Hello again!
Seems I've no luck lately. Today I've changed the oil in my T-bird after about 3500 miles. Used the same oil as ussual.
I started the engine and it's making a strange tapping sound now! It's audible while idling, not so audible under load (with gear engaged) and you won't hear it if slightly revv the engine up.
Any ideas what it may be? Shot bearings? :(
Thanks in advance for any ideas!
Mariusz...
Sounds like a valve. When you changed your oil you could have dislodged some varnish which is causing the valve to stick. May have to do another oil change/cleaning to remedy it further.
I know it has nothing to do with the oil change but an exhaust leak can make a similar sound. Eliminate the exhaust leak as the problem by listening to each cylinder at the manifold using a tube (or a stethoscope if you have it). If it's an exhaust leak you will really hear it when you get to the spot.
Good luck.
Do you think it may disappear or get quieter after a few miles of driving?
What are the differences between valve and bearings sound?
What are the symptons and sounds of bad bearing anyway? When the sound of shot bearing appear? Does it change with engine rpm? Would the oil pressure be lower with shot bearing? It would be good to know for future.
It sounds more like a rocker or lifter noise to me...my car does it after every oil change for a little while, then goes away. If it goes away under a load, I would doubt it's a bearing or an exhaust leak.
If you used a Fram (orange can of death!) filter, I'll bet ya that is the problem. Fram used to make a good filter, but now they are nothing but junk!
My wife thought she was doing me a favor last year when she took my '88 and had the oil changed, but the shop(?) used a Fram filter and you should have heard that poor 3.8 when I started it up. Needless to say that filter stayed on the engine for less than an hour after she brought it back!
I'm always using a German Knecht filters and never had any problems with them. Fram isn't available here.
I'll see how it is in the morning. Maybe it will heal itself?
If it will be still audible I'll record the sound and post it here.
a valve train noise from the upper half of the engine will make a sound similair in frequency to you taking a coin and tappng it on the fender of your car.
a bearing sound would be more agressive sounding than the valve train.
if its a v6,, there is a proportioning valve in the timing cover with a spring thing a ma jig. Ive often wondered about this piece part but no one ever talks about it getting jamed up. Maybe yours is, I would highly highly suggest you go to the parts store and purchase an after market oil guage. They are cheap. Remove your oil sending unit and screw in the fitting where the sender was. Start the car and take and actual oil presure reading before you jump to conclusions. I bought this kit and now it hangs on the shop wall as a tool.
A proportioning valve? What is it and what does it do?
I've changed the oil again today. It's been running on 5W30 and now I have Valvoline MaxLife 10W40 (American this time :)). The sound is still there!
I've visited my friend's engine and suspension shop. Three of his mechanics were listening to my engine and they dunno what it is! It's not a valvetrain for sure. It doesn't sound like bearing. Oil pressure is normal even on very hot engine.
Any ideas? Most guys suspect timing components... maybe a proportioning valve you mentioned? The sound is comming from the front center of the engine. Car runs strong and smooth as it used to.
There is one more thing I thought about today. I heard that sound before! After the previous oil change I could hear that sound if the engine lowered it's speed under 600/500rpm when cold, but than it was gone!
Now it's more audible under 500/600rpm, and not audible over 700rpm. It's almost gone on gear and you can't hear it while driving.
My description sounds like a riddle, sorry!
Do you have any good sectional view drawings of 1987 3.8 V6?
If you do, please e-mail me at: mariusz@lovefords.net
Thanks in advance!
Just get a 5.0/5.8 shipped over to ya. Problem Solved! :hick:
Do you know any volunteers to give me a nice V8 engine and pay for the shipping? :hick: :rollin:
Haha not really, I think money is all of our problem on this board. :hick:
Let's get back to reality. I like the 3.8 becouse of fuel economy. I don't need a fast car so it's great for me.
That noise is the main concern for me now. I dunno what's wrong, why it got worse after the oil cange?
It could be that your oil isnt high enough, but I doubt it. Specially after the oil change. I had a car that did that same thing and it ended up being a bad lifter.
Could be a sticky lifter - in fact that's what it likely is. When the oil was changed there would have been a brief moment when the car was first started that there would have been no oil pressure, and this may have caused a lifter to collapse. The noise might go away after some driving, or it might stay there forever. Regardless, if it's a noisey lifter don't be too concerned, as it won't hurt the engine.
Top end (valvetrain, including the lifters) noise can be identified because you'll be able to hear the individual "tap"s. This is because the camshaft and valvetrain only operates at half of the engine RPM. Bottom end noise is usually more like a rattle because it is double the frequency of valvetrain noise.
The "proportioning valve" that jcassity refers to is actually a pressure release valve, to prevent the oil pressure from going to high. If there is a blockage or somthing that causes the oil pressure to spike the valve is there to prevent you from blowing the oil filter off. It shouldn't cause low oil pressure. You've verified oil pressure is OK, so that's moot anyway :D
Another thing it could be is a front accessory or the belt that drives them. A chunk of belt missing can sound remarkably like an engine noise.
I'm placing my bets on a sluggish lifter, though.
Guess I'm not optimistic lately and thinking about the wrost. I'll have more free time now, so I better like to fix my car even if it's something serious. Is there another similar possibility that when there have been no oil pressure in the system for a short while one of the bearings that was slightly damaged before has polished the crank and the misterious sound got worse?
I'll take the serpentine belt off today to run the engine without the fan and will try to record this sound. With the fan running it's impossible to record it well.
Talk again soon!
The berrings usally get worse with higher rpm's. I doubt its that.
Finally I've taken the belt off and recorded a short video. I used "lifters additive" and the sound got worse!
Please let me know what you think. It sounds like trouble to me! I dunno what to do and noone knows for sure of what it actually is!
http://www.americangranada.com/pics/engine_sound.wmv
Do you have any ideas after watching the video?
I'm looking for some good drawings of the pre 1987 V6. Is there anyone in our group who has a 1986/87 Ford Shop Manual and could scan V6 part for me?
Thanks in advance!
Well it's hard to tell from a recording, but it sounds like a tinny kind of tapping noise which usually indicates valve train... And at any rate sounds like more than one to me. I used to have a 3.8 Buick V6 that did that when it was really hot because of low oil pressure...
Since the noise started after a oil change, I'd suspect the oil filter... It could be restricting flow, causing low pressure.
Has the oil pressure been checked???
BTW a good idea when changing oil, is to fill the filter before installing it. That prevents the engine from being oil starved(no oil pressure) while the pump fills the filter.
If you are talking about the knock after you let off the gas, it sounds like a connecting rod to me. Hope I am wrong.
Connecting rod bearing? Is it possible to replace them in 3.8 V6 without taking the engine out?
I haven't heard the sound as I can't download the file (curse this dialup hell), but if it is a rod bearing you're pretty much looking at a lower end rebuild, and this means the engine has gotta come out. It may be possible to do it in the car, but I sure wouldn't wanna try it. If the rod bearing is bad it almost certainly would damage the crankshaft. The crank would have to come out and be turned undersize in at least that one journal (provided it isn't worn below the undersize limit). Chances are you'd have to have the rod's big end redone as well.
Would anyone else that has heard the file say it sounds sort of like a diesel engine?
Actually, curiosity got the better of me and I downloaded it. It only took 45 minutes :D
It's very hard to hear, but if I'm hearing what I think I'm hearing I'm gonna have to agree with softtouch - that sounds like bottom end noise. And it does not sound healthy :(
I'm going to have to guess connecting rod bearing. It sounds like marbels in a tin can to me. Not a good thing:yuck:
The sound is kinda exaggerated becouse of codecs I used to change file size. Why this sound is gone if I change engine rpm from 600 to 650/700rmp? And why it's almost gone with gear engaged? The sound is also gone with the A/C on, becouse it's idling higher.
Can I check if it's a bearing using a stethoscope? Where would it be the most audible?
I have one more question. Is the 3.8 V6 using metric bolts?
Place your stechoscope on the oil pan - it should be most audible there.
The noise may go away at different RPM"s because the oil pressure comes up enough to cushion the knock.
Most of the bolts on a 3.8 are metric