Low Rev Problem

When I first drive my car from cold I have a problem with the revs dropping below about 800rpm.Its almost like the engine is about to stall.Sometimes it will eventually come right, but usually I have to use a bit of accelerator to increase the revs. I also notice this when Im slowing down approaching traffic lights and I put the car in neutral, the revs drop really low and the car takes a while to adjust. I have put a Cone Style AirFilter on, no other mods. Any ideas what the problem could be, maybe a good tune or something. Is it normal?

Another problem that has occured after putting on 17 inch wheels is that there is a funny rattling coming from the engine bay when the engine is at those low (pre 800) revs. It also occurs when the road is really bumpy. I think something has loosened up a bit much from the rougher ride that the low profile tyres have. It is almost like an engine mount is loose, but ive had them checked and they are apparently all fine. Any ideas or common problems with attachments coming loose around the fire wall or back of the engine?

Originally posted by AWD Primera
When I first drive my car from cold I have a problem with the revs dropping below about 800rpm.Its almost like the engine is about to stall.Sometimes it will eventually come right, but usually I have to use a bit of accelerator to increase the revs. I also notice this when Im slowing down approaching traffic lights and I put the car in neutral, the revs drop really low and the car takes a while to adjust. I have put a Cone Style AirFilter on, no other mods. Any ideas what the problem could be, maybe a good tune or something. Is it normal?

The first thing that comes to mind is that your base idle may need to be reset. This is a common symptom of the base idle being too low (revs drop and come back up). It could also be an issue with your AAC valve. Of course it could be other things.

Here is the best tune-up guide for the SR20DE:

http://www.se-r.net/engine/troubleshooting_guide/index.html

Originally posted by AWD Primera
Another problem that has occured after putting on 17 inch wheels is that there is a funny rattling coming from the engine bay when the engine is at those low (pre 800) revs. It also occurs when the road is really bumpy. I think something has loosened up a bit much from the rougher ride that the low profile tyres have. It is almost like an engine mount is loose, but ive had them checked and they are apparently all fine. Any ideas or common problems with attachments coming loose around the fire wall or back of the engine?

Do you get a buzzing noise when you get off the throttle? The front engine mount (driver side for you) is a common problem on the Sentra SE-R (B13 with the SR20DE). I've heard little problems with the P10, but it's possible. What happens is when the engine is decelerating, it rocks, and if the front engine mount is bad, it can contact the coachwork and make a terrible buzzing racket.

I don't know if this is the problem you are having, but it's a possibility.

I've found 2 things that buzz on my T4 - the washer bottle lid against the fender - around 1200rpm, and the front inner guard on the flat flange bit that rests against the wheel arch - at various rpm. Other things that may have loosened up are the grille and front bumper cover. Please let us know what you find:)

Thanks for the help guys. Ive already fixed the washer bottle and front guard rattles- I had the same problems. The rattling noise is not all that loud. You can drown it out with the stereo. Sounds like it is at the back of the engine rather than the front. Thanks for the advice, any further help would be much appreciated.

I had this EXACT same problem, ,but instead of my engine correcting itself and bringing rev's back up, it would totally stall... i would usually have to "catch" the needle from falling by tapping on the gas. It got to be a pain in the ass after a while.

Eventually, i took it to my Infiniti Dealer.. (OH CHIT! There goes my arm and leg........ dealers bleh..). It ended up to be a fused AAC valve. it fused frorm the extreme heat of Houston, since i leave my car outside usually (no garage room.. we have a pair of maximas in there...as#@#$#@#$f!). Ended up costing quite a bit......

IMO, have somenoe checck it out for 80 or so bucks, buy the replacement part and stick it in yourself. Saves a couple hundred bucks.

Originally posted by ricecube77
Eventually, i took it to my Infiniti Dealer.. (OH CHIT! There goes my arm and leg........ dealers bleh..). It ended up to be a fused AAC valve. it fused frorm the extreme heat of Houston

Usually an AAC valve can be cleaned as well, although I've never personally done it.

For those who are wondering, the AAC valve is the one that controls the idle.

I finally got around to finding the problem that was causing the squeaking in the engine bay. The only problem now is how to fix it. So here goes:
The squeak is coming from an engine mount that is at the back of the engine, between the firewall and the engine. It is the one in the middle, up quite high, in about the same position as the throttle intake. There appears to be a sort of rubber thing that is between the centre and outside casing of the engine (its hard to get in there and see). I can wiggle this and its casing from side to side, its quite loose. When I do this I makes a squeeking noise as a result of the rubber rubbing on the casing or the middle of the engine mount. What I need to know is- do I just lubricate this to stop it squeaking, or do I have to tighten something up so that it doesnt move as easily. Any Help from engine experts much appreciated! - Im a novice!:(

I'll have a look at mine and see what it's all about. I think our engines are mounted a little differently than the FWD models.

Does anyone else know if the 2wd Primeras have an engine mount in the same position?

I've had a look at that mount on my car and found the same sort of thing. There doesn't appear to be any weight on it so I guess it only counteracts torque when driving.

I can also grab hold of the plasticky sort of link (running from the firewall bracket to the rubber bit mounted on the engine bracket) that surrounds the mount and wiggle it side to side quite a lot and back a forth a bit too. It also makes the creaking/squeaking sound when I jiggle it but nothing appears to be loose. I haven't noticed any noise while driving though.

The noise just appears to be the outer link thingy rubbing against the rubber bit. If it annoys you enough I can't see any harm in taking it apart and putting some rubber grease between the parts. Make sure you don't use a grease thats gonna damage the rubber though.

I also noticed that the transmission has 2 mounts, front and back, on it. Can anyone confirm if it is like this on FWD models?

Hey, thanks man. Most appreciated. I guess the noise is due to the fact that it is not lubricated enough. I might try pulling it apart and putting some grease in there. Teflon based grease shouldnt effect the rubber at all, should it?:confused:

Originally posted by AWD Primera
Teflon based grease shouldnt effect the rubber at all, should it?:confused: Dunno ... I'd use a silicon lubricant or O-ring grease but only coz I've got some lying around in the shed.

where can i get the AAC valve from
discount or dealer?
and about how much will it cost?

GT Call these Hank at Automotive Super Service in Lauderhill, FL

954 746 2846 , they got me straight with mine for a little $

so about how much $ ?????

I'm new- I've got some screw drivers and some WD-40 and I'm not afraid to use them!!

Ok- really. I have a 93 and the idle was really inconsistent- sooooo...

i checked the sparkplugs- (had some water in the wells before) blew out the water with air... pulled the spar from the plugs one at a time and noticed that when i pulled the second from left (when facing the car) there was no difference in idle... - so- that one was bad.

but to be sure- i swapped the sparkplugs with another cylinder and tested again to make sure it was the plug-

nope

it was something to do with the cylinder. i pulled the injector- saw some crap around the filter for the fuel and then put it back in...

started it up- and then-

SMOKE ALL OVER- PLUMING OUT FROM THE BACK OF THE CAR.

purchased new injector (90 bucks) and then- no smoke...

but- still some problems with idle...

so- removed BPT valve like what it said on the SER.net site...

started car- and car runs REALLY FINE..

nice idle.

but - i can't drive the car around without a BPT valve-

OR- CAN I?????

ANY ADVICE- GREATLY WELCOME!!!!!!!