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Polaris Engine Knocking After Maintenance???

31K views 20 replies 8 participants last post by  Russ C 
#1 ·
We bought a 2002 Polaris Magnum 325 4x4 and before riding it I did all of the maintenance on it. The full list of items include:

-oil/filter change
-spark plug
-air filter change
-fuel filter change
-hub, front diff, transmission and rear diff fluid
-drive belt

Everything was OEM Polaris including the oil and spark plug. Right when we got it we tested to see if it ran and it ran perfect and quiet. Now after all of the maintenance there is a horrid metal to metal knocking sound. I want to know what I messed up while doing routine maintenance? It wasn't hard at all after figuring out which fluids go where. I took a few videos to show the knocking sound.

The first video is from a cold start after sitting overnight. The middle videos progressively go as the quad heats up. The lasts 2 are with the quad fully warmed up and after going for a few minute drive and not shutting it off.

Any suggestions where to go from here? Polaris says it's normal but I'm sure it's no supposed to be that bad. The worst part is we know the knocking wasn't there before the fluid/belt changes.











 
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#4 ·
Not sure on the miles since no odometer/hour meter. It honestly looked really clean though with no rocks jammed in anywhere and no bushes stuck to anything. It could be possible that there was thicker oil in it before. It was definitely more viscous than the new oil but nothing outside of the ordinary differences between new and old oil.
 
#6 ·
this sounds to me like your lower connecting rod bearings are going out,caused by running the engine low on oil.this engine was known for wearing out the lower connecting rod bearings when running low on oil.the lower connecting rod bearing are not really bearings they are just two shims.when i worked for the polaris dealership here as the lead mechanic there was a service bulletin on the 325 magnums,the bulletin was to remove the H valve from the oil cooler lines,this H valve had flow and restriction issues and is not needed.to check if your H valve was removed follow your oil line from the front of the engine to the oil cooler,if the H valve is there than it should be in between the engine and the oil cooler.if there is a solid oil line all the way to the oil cooler than the service was performed,if not have it done before running the machine anymore.you are still going to have the crankshaft and lower connecting rod worked on.
 
#7 ·
^^I couldn't see any valves in the oil lines. Maybe the recall was already done on this one. What I don't understand is what could have happened during the changes to all of a sudden make this knocking sound. With some google searching people said that clutches with new belts would make a tapping sound. They also said it would go away if you moved the plastic shield around and my sound does not go away.

Here is the oil level of the quad as it was before even starting the quad for the first time







I also washed the quad while it was apart so maybe water got in somewhere?? I made sure to stuff a rag as far as possible into the intake.






I disconnected this oil line and blew it out with an air gun as well. The pressure didn't go through the engine and the air came right out of the oil filter area while the filter wasn't on. I didn't do the other oil line.



One other issue is the quad dies while going into reverse if I don't hold the button. Can someone identify the connector which is at fault from the following picture?
 
#8 ·
Someone please correct me if I am wrong, but I think these are air and oil cooled. Not water cooled, AND it seems to me that somewhere on the forum I read that when doing an oil change that you must purge the oil cooler and lines and oilpump of any air that was introduced during the oil change.

IF this is correct, it could be the source or cause of the knock.

Someone chime in on this subject.

NSX: Do a search on this and see what you get.
 
#9 ·
Thank you for the suggestions so far and more are welcome.

WalterS, this quad is air and oil cooled only. From my searches on changing oil it seems like only quads with the external oil tank and the screen have to purge. I didn't find any information about purging my type of engine as it doesn't have an external tank; just the drain and fill at the engine plus oil filter.
 
#10 ·
is the cooler getting warm when you run it can you tell if there is any oil flow.is the oil filter full of oil? doesn't make any sense that it wasnt knocking then you changed the oil and now its knocking.sounds like who ever had it before may have put some oil additives in it to quiet it down to sell it.
 
#12 ·
is the cooler getting warm when you run it can you tell if there is any oil flow.is the oil filter full of oil? doesn't make any sense that it wasn't knocking then you changed the oil and now its knocking.sounds like who ever had it before may have put some oil additives in it to quiet it down to sell it.
As far as I can tell it is getting hot even when stationary. I will run it tomorrow and confirm. We were also thinking that it might have been some additives the previous owner put in. Who knows though. Additives seem like a stretch.

after listening to your video and seeing the oil level before the oil change the oil level is to low causing the lower connecting rod bearings to wear out.i am just rebuilding a 2000 325 4x4 and a 1999 325 2x4 both with the same lower connecting rod problem.on the 4x4 i have to change the crankshaft and connecting rod and lower bearings.on the 2x4 i have to just replace the lower connecting rod bearings with the next size up .05 and clean up the connecting rod lower pin.this requires complete disassembly and rebuild of the motor.the 4x4 has to much damage to lower crank rod pin.
The oil level pictured is the oil level currently (after the oil change). It is in the "safe" region according to the dipstick. Should it be above the safe region?

So far it looks like all signs point to the rod bearing. I found an entire parts quad here with a running drive train for $400. I might just run this engine into the ground and then replace it with another one. That idea is instead of spending money on individual pieces which might end up costing more than the parts quad.

This whole situation just plain doesn't make sense. It's a simple 4 stroke engine.
 
#11 ·
after listening to your video and seeing the oil level before the oil change the oil level is to low causing the lower connecting rod bearings to wear out.i am just rebuilding a 2000 325 4x4 and a 1999 325 2x4 both with the same lower connecting rod problem.on the 4x4 i have to change the crankshaft and connecting rod and lower bearings.on the 2x4 i have to just replace thelower connecting rod bearings with the next size up .05 and clean up the connecting rod lower pin.this requires complete disassembly and rebuild of the motor.the 4x4 has to much damage to lower crank rod pin.
 
#13 ·
Some more information to go on. I put most of it together today just to get the plastics off the ground.

I found the ignition coil broken right at the spark plug. My idle was a bit erratic so a new coil will probably fix that problem. For the reverse stalling issue I disconnected the black wire at the reverse speed limiter box and now everything works fine. For the engine knocking I found something interesting. When sitting on the quad looking down at the airbox there is a hole to the left of the filter and a little bit above. This hole is pushing a lot of air out. It should be a vacuum most of the places in the airbox (unless you have a turbo). If anyone can see if their hole is pushing or sucking that would help me out.



Other options I was thinking of is maybe they gave me the wrong filter. I attached a picture of the part number they gave me. I no longer have the old filter. If someone works for Polaris can they verify I have the proper filter? I questioned the Polaris dealership I bought it from and "they don't make those kinds of mistakes"........no further comment.

Thanks for everyone who has suggested things so far.

 
#16 · (Edited)
We pulled the "out" line off the oil cooler and bumped the starter. Oil came shooting out with authority. We suspect the pressure is good.

Yes , you don't purge unless it has an external oil tank, does the oil filter warm up after running it a while, that would tell you if the oil is circulating.I personally don't think thicker oil would quiet that sound down, not to sound rude but did you put engine oil in the engine, not the trans fluid?
Double checked but just to make sure I put oil into the dip stick hole on the left front side of the engine. When we bumped the starter with the oil line off it would appear as if oil is circulating. I'll idle it for a very long time today and I will see if the cooler gets hot.



I took it to two Polaris dealers here and one of them said it was the valves (very young guy) and the other dealer said it sounded like every other Magnum he has heard (older guy but still wearing coveralls). He said it was a bit louder than usual though. For now I just put the rest of it together. The oil pump is working, it is the correct filter and there is oil on the dip stick. I'm going to take it out for a weekend and beat the hell out of it. We'll see if it gets louder. If it doesn't then I'll just drive it like it is until total meltdown. Then I'll just put a different engine in.













Don't mind the seat in the pictures. It's still "forming" to the new foam.
 
#15 ·
Yes , you don't purge unless it has an external oil tank, does the oil filter warm up after running it a while, that would tell you if the oil is circulating.I personally don't think thicker oil would quiet that sound down, not to sound rude but did you put engine oil in the engine, not the trans fluid?
 
#17 · (Edited)
I just picked up the same exact quad other day, mine has the same "knock", loudest at idle, appears to me coming from the lower left side, possibly from the clutch?, also compared to my Xploder 300 you have to rev the engine higher to engage movement, is this normal with a 4 stroke model?, or is the belt maybe thin causing the higher rpm engagement?

Found out the right front hub wasn't engageing, they had heavy oil/like marine lower end grease in the hubs!, the armature was stripped, luckily had a good used one and cleaned up the hilliard, the rollers were seized in and had to bend out the "forks" of the hilliard to get the rollers to move, also the wire to the hub was cut from the rim rubbing, i soldered the wires back and heat shrinked them and tie straped close to knuckle.

I got it free in exchange for services, just got rid of a knocking bayou 400, now inherited another, how did you ever make out?
 

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#18 ·
^^We just ended up leaving ours. We still have the same knock but looking at videos on Youtube all of them seem to have this knock. We decided not to worry about it. If the engine goes then we'll deal with it then.

As for the high RPM engagement I couldn't tell you. Ours feels "normal" for a belt driven system but we did put a new belt on this season.
 
#19 ·
I also have 2002 Magnum 325 I purchased new. It has had a knock since day 1 the dealer said it was normal so I just drove it. I have passed it down to the Grandchildren and it still going fine.
 
#20 ·
Talked today to the guy i got it from, he said since he had it knocked, and they rode it pretty hard for a few years, so i'm not gunna worry about it, noticed there is a recall on the oil cooler lines, mine appear to be leaking near the engine where the line is crimped to the rubber seeping down on the front driveshaft, anyone know if Polaris will still honor a 10+ yr old recall?
 
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