engine knock (1 Viewer)

Joined
Apr 3, 2004
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64
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Flagstaff, Arizona 7,000 feet
Hoping someone out there with more knowledge than me can lend me some advice. I bought my FJ60 cheap because it had a knock. A friend of mine who has been a professional mechanic for several years pulled the pan and said that we can replace the main bearings and the camshaft and fix the knock. Anyway, after sitting in his shop for 5 weeks I handed him $2,000 and he said it runs great, fixed but the slight knock you hear now is from a tooth missing from your transmission. I believed this because when the clutch was in and I reved the engine, there was no knock. In the last month, 300 miles since repair, another friend said that it wasn't possible that the tranny would make such a noise and after he drove it he thought the rod bearings are bad. I told him it isn't loud when its cold and he said definitely. My question is: Does this sound reasonable? Why would my mechanic friend miss this? Is he lying to me when he says its a transmission noise or did he just not know and how easy is it to change the rod bearings? I love the truck but have already put $2,000 into an engine with 200k on it. Any advice out there?

Thanks
Mark
 
Joined
Sep 8, 2003
Messages
5,355
Location
Bozeman, MT
A mechanics stethascope should help you locate the knock from under the rig. It may give you a better location of the sound.

Just my .02

Drew <><
 
Joined
Jun 13, 2003
Messages
2,810
Sounds like your "friend" does not know what he is doing! 2K for mains and cam is way too much and is a poor way to fix it. I charge $1800 to rebuild the entire motor! Most all knocks from F series motors come from the rods. Usually, not always, crank bearings do not knock and eventually sieze in place.

Replacing the cam without the replacing the cam bearings and lifters is a waste of money. the cam cannot cause any type of knock. A very worn cam will cause running isues with the ignition. A new cam requires a new cam and crank gears.

To replace mains without replacing rods is a waste of money. To replace mains or rods without without polishing the crank bearing journals is a waste of money.

The expense of rebuilding a F series motor is low enough that a "in place" rebuild is not worth it.

Sounds to me that you have a rod knock. It will not knock as bad, now, when you depress the clutch as there is no tension on the crank from the transmission. Eventually it will knock all the time clutch or not.
 
Joined
Apr 3, 2004
Messages
64
Location
Flagstaff, Arizona 7,000 feet
thank all of you so much for your help. At this point would you recommend a new used engine or have my friend make it right by putting rod bearings in? I have seen what seems like a good deal from rising sun engines for $1,200 with guarantee.

Mark
 
Joined
Mar 12, 2004
Messages
688
If you told him specifically to only change the mains and cam and you paid $2k for the work, it would be unfortunate for you. It would be as if you were a contractor ordering certain work done. In which case, if you misdiagnosed the problem it would be your fault.

If however, he knew you bought the cruiser on the cheap because of the engine knock. He had been a trade professional and then offers to repair the motor based on his diagnosis. If his is work then fails to repair the motor, he should, as you say, "make it right". Why would you think of buying another motor at this point, when you're already in the hole for $2k and can pursue a remedy?
 
Joined
Apr 3, 2004
Messages
64
Location
Flagstaff, Arizona 7,000 feet
good point but am not convinced after all I've been through that he will be able to fix the rod bearings. Does it just involve pulling the oil pan or is it more involved? If I went to a shop to have the rod bearings alone changes, what do you think I should expect to pay?

thanks again

Mark
 
Joined
Mar 12, 2004
Messages
688
Technically, rod bearings can be changed from the bottom. But is it a good idea? Re-read David's post above. It has been done, and it's as shade tree a "rebuild" as there is.
 

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