Volvo Penta 4.3GS Idle Rattle / Knock /// Water Tested ///

bjcsc · Jun 4, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Update: I had to order the cap and rotor so no report on that. Should have them by Thursday. I ran the engine at ~1200RPM,18" of vacuum, which is the slowest it will operate without making the noises, though I still hear one or two knocks every 3 minutes or so, but not like at idle. It will not idle at much lower than 1000RPM until it warms up. When it reached operating temperature, I slowed it to 900RPM to get the noises and tried to pinpoint with a stethescope. I could not find any area where it was louder than any other. I retested the compression per the Mercruiser bulletin. This is what I found:

#1: 146 #2: 150
#3: 150 #4: 145
#5: 146 #6: 145

This seems to be consistent with what I found before and logically what I would expect to see from a new (not reman.) engine with less than 4 hours on it. I also followed the procedure for the leakdown testing in the bulletin. I could hear no air coming from the carb. or the exhaust from any cylinder. On all cylinders I could hear a little at the oil fill cap, which the bulletin says is normal and is consistent with what I would expect from relatively new rings. I had two old oil filters as I changed the oil twice last week (initially suspected stuck lifter and thought it would help). The first was the original filter since minute one on the new engine. In the one half I examined I found ~8 small specs of green sealant and very few grains of something. This is far less than I would expect to see in a filter an engine was breaking in on. In the second filter, which was on long enough to bring the engine to temperature plus 10 minutes I found nothing. Although I am not a mechanic, I would find it very incredible if it was in fact a spun bearing or piston problem or dropped valve. This problem occurred during storage and I would associate all three of those problems with occuring while running. This boat's original motor dropped half of the #3 intake valve while underway, sucked it back into the intake and embedded it in the top of the #5 piston. It made one loud clank and immediately shut down. It wouldn't even run much less make any noises. It happened because there was a water leak in the intake that eventually tempered the valve. And although my plugs are not clean, I suppose that is something else I could check. I'm really at a loss here but am suspecting my ignition or valve timing more and more. Again, I do appreciate every one of your responses.

bjcsc · Jun 4, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

More testing. I removed the valve covers and watched the valves/rockers do their thing while I spun the engine by hand. None were sticking,slow or stuck. I then took the distributor cap off and noticed that when the balancer's TDC mark is aligned with the timing covers (#1 at TDC), the rotor is pointing in between #1 and #6. I would expect it to be between 1 and 2, does that sound right? I rolled it around again but this time stopped the rotor at the #1 peg in the cap. It was past the scale but ~18-20 BTDC. Any clues in this?

jimmbo · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Listening to the video, it would be normal if it were a diesel. I think you should pull the outdrive, check the u-joints and gimbal bearings, then pull the engine and check the flywheel and drive coupler for loose or missing bolts.

bamadave · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Just wondering out loud, when repowering, I'm thinking whatever caused the first engine to go MIGHT be causing the same thing on this engine. Was everything from the long block swapped over to this block except for the risers? Don or anyone else, would I be out of place to recommend a LITTLE Marvel Mystery oil to be poured down the carb while running.

lilmandavis · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

if the compression is good you need to find other possibilities. like just totaly remove the drive may have a busted u joint. something is really straining that baby and it aint goin to go away. theres no water on the plugs are there? are the plugs nice brand new shiny white? are are they showing normal running or fouled. hows the oil level? i like the oil filter surgery idea, that can tell you alot. use tin snips if you dont have the oil can opener. dont use a saw, as that will give you shavings, and if there werent any youd be bummed to find em. what did the last engine sound like when it went?

Mischief Managed · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Originally posted by bjcsc: More testing. I removed the valve covers and watched the valves/rockers do their thing while I spun the engine by hand. None were sticking,slow or stuck. I then took the distributor cap off and noticed that when the balancer's TDC mark is aligned with the timing covers (#1 at TDC), the rotor is pointing in between #1 and #6. I would expect it to be between 1 and 2, does that sound right? I rolled it around again but this time stopped the rotor at the #1 peg in the cap. It was past the scale but ~18-20 BTDC. Any clues in this?

Wow! sounds like the timing chain is really sloppy. Could account for the noise too. If it's really loose, it'll tend to knock around a bit more at low RPM when the valve springs will actually be able to spin the cam ahead faster than the chain, as the valves close, causing excessive slack in the tight side of the chain. At higher RPMs, the chain wills stay tighter since the valve springs will not be able to spin the cam faster than the chain can.

bjcsc · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Originally posted by lilmandavis: if the compression is good you need to find other possibilities. like just totaly remove the drive may have a busted u joint. something is really straining that baby and it aint goin to go away. theres no water on the plugs are there? are the plugs nice brand new shiny white? are are they showing normal running or fouled. hows the oil level? i like the oil filter surgery idea, that can tell you alot. use tin snips if you dont have the oil can opener. dont use a saw, as that will give you shavings, and if there werent any youd be bummed to find em. what did the last engine sound like when it went?

Hello. There is no water in the cylinders or on the plugs. They are not shiny at all, totally black and carbon fouled as stated. See above for oil filter analysis. The last engine sounded like someone hit it with a hammer one time and then it bogged and shut down. Apparently the intake had been leaking and sucking water enough water to temper the valves for quite some time, although I never saw it on the plugs. I had only had the boat for a little over a year at that point and I do not what the PO's maintenance standards were but I suspect poor. bamadave: Everything was swapped to the new long block including the risers and manifolds as they were only 2 months old when the engine went. The intake was replaced as it was suspect for the failure and the carb. and alternator were replaced with new. Remember I do not have an outdrive, I have a jet drive. All three bearings and respective seals in it were completely redone in 2004. However, that does not mean there isn't a problem with the drive coupler or flywheel components of the drive. It is not that intense to pull the impeller shaft so I guess I will do that and see what I see / hear what I hear. I have nothing to lose at this point and days before I get the cap and rotor. I will report back on the running minus the drive. Thanks everyone.

bjcsc · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Update: I pulled the drive. The end of the impeller shaft and the engine drive coupler look new. The engine ran the same...

bjcsc · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Next step: I guess I am going to pull the timing cover and verify that the chain has not jumped. If the chain jumped, would it cause what I'm seeing/hearing? Late valve timing seems pretty consistent with what my tests are giving me. I do have the manual and the procedure but would appreciate any tips from anyone who has done this on this motor before. Thank you all again.

Gary H NC · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Could the timing be off 180 degrees? I have been told they will run that way but with no power and sound like hell... It does sound like it could be the timing chain flopping around inside the cover..strange,,

newport dave · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Originally posted by bjcsc: Next step: I guess I am going to pull the timing cover and verify that the chain has not jumped.

Pulling the timing cover on that motor is a pita. You have to drop the oil pan to do it right. By the way there is a GM service bulletin for the addition of a timing chain tensioner on the 4.3. I did one last year trying to correct a knocking noise. Never did find it, owner sold the boat "as is". Dave

Dave

paulie0735 · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

I would not be surprised to find a lose flywheel, I agree with most of the posts above, don't run it unless you have to.

searay3 · Jun 5, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Could just be a bad bearing, probably rod. Had a rebuilder here that had a few failures. Prior to an istallation, we took one apart. There were hidieous mars on the crankshaft where they installed the rods without regard to the rod bolts (no pun intended rodbolt). Caused bearing failure after a short period of time in use.

Mile-High Mariner · Jun 6, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

bj - all of this diagnostic help is good, but have you thought to take up the matter with the wrench that did the longblock replacement? I would determine the source of the longblock, get some information on the reman and definitely find out what the marine service shop that performed the work is going to do for you under the present circumstances (I'm referring to warranty stuff, here). Now, by way of adding to the diagnostic melee, remove your spark plugs and turn the crank until you have Cylinder 1 at TDC. It's helpful to have two sets of hands for this - press on the top of the piston with a flathead screwdriver or something like it, and have your assistant turn the crank back and forth around TDC; what you're feeling for is delayed movement of the piston due to play in the connecting rod bearing. Rotate the crank to put each consecutive piston at TDC and check for play in each one. Don's comment got me thinking about spun bearings and the looseness that quickly develops in the journal after a bearing begins to fail, and your noise reminds me of an almost exactly similar noise produced by my 3.0L, except timed a bit differently due to the differences in number of cylinders between our powerplants. When you changed your oil, did you notice any metal in it at all? It might begin as a fine silt, then progress all the way to massive shavings right before the thing beats itself to pieces. Whatever you have, it's NOT going to go away, and is NOT an acceptable condition for a new or freshly remanufactured motor. I'd be willing to bet with Don S that you have one or more spun or otherwise failed bearings, and the knock you're hearing is the crankshaft banging around inside the ever-widening hole at the end of your connecting rod(s). Sorry, dude!

FreeBeeTony · Jun 6, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Did you check to see if the valves/rocker arms are adjusted correctly? Were they checked or assumed to be ok from the rebuilder. I would not go with the static adjustment. Adjust them while running. Just my opinion. How about the oil pressure? If it was bad/spun bearings, wouldn't the pressure be dropping when it warmed-up? Also, the vaccum seemed very low at idle.....any update there?

bjcsc · Jun 6, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

MHMariner: The long block swap was done by the VP dealer here. The motor was a new GM base engine whose warranty expired in September of last year while I wasn't using it. There are no warranty situations I could take advantage of. After reading through many related posts here, I have absolutely no doubt as to Don S's abilities and talent (wish he was in Charleston!) and you and he could very well be right about the bearings. I could understand it better as a possibility on a reman engine, as they are only as good as the person(s) who built them. I would and do have higher expectations from a new engine. However, improbable is not impossible. I also read that oil pressure and lack of it is what leads to spun bearings and bearing failures and I have not experienced this. I have a steady 40PSI+ at idle. Athough my opinion is really from a position of ignorance relative to all of you tech guys, it seems to me that a rod knocking or bearing seizing would get worse with higher RPM's and not all but disappear above a certain level. Check my previous posts regarding the oil filter analyses. BabylonBoater: The valves are not adjustable (hydraulic lifters - see above posts) The vacuum is still the same. According to DonS.'s link and my own service manual it means either late ignition or late valve timing. I verified the ignition timing and thus have decided to remove the timing cover and verify the valve timing. Additonally, most of the threads I have been reading while searching end with no resolution. I can't tell you why my engine is doing what it's doing, but I'll tell you this: when this thread ends, it will be with my boat having a normal running motor and what it took to get there.

bvh · Jun 6, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

In listening to it, it sounds to me to not be a single bearing or single piston as the source. One thing that stands out is you saying that the rotor is pointed at #1 at 18 to 20 BTDC. If it is firing all the cylinders that early, it would make a racket trying to run bakwards. This would indicate that it is really advanced, not late. Have you turned the distibutor while it is running to see if the sound gets better/worse? If it jumped time, usually the crank jumps, which makes the valves and ignition late. For everything to be early, either the cam jumped or it happened while running backwards. There is something fishy with the timing. Does it jump around while running or stay on the mark? Have you pulled the distibutor to check out the teeth? At one time there was an issue with distibutor gears getting eaten by the cam gear on 4.3's. Had to do with the material used on the distibutor gear. I would look into the distibutor and the timing chain idea. It sounds like for than a single source for the noise. Way advanced ignition timing could do that. Sorry to ramble...

bjcsc · Jun 6, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Update: bvh: I varied the ignition timing a good deal when I checked it to see if I could make any improvement. It had no effect. I pulled the distributor and checked the gear, looked perfect. I also pulled the timing cover to find everything as it should be. The valve timing is dead on. I do not believe there is anything else I can do/check before pulling this engine. Correct me if I am wrong. I have never pulled an engine before, although a marine engine is probably a great place to start. Pulling it out will be no problem as I have a hydraulic boom operated by the three point hitch and remotes on my tractor. I would appreciate some tips on attaching it to the stand (like attachment points, fastener size/pitch/length, what this engine weighs approx. in order to buy the right stand, etc.) and what you think the order of my examination procedure should be. What should I look for? I do not intend to disassemble the top end as I do not believe it to be part of the problem. Do you agree? Can an intelligent, detail oriented, mechanically inclined person armed with the service manual undertake this and expect a good result?

tommays · Jun 6, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

I would expect it to be between 1 and 2, does that sound right? I rolled it around again but this time stopped the rotor at the #1 peg in the cap. It was past the scale but ~18-20 BTDC. Any clues in this?

The TDC rotor on 1 thing you do have to go 2 compleat turns to get back to to TDC on 1 again There is no getting around a compleat tear down of the motor if your testing finds its a bearing or whatever All of the metal from a failed part will have gotten in to many places Once you pull the motor and remove the bellhousing it will bolt up to any motor stand tommays

FreeBeeTony · Jun 6, 2006

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

Re: Volvo Penta 4.3GS Idle Rattle / Knock /// FIXED! ///

The valves are adjustable........being hydraulic doesn't mean that they do not require adjustment.

Volvo Penta 4.3GS Idle Rattle / Knock /// Water Tested ///

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