3.4l vibration at 1400 rpm only in neutral or park
#1
Registered User
Thread Starter
Join Date: Jun 2009
Location: Colorado
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
3.4l vibration at 1400 rpm only in neutral or park
Help...
1997 4Runner SR5, 3.4, auto, 4x4
Upon cold start the engine revs up to 1700 rpm and settles down to around 1400 and then finally down to 850. Well it has a nasty pulsing vibration around 1400 rpm. I can feel it in my seat, floorboards, and slightly in the steering wheel. If you open a front door and lay your hand on the outer edge you can feel it and even see it.
Put it in gear and it's gone. Put it in gear, hold the brake, and raise the idle to 1400 rpm and its gone. Its only noticeable when in neutral or in park and around 1400 rpm. Its driving me insane. I pried on the tranny mount and it made no difference. I've only owned it for 6 months and it has done it since day one.
Any armchair diagnosis? T-Belt off a tooth? Thermoclutch on the fan? Ignition? It does have factory wires . I drove a 99 today and it felt like it had noticeably more power. My wife drove it and she commented the same thing.
Any TSB's or patterns I should look into?
Thanks gang!
Jim
1997 4Runner SR5, 3.4, auto, 4x4
Upon cold start the engine revs up to 1700 rpm and settles down to around 1400 and then finally down to 850. Well it has a nasty pulsing vibration around 1400 rpm. I can feel it in my seat, floorboards, and slightly in the steering wheel. If you open a front door and lay your hand on the outer edge you can feel it and even see it.
Put it in gear and it's gone. Put it in gear, hold the brake, and raise the idle to 1400 rpm and its gone. Its only noticeable when in neutral or in park and around 1400 rpm. Its driving me insane. I pried on the tranny mount and it made no difference. I've only owned it for 6 months and it has done it since day one.
Any armchair diagnosis? T-Belt off a tooth? Thermoclutch on the fan? Ignition? It does have factory wires . I drove a 99 today and it felt like it had noticeably more power. My wife drove it and she commented the same thing.
Any TSB's or patterns I should look into?
Thanks gang!
Jim
#2
Registered User
Join Date: Mar 2010
Location: Fort Worth, TX
Posts: 227
Likes: 0
Received 0 Likes
on
0 Posts
I'm wondering if the flywheel could be off balance slightly? Since it only happens at that particular rpm, it would seem like it's something resonating. Try revving it to a higher rpm, try 2800, and see if it does it anywhere else.
#3
Registered User
Thread Starter
Join Date: Jun 2009
Location: Colorado
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Above 1800 rpm and I can't detect it. Less than 1000 rpm and I can't detect it. I'm hoping it's been like that since 1997 and I'm just being 'sensitive'.
Thread
Thread Starter
Forum
Replies
Last Post
Blamalam
86-95 Trucks & 4Runners
22
03-12-2022 07:34 AM
Shaun Crystal Gomban
Pre 84 Trucks
5
07-30-2015 10:13 PM
Seattle_Sign_Guy
95.5-2004 Tacomas & 96-2002 4Runners
0
07-12-2015 12:38 PM