93 Ford F-150 (302 V8) knocking.....
#1
93 Ford F-150 (302 V8) knocking.....
Several months ago I posted a question regarding my truck, and now, having finally followed through on the advice, I'll ask your opinions again. I've been driving the truck around town this way for almost 8 months now.
Having identified that the knock is perfectly in time with the spark going to the drivers' side rear cylinder, I took the truck to a local mechanic to see what he thinks it could be.
He immediately said it sounded like a rod bearing (which is what I thought in the first place). When you rev the engine, the knock stops just briefly, then rattles some more, but when it idles down to a certain speed, the knock will stop again just briefly, then when it reaches idle, it hammers pretty hard again.
When you crawl under the engine, it does sound very loud near the oil pan, down low like it would be the journal on the crankshaft. Is there anything else it could be? Piston pin? Broken skirt?
So I guess my question is... what should I do about it? A lot of people tell me just to get a different engine, since you have to pull the engine to work on it anyway. you might spend more for the engine, but it will save you the time of fixing it. If it can be repaired, what can I expect?
This truck cost me $4900 5 years ago, so I've definately got my money out of it. I guess at $1000 per year, one way I look at it is, if I put another $2000 in it, it better last me 2 more years! I'll be doing this myself with the help of a mechanic friend.
Having identified that the knock is perfectly in time with the spark going to the drivers' side rear cylinder, I took the truck to a local mechanic to see what he thinks it could be.
He immediately said it sounded like a rod bearing (which is what I thought in the first place). When you rev the engine, the knock stops just briefly, then rattles some more, but when it idles down to a certain speed, the knock will stop again just briefly, then when it reaches idle, it hammers pretty hard again.
When you crawl under the engine, it does sound very loud near the oil pan, down low like it would be the journal on the crankshaft. Is there anything else it could be? Piston pin? Broken skirt?
So I guess my question is... what should I do about it? A lot of people tell me just to get a different engine, since you have to pull the engine to work on it anyway. you might spend more for the engine, but it will save you the time of fixing it. If it can be repaired, what can I expect?
This truck cost me $4900 5 years ago, so I've definately got my money out of it. I guess at $1000 per year, one way I look at it is, if I put another $2000 in it, it better last me 2 more years! I'll be doing this myself with the help of a mechanic friend.
#2
I nearly always recommend to my friends to buy a remanufactured long block. Your old engine will be used as a trade-in to lower the price if you buy from a auto supply store, which few people realize, do sell engines.
#4
Both reasonable comments that agree with what others have told me. One other thing... my a/c compressor on this truck is shot. What are my options? It was freon back then, right? Do you have to switch those over now, or can you still get a remanufactured freon compressor?
#5
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you should be able to get a remanufactured compressor all a/c system uses freon the type of freon used could be r12 or r134a as most manufacturers switched around the 93-94 model year both types are still available although r12 is more expensive and you may want to switch to r134a if it is an r12 system.
#7
Thanks guys-
I believe it is r-12. So to convert it, all I have to change is the compressor? Do any fittings have to change as well? I've got a friend who can charge it, but new systems have to be evacuated or something, don't they?
I believe it is r-12. So to convert it, all I have to change is the compressor? Do any fittings have to change as well? I've got a friend who can charge it, but new systems have to be evacuated or something, don't they?
#8
You should plan on buying the accumlator, and orifice tube. And some flush solvent to flush out the lines. A new or rebuilt compressor only comes with enought oil in it to keep it lubed so you will need oil as well as r-134. And you need a vacuum pump to draw a vacuum (to remove all moisture) before you fill.