Long time reader, first time poster. I really appreciate this great forum!
I am familiar with car engines and have been working on V8's and other engines for several years.
Ok, here we go.
Bought a 1997 Regal 2150 with a VP 4.3 and a Cobra SX outdrive. The boat had been standing around for a couple of years and previous owner had it in the salt water and ran it with a small leak from the seawater pump. Guess you can all imagine what the engine and components looked like. I got all the accessories freed up and replaced the sea water pump. Removed water from the tank and gave it some fresh fuel and filter. It fired up and ran pretty good with muffs attached. After some testing I decided to take it to the lake and it was successful. Cruised around for a couple of days, guess I put about 8 hours on it with different speeds, but never held the full throttle for longer than 15 sec. One day I had to pick up some friends to bring the across the lake, I let it run (it was already at operating temp of course) at full throttle for about 6 - 8 minutes and I felt it lost some power and changed caracteristic. Let off the throttle and could hear a ticking metallic sound. Well, I picked up my friends and we had a 25 - 30 minutes ride at about 25kt. The sound was not possible to hear at higher rpm's and it pulled OK.
Got back home (another 30 minutes) and pulled it on the trailer. Then over to the diagnostics... I've been working on it for several hours today, of course after reading and watching videos. It sounds like several "sticky valve/lifter problem" videos available on youtube.
When removing all spark plugs the sound is barely noticeable
When disconnecting the distributor and leaving spark plugs in engine I can hear the sound, especially with the valve covers off. Localized the sound to be from cylinder 1.
When removing rocker arms and pushrods (only for cylinder 1) and running the engine the sound is not there. I can hear the cam smacking the lifters, but it might be normal.
Reassembling the pushrods and rocker arms the sound is not there until the engine has been running for like 2-5 minutes - strange!
Leaving the cover off I let the engine run and slightly back off the nut on the rocker arm (either one of them, intake or exhaust) there is no change - BUT when I tighten it it will remove the sound almost instantly. It will then return after 2-5 minutes of idling.
I'd like some input from you guys! My thoughts are:
1. Something loosened up and got into one of the lifters when running full throttle. Although this does not comply with the tightening of either exhaust or intake rocker arm since it does not matter which of them I tighten)
2. When I tighten the nut I relieve pressure from the piston since it might keep the valve a bit open until the lifter settles and the again fully closes the valve. Strange that it should completely remove the sound.
Also - could you please confirm that this engine does NOT have any kind of valve adjustment other than actually replacing the pushrods to a different part nr (with different lengths).
I put some ATF oil in the motor oil and ran it for some time and then changed it out including the filter.No change in sound.
Big thanks from Norway to whoever that can give me some good input to the problem.
I am familiar with car engines and have been working on V8's and other engines for several years.
Ok, here we go.
Bought a 1997 Regal 2150 with a VP 4.3 and a Cobra SX outdrive. The boat had been standing around for a couple of years and previous owner had it in the salt water and ran it with a small leak from the seawater pump. Guess you can all imagine what the engine and components looked like. I got all the accessories freed up and replaced the sea water pump. Removed water from the tank and gave it some fresh fuel and filter. It fired up and ran pretty good with muffs attached. After some testing I decided to take it to the lake and it was successful. Cruised around for a couple of days, guess I put about 8 hours on it with different speeds, but never held the full throttle for longer than 15 sec. One day I had to pick up some friends to bring the across the lake, I let it run (it was already at operating temp of course) at full throttle for about 6 - 8 minutes and I felt it lost some power and changed caracteristic. Let off the throttle and could hear a ticking metallic sound. Well, I picked up my friends and we had a 25 - 30 minutes ride at about 25kt. The sound was not possible to hear at higher rpm's and it pulled OK.
Got back home (another 30 minutes) and pulled it on the trailer. Then over to the diagnostics... I've been working on it for several hours today, of course after reading and watching videos. It sounds like several "sticky valve/lifter problem" videos available on youtube.
When removing all spark plugs the sound is barely noticeable
When disconnecting the distributor and leaving spark plugs in engine I can hear the sound, especially with the valve covers off. Localized the sound to be from cylinder 1.
When removing rocker arms and pushrods (only for cylinder 1) and running the engine the sound is not there. I can hear the cam smacking the lifters, but it might be normal.
Reassembling the pushrods and rocker arms the sound is not there until the engine has been running for like 2-5 minutes - strange!
Leaving the cover off I let the engine run and slightly back off the nut on the rocker arm (either one of them, intake or exhaust) there is no change - BUT when I tighten it it will remove the sound almost instantly. It will then return after 2-5 minutes of idling.
I'd like some input from you guys! My thoughts are:
1. Something loosened up and got into one of the lifters when running full throttle. Although this does not comply with the tightening of either exhaust or intake rocker arm since it does not matter which of them I tighten)
2. When I tighten the nut I relieve pressure from the piston since it might keep the valve a bit open until the lifter settles and the again fully closes the valve. Strange that it should completely remove the sound.
Also - could you please confirm that this engine does NOT have any kind of valve adjustment other than actually replacing the pushrods to a different part nr (with different lengths).
I put some ATF oil in the motor oil and ran it for some time and then changed it out including the filter.No change in sound.
Big thanks from Norway to whoever that can give me some good input to the problem.
