Hi guys. I've had an 83 5.0 Thunderbird for the better part of a year now. The car generally runs quite well but there are some nagging problems that I'd like to track down. For starters there's the knock. Only comes up after the car warms up like 10-15 minutes into the drive and is mostly noticeable when the car is stopped at a light. I really don't know the difference between a rapping, tapping, knocking, ticking, or a saxophone...is there a site where I can listen to those sounds? Around the same time the knock shows up so does the "Engine" light. Also dormant until I stop somewhere. It tends to flicker lightly but can come on solid if I do any intense driving like on the highway and eventually it can stick on entirely. The knock also increases in intensity on the highway. I've heard all sorts of explanations for these but I wanted the opinions of people who actually have the same car. I'm planning to replace the lifters and head gaskets this weekend. It may not have an effect on the noise but I feel it's worth doing. And something else that doesn't bug me quite as much but bugs me enough is this steady light sing/grinding noise I get. It doesn't show up at idle until I give the car a little gas and then there it is. I normall can't hear it from inside the car unless I pass by certain objects and it echos back to me. Oh and I don't know if this is relevant to the problem but the car vibrates quite a bit when stopped. Also the knocking and Engine light problems don't surface in the winter. Any insight from you guys would be helpful, I know I've typed up quite a post here. Thanks.
try the thermostat and check your idle speed. My freinds car had the same problem. His car was overcooling in the summer and that can cause the car to idle low sometimes. It could also be your idle speed or timing.
I actually replaced the Thermostat and the radiator not long ago. It didn't make a difference. As for the idle and timing I think the mechanic adjusted those when I had the carburetor replaced. Lol. I'm intrigued though, what exactly causes overcooling?
Well actually I guess I don't know if the idle speed was really adjusted. They told me they adjusted the timing. Maybe I'll mess around with the idle this week and see what it gets me.
overcooling is when the t-stat opens premeturly. It is when the engine temp is too low.
I see. Well I'm pretty sure I put in a standard 180 deg thermostat. The previous one was broken in pieces when we found it so it may have been a problem but shouldn't be now I don't think. As for the idle speed I'm aware of how to adjust it but do you think I want to go up or down? I've had comments from people before that my idle seemed high so I'm thinking down is the way to go. Trial and error I suppose.
Is your 83 equipped with a carburetor or a CFI (Central Fuel Injection)
There is a number of items that could be causing what you are describing. If you have had carburetor work done, I would look at the vacuum lines make sure there all connected. Have your timing checked before doing any carb work. The timing on the 5.0L should be 10 degrees BTC. Point of concern, if your carb was adjust prior to timing, this could effect your timing causing high idle speed when stopped at a light or engine missing at hiway speeds. One should set the timing before doing any carb work not doing this could cause your "engine light" to come on due to increased emissions.
The grinding noise you are hearing is most likely coming from your drive train or brakes.
Sounds to me like low oil pressure....esp if the light comes on once the car warms up, or at idle.
Sounds like you have more pressing issues than v/c gaskets and lifters.....
I'm getting that knock now and I wasn't getting it before, and now I'm showing as low as 6-7 PSI oil pressure at warm idle under load.. where before I was getting at least 12-13 under the same conditions. I'm thinking my oil change experiment was a bust, and now that it's getting into the 90s down here I might need to use something a little bit thicker than what I used this time. (4 quarts of MaxLife 5w30 and 1 qt. MaxLife Synthetic 10w30)
The timing was actually adjusted prior to replacing the carburetor because I originally went to the garage for a tune-up and on their recommendation I went ahead with the new carb. There's some evidence that the car has TBI but I haven't gotten under the carb to find out. I've been told I may have low oil pressure, I plan to have it tested one of these days. As for the point of it doing this at idle, it only does it when in gear. Shift to park and the problem is gone.
I've actually tried using a straight 30W oil to quiet the knock but it didn't do anything for me. That's what's in there now but with the work I'm about to do I bought some Quaker State Advanced Engine full synthetic to put back in. Can't hurt to try.
I'm thinking of MaxLife 10w30 with a quart of MaxLife Synthetic 10w40, or something along those lines.. for this oil change only. I want to try to limit the MaxLife use to once a year. Some have said if you use it all the time and then switch to something else, it'll dry out the seals its meant to swell up.. but that once a year should be fine. (of course, almost none of this stuff is proven, and is chosen about as scientifically as what beer we choose to drink)
check vacume hoses
If your bearings or oil pump are that shot...no oil mixing voodoo is going to solve the problem. Start saving for an engine rebuild..... You're on borrowed time.
Who said anything about a 3.8 rebuild, while I still have a perfectly good carbed 351W sitting around..? :evilgrin:
My comment was more directed at the thread starter...
His engine will be a good boat anchor in short order....
Well, I was the one talking about "oil mixing voodoo". :p
(which, btw, I was not recommending in any way to this other guy)
K I took a stab at adjusting the idle speed. I had thought I knew how to do it but the screw I adjusted didn't seem to have any effect after like 10 half turns. If you look at the attached picture it's the long one near the bottom with the spring. Am I missing something? I have the Chilton manual but the section on idle speed is three lines saying it's done by computer. Computer? :bs: Thanks Chilton. The other thing is that talk about vacuum lines led me to wonder about the EGR valve (other picture). Once again Chilton wasn't helpful, it explained the different types of EGR used over the 14 YEARS!! of cars the manual covers. Barely even a helpful picture. I found it anyway but I'm confused about where the valve ends and the distributor begins. Is the saucer shaped piece all there is to it? It does have screws and can apparently be removed but I don't want to end up removing half the valve. Some pointers would be really helpful. Thanks.
Actually that plunger thing is secured on the other side by a bolt in a "sliding" hole. Should I loosed that before I turn the screw?
In some models/engines/countries (or alternate universes), the idle is controlled by a little electric motor and plunger, instead of the manual-adjuster you have.
Yes.
The big can assembly is the "Throttle Modulator with Dashpot", which is mounted in the idle "saddle". Loosen the lock bolt, otherwise you'll just be twisting the saddle sideways (or twisting it into ).
Here's the idle procedure from my Haynes "Mid-size LTD" book, that shows the same kind of adjuster (the T-Bird book doesn't):
1. Place the transmission in Neutral or Park and firmly set the parking brake. Turn the air conditioning selector to the Off position.
2. Start the engine and let it run until it reaches normal operating temperature.
3. Shut the engine off, then restart it and and run it at 2000 RPM for 60 seconds. If the vehicle is not equipped with a tachometer, attach an external one according to the manufacturer's instructions. Return the speed to idle and allow the engine to stabilize for 30 seconds. Bring the engine speed back to 2000 RPM and let it stabilize for approximately 10 seconds.
4. Place the transmission in Reverse. Check and adjust the curb idle speed within 60 seconds. If adjustment is required, loosen the saddle bracket locking screw (see accompanying illustration). Turn the adjusting screw clockwise to increase the idle speed or counterclockwise to decrease the speed until the specified RPM is obtained (see the Emission Control Information label for specified idle speed).
5. Tighten the saddle bracket locking screw and repeat the idle stabilization procedure in Step 3 to verify the final setting.
And here's a picture I used for another similar post:
(http://www3.telus.net/neat/pics1/idle.gif)
yeppers. that would be my first stop.
Obviously he has him fingers stuck in his ears and yelling "LALALALALALALAALAL I don't hear you!!! LALALALALALA" about that.....
It could be a bad oil pressure sender that is causing the light to come on...but with it knocking, I doubt it. Oh well, make sure you get the TV rod adjusted right so it's running well when the motor locks up :D
:flip: I'm not oblivious Chuck. I suppose if I told you to go get a rebuild you'd pull 3000 bucks out of your pocket and go do it? I'm gonna get the pressure tested this weekend and if that's the problem well I'll se together some cash to try and replace the pump with a high pressure one and hope that does the trick. If not...well I don't know.
Well, if it was knocking I wouldn't be driving it..much less at freeway speeds.
As far as the rebuild price goes....bah! You could do it yourself for less. Also, another alternative would be to locate a good longblock and swap that in. This might be a good option if this is your only car and funds are low. Could be something you could accomplish over the course of a weekend with the help of a friend or two....
Replacing the engine may yet be an option if I can find a good one. We'll see what happens over the course of the summer. As for driving it, it is my only car and I've been living with that knock since I bought it so you know...in any case I don't normally drive on the freeway.
After giving it some thought and considering how many things need fixing on the car I've decided the best thing to do is go to the local yard and grab another engine cheap that I can rebuild over the summer and drop in. The engine is tough I'm sure it'll last a while yet. Would there happen to be a database anywhere that tells you what cars use a particular engine? 302s are widely used among Fords, I know Mustangs used them, and some trucks I think. Since the yard does't have a directory of parts I want to know what to look for.
http://car-part.com/
Thanks for the link, that helps.
Quick question, since most 302s after mine were fuel injected that may be what I end up with. Is switching the intake manifold all there is to changing fuel injected to carbureted or is there more to it than that?
from efi to carb you need to swap out the intakes, and i believe the timing cover too if you have a mechanical fuel pump....
If you could find one with around 50,000 on it you could run it without rebuilding it and save up for an incredible rebuild. :)