Can rough idle be caused by too thin of a motor oil?

Messages
85
Location
Grand Forks, ND
1994 Honda Accord EX (Aprox. 94K) I've used Mobil 1 for the life of the car and one thing I've noticed is rough idle with Mobil 1 5W30 and 0W30. The engine runs outstanding when driven; however, rough idle is sometimes present when stopped at a stoplight, for instance. The car has no oil consumption issues. I use Mobil 1 0W30 during the brutal winter months. The rough idle is the worst during winter with the 0W30. I use Mobil 1 5W30 for the rest of the year and the rough idle gets better during the warmer months. The 5W30 causes a slight vibration in the steering wheel during the summer. I know that Mobil 1 (5W30 & 0W30) is on the thin side for a 30 oil. Should I try a thicker 30 oil like the German Castrol 0W30 or Mobil 1 10W30? Will this reduce my rough idle? [ August 02, 2003, 07:55 PM: Message edited by: MinnesotaNole ]
 
Messages
8,467
Location
Colorado
In my car, when I started to use the German Castrol 0W-30, the engine ran smoother at start-up and more quickly started running smooth. Once the engine is warmed up in runs smooth at idle with any oil.
 
Messages
23,591
Poor idle is usually caused by a dirty/defective MAF sensor, a dirty/defective ICV, a stuck EGR valve, worn/fouled/incorrect spark plugs, bad ignition wires, and most of all, vacuum leaks (vac hoses and gaskets). It's usually one or more of those...
 
Messages
661
Location
Ottawa, Ont CANADA
quote:
Originally posted by moribundman: Poor idle is usually caused by a dirty/defective MAF sensor, a dirty/defective ICV, a stuck EGR valve, worn/fouled/incorrect spark plugs, bad ignition wires, and most of all, vacuum leaks (vac hoses and gaskets). It's usually one or more of those...
I concure... oil is not the source.. Jean
 
Messages
764
Location
Fairfield County, CT
I've actually seen the opposite, a Honda Civic running 20W-50 (!) idled really rough (always), and when I switched it to M1 5W-30, it was MUCH smoother. Isn't M1 0W-30 actually thicker than M1 5W-30 at normal operating temp? I thought I read that here somewhere. Jason
 
Messages
43
Location
Middle Tennessee
Minnesota, I have a 93 Accord that also idles roughtly (110K mi.). Have run 2 auto-rx treatments through it, which did not help much. In addition to the other ideas suggested, it could also be the motor mounts (that's what my mechanic suspects). Is the problem rough idle or excessive vibration transmitted through steering wheel? That said, I have tried different dino oils recently, and the car seems to idle a bit more smoothly with Pennzoil 10w-30. I believe this runs a bit on the heavy side for a 30 wt. oil. I am considering Mobil 0w-40 at the next change. Would appreciate any comments on the use of this oil in a Honda engine.
 
Messages
1,902
Location
cali
my 91 accord ran rough. but then after an auto rx treatment it helped a little but at the same time it cleaned my engine =-)...though it was another problem i think. pcv, dirty throttle body and TPS was my problem, also i just had to re-adjust my idle as well. i changed/cleaned those out and now my idle is better...also my front and rear mounts were bad so that made it even better... i run dino 10w30 for the life of this car..great car. check ur motor mounts though...if the frotn one went out then the back one may be worse...i learned the hard way.
 
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