Shuddering/Shaking Under Acceleration
Thread Starter
|
New User
Joined: Mar 2004
Posts: 21
Likes: 0
Shuddering/Shaking Under Acceleration
(1995 4.9L F150)
Well, I just resurrected the beast after about a year and a half of sitting. I replaced alternator, plugs, wires, cap, rotor and serp. belt and it pretty much fired right up.
I did an oil "flush" with some what I think is just basically ATF. I let it run for the recommended 5 minutes and then drained and chainged oil/filter.
So here's my problem: after taking it for a spin around the block I noticed a strong shudder/shaking as I accelerate. This mostly happens after it shifts to the higher gears (3rd/4th). If I got WOT, no problem....but once it shifts up, the shuddering starts.
Two other, maybe related, symptoms: after driving for 10mins or so, the valves get real noisy (sewing maching). Also, the oil pressure gague, which initially is reading ther perfect level for my truck, suddenly flickers and then just goes dead.
So I have a couple of theories:
1. Stuck valve(s)
2. Bad oil pump (although even when gague is dead, I look under oil cap and see oil being pumped up.
3. Water in fuel lines (tsk tsk, I just ran the year and half old fuel, just used some Seafoam)
4. Clogged fuel filter
Any help would be greatly appreciated...
JT
Well, I just resurrected the beast after about a year and a half of sitting. I replaced alternator, plugs, wires, cap, rotor and serp. belt and it pretty much fired right up.
I did an oil "flush" with some what I think is just basically ATF. I let it run for the recommended 5 minutes and then drained and chainged oil/filter.
So here's my problem: after taking it for a spin around the block I noticed a strong shudder/shaking as I accelerate. This mostly happens after it shifts to the higher gears (3rd/4th). If I got WOT, no problem....but once it shifts up, the shuddering starts.
Two other, maybe related, symptoms: after driving for 10mins or so, the valves get real noisy (sewing maching). Also, the oil pressure gague, which initially is reading ther perfect level for my truck, suddenly flickers and then just goes dead.
So I have a couple of theories:
1. Stuck valve(s)
2. Bad oil pump (although even when gague is dead, I look under oil cap and see oil being pumped up.
3. Water in fuel lines (tsk tsk, I just ran the year and half old fuel, just used some Seafoam)
4. Clogged fuel filter
Any help would be greatly appreciated...
JT
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
You may have some debris in the oil pickup that is partially clogging it or maybe the gasket between the pump and pickup has broken down and is no longer sealing, both of these will still get some oil into the motor but not enough to build sufficient oil pressure on the bearings. You're going to have to drop the pan and inspect.
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
Forget about the shudder for now it may be related to the oil problem or it may be something else, but if you don't fix the oil pressure problem ASAP you won't have to worry about the shudder because the engine will self destruct.
Thread Starter
|
New User
Joined: Mar 2004
Posts: 21
Likes: 0
@jpl...I'm using a Motorcraft filter on there now.
Paul, I agree...I'll definitely be getting down to that level soon, just more curious if those issues were related. I'm not looking forward to dropping that pan...such a PIA to do that.
One other question...if the oil filter got completely clogged from the loosened sludge particulates, does the system just bypass the filter alltogether and pump directly between the the valve train/crankcase? Could this mess with the pressure? As I said my gague is not always dead...only after the engine warms up and is under some good (uphill) load.
Jared
Paul, I agree...I'll definitely be getting down to that level soon, just more curious if those issues were related. I'm not looking forward to dropping that pan...such a PIA to do that.
One other question...if the oil filter got completely clogged from the loosened sludge particulates, does the system just bypass the filter alltogether and pump directly between the the valve train/crankcase? Could this mess with the pressure? As I said my gague is not always dead...only after the engine warms up and is under some good (uphill) load.
Jared
Thread
Thread Starter
Forum
Replies
Last Post
marmstrong2009
1978 - 1996 Big Bronco
3
Nov 29, 2009 08:23 PM
1995, 2002, 49, 50, 93, 95, accel, accelerate, acceleration, f150, f250, forum, shake, shaking, shaky, shuddering, thunderbird
