUT the turbo!!

The situation gets worse if the car's been sitting under the hot sun for a while, and the AC is on.

The check engine light is not on. However, it was on for a while 2 months ago, but the stupid mechanic accidentally reset it. It hasn't been on since.

What is going on? Any suggestions anyone? Mr. Martin?

matty

iTrader: (54)

A previous post a while ago about low RPM's daniel B said to always keep your rpm's above 1500 cause this will prevent any engine wear and transmision wear...this happens with my 96 with 90K as well all i do it shift to either third or 2nd (however fast i am goin) and let the VQ breathe...i like keeping it right at 2K

Daniel B. Martin

Matty didn't quote me exactly right. Low engine speed won't hurt the transmission at all. Low engine speed is unkind to the engine because oil pump output (volume and pressure) is proportional to engine speed. If you floor it below 1500 rpm you are asking the engine to do some hard work with minimum lubrication. Think of 1500 rpm as a low-end red line.

The air conditioner is the biggest of all accessory loads. You should expect to notice the effect of having a/c on versus off. However, flooring the gas pedal should result in the a/c compressor clutch being momentarily disengaged.

RandyMax

Thanks for the input.

However, what can I do about the "sluggish-ness"? Keep the RPM up at 2k and let the clutch slip till the car gets going? I'd rather not. I don't want to wear out the clutch again. In 133k miles, I've already gone through 3 clutch assemblies...

matty

iTrader: (54)

go to a lower gear if it starts to slip...you need direction if you went through 3 already at 133K ...not a flame but im tryin to give you imput

Daniel B. Martin

Your Maxima was due for a scheduled maintenance at 120K miles. Was that service performed? It would have included new spark plugs and a new air cleaner filter.

Here are some other ideas for your consideration.

1) Clean the inside of the throttle body.

2) Replace the fuel filter.

3) Check the Throttle Position Sensor. For further information see the Chilton repair manual (page 4-18) or the Haynes repair manual (page 6-8).

4) Are your Oxygen Sensors the original equipment? After 133K miles they are "tired". Have them tested or just go ahead and replace the two front Oxygen Sensors.

Dave B

You really can't expect the Max is be fast at 1500rpms. At best, you're only making about 40hp. When you "whack" the throttle at 1500rpms, the car is FAR from it's useable torque and hp. You're also dumping quite a bit of fuel in the cylinders when you go WOT at 1500rpms. You need to ease into the throttle if you're at that low of an rpm. Overall, I would recommend not doing this often. Even my car would feel "boggy" if I tried to go WOT at 1500 in 2nd. WHen I take off from a light and I want to go WOT, I slip the clutch till about 2500rpms to get a strong launch with no wheelspin.

If you are trying to race at 1500rpms, you're gonna be very slow. From a stop, you should be coming off the line near 3500rpms within the first few feet. From a roll on race, you'd better be at 3000 or you'll get caught with your pants down.


Dave

_DRU_

so the AC on really doesnt affect the 1/4 mile or 0-60 times of our cars does it?

matty

iTrader: (54)

I swear I feel and here a difference in the engine May be my imagination

JdawgX

The key to Daniel's quote was "momentary" It doesn't just turn off the A/C So yes 0-60 and 1/4 mi. times are still greatly affected.

Daniel B. Martin

The factory service manual doesn't provide specific information on this point. It gives the impression that the a/c compressor clutch is disengaged whenever the throttle is wide open. For an automatic transmission that would be for the entire 0-60 mph acceleration time. For a 5-speed it might mean the clutch engages every time you "lift" to make a shift, and then immediately disengages.

RandyMax

When you are rowling in second you don't down shift to first, do you?

I am still wondering why I have gone through 3 clutches in 133k miles btw. My previous car, well, a small pickup truck to be exact, lasted 90k without any clutch replacements. And I don't race so I never launch the car hard.

The first 2 clutches (37K, 72k) was replace when I brought the car in due to a groaning noise from the clutch. First was free though. (warrantee) I always wonder if I got gipped in the second one, because I have to replace the clutch again around 110k due to excessive slippage. Oh well...

But anyway, thanks Daniel for the input. I've replaced all spark plugs and air filters at 120k service. So, I think the O2 sensors might have been the cause of the sluggishness, since they are all original equipments. I'll have them checked out.

Thanks.

matty

iTrader: (54)

When I'm rolling I abolutely never put the car into 1st... you get this major jerking back and forth that the car makes and its bad for the sinkrows in the tranny...


peace

_DRU_

shoot... now you tell me...

RandyMax

uh huh. that's why I am complaining about the sluggishness. stupid car won't accelerate from low rpm in 2nd...

I am gonna take Mr. Martin's advice and have the O2 sensors replaced and see what happens...

JdawgX

The only time that you would get a "jerking" is when you let the clutch out very fast. You can in fact put the car into first while rolling smoothly. Though you shouldn't be rolling very fast or it is bad for the synchros. However, you can put the car into first safely while rolling. And by the way, you may want to have your O2 sensors checked before you replace them. You may save yourself a lot of money Just something to think about.

Daniel B. Martin

You are hurting the syncros if the shifter "fights you" or the transmission makes those ugly grinding sounds. If the tranny goes into gear smoothly you are not hurting the synchros. My Maxima will shift from 2nd to 1st smoothly at 20 mph if I "speed match" by goosing the gas while making the shift.