Engine Noise

[James]

Hey,
This may be a stupid quesiton, but I will ask anyway. Are carbed engines generally louder than efi? Oviously I am comparing comperable sized engines. A 4cl efi with a 4cl carb, etc. The reason I ask is becasue I notice that my car's engine is generally louder than any of my friends. I am the only one I know who has a carbed engine, everyone has 90 cars and above with efi and my car is almsot the loudest. The only car that is louder is my cousins V6 from a 4Runner.

Also, I have noticed that when I idle and turn the a/c on. The rpms drop from about 700 to like 650 and the stirring wheel starts vibrating a lot. Also, the engine sort of rattles whenever I am idled, not matter if the a/c is on or not. Is there a common cause for rattling. Obviously it could be anything, but is there a more common reason this occurs.

Well if you could help I would greatly appreciate it. BTW, on the older boards I was Accord86Dude.

Later,
James

[ACCORD EX]

check out this FAQ about tuning the whole carb http://members.fortunecity.com/accordex87/carb.htm

be sure to have a a spray of carb cleaner with you !



MIKE

[Don87LX]

Sounds like your idle needs to be raised a tad. Also your engine mounts are probably worn out and that would translate morevibration from the motor to the frame.

[shepherd79]

When you turn your AC your RPM should get higher around 1200.
I don't have AC in my car but i bet that your problem is vacuum leek.
I have 4/75 (4 windows down and 75 mph) AC.

[volvohonda83]

Nah, the idle speed always drops when you have the AC on becuase it's using more engine power, and so your RPM's drop. I don't know if it's on EVERY car, but it does it for my 89 LX and my dad's 92 Civic LX. It does it some on my mom's 2001 Chevy Impala also. Sooo... I don't know of any other car who's RPM's go UP with A/C.

[hondaisthebest]

On my carb car my idle is around 1250 when i put the ac.
On the carburator you suppose to have a valve that pull the throlle cable when you put a/c.
Dont know the principe for efi but maybe the same.

[Don87LX]

The carb as the AC idle booster. It is another idle screw on the carb. When you activate the AC the idle booster takes over and up the idle to keep the car running smooth. I dont know but I imagine the FI has a similar system.

[James]

Ok, thanks for all the replys. I will probably mess with the carb screws. Also, is there anyway to tell if your motor mounts are bad, by looking at them? I wouldn't think so, but I wouldn't know. Thanks for all the help. Later.

[ACCORD EX]

i think motor mounts are worn when the rubber is cracked ! you can check the rubber by hand !

MIKE

[James]

Well, they arn't cracked. I checked. I jurst recently replace the front and rear ones. The car almost never vibrates. Sometimes when it is cold out, it will a little, until I put it into drive. Other than that, the only thing taht vibrates is the steering wheel.. Yet, that only vibrates when the AC is on. Also, just yesterday, I was at a drive through and I opened my window. I heard this whining sound comming from my engine. It would whine for a second, then stop, then a few seconds later it would whine again. I hope nothing to bad is messed up. I have not money as of right now. Could it have anything to do with my timing belt? I am overdue on that, about 5,000 miles. I am getting it replaced sometime this week. Well thanks for the replies so far.

[Don87LX]

Sounds like it could be the water pump shaft bearings could be shot. Also you PS system can whine if it is low on fluid. check that.

[shepherd79]

Originally posted by James
Also, just yesterday, I was at a drive through and I opened my window. I heard this whining sound comming from my engine. It would whine for a second, then stop, then a few seconds later it would whine again. I hope nothing to bad is messed up. I have not money as of right now. Could it have anything to do with my timing belt? I am overdue on that, about 5,000 miles. I am getting it replaced sometime this week. Well thanks for the replies so far.

did you had your AC on at that time?
i think it is normal for AC to do that.
correct me if i am wrong guys.

[SephirXV]

Did you get anywhere with your problem?
I'm having one that based on engine RPM, and having no luck finding the source of the sound.
https://www.3geez.com/showthread.php?t=45213

[Blkblurr]

Your idle is too low when your ac is on. Get that taken care of and you should be good on the vibration. The whine may be your compressor, belts or your fan that comes on when your ac is on. The cycling of your compressor may cause it to come and go. You may also have low freon if your compressor is cycling frequently.

[biloyp]

I have the same problem, when my A/C is on in gear, my dash and steering wheel vibrates. I adjusted the A/C idle screw to raise the rpm's so the vibration would stop and it did indeed cause the vibrations to lessen to almost nothing. Only problem is, when the fan comes on, the idle raises and my rpm's go up to 2000. f I try and shift into gear like this, my car jerks when it goes into gear. I realize this is due to the high rpm's and shifitng at this point so I guess it is a good idea not to shift into gear when my fan is running and the rpm's are up around 2000.
Just thought I would add my 2 cents, I plan on driving my car a bit and check if indeed the vibration is gone when A/C is on and car is in gear but stopped at a stop sign or light.

[Rendon LX-i]

I have to hold the gas down a bit to keep it from shuting off. Im trying to figure why it does that. Ummmmmm Vacum leak i dont have one ive check plenty of times. I dont see why its doing it. is there a AC idle booster on FI accords? If so thats probly my problem if ther is one?

[FyreDaug]

Holy 3 year thread revival batman!!

[Rendon LX-i]

HAHAHAh i didnt even look at the DATE. lol my bad.