10641 rattle

Hi guys,
I bought a forterra 10641 recently, after a few days I could hear a rattle from inside the engine sump and loudest at the exhaust side. The dealer said work the tractor and listen to see if the sound gets worse or stay the same. Any ideas out there.
Patrick.

i'd drop the sump immediately to check out. a relative of mine had the same problem after rebuilding a truck engine, it turned out to be a loose main bearing cap. It could easily have catastrophic results.

If its a connecting rod bearing, it may run hot, break, and then the crankshaft rams it through the side of the block. I would check it out ASAP before it causes collateral damage and becomes 3 to 4 times more expensive.

I'm with Renze, dont use it until you have checked all the main bearing caps and play in the big ends.

but before you pull it apart do some tests to try to work out which caps to start looking at.
1. if it is a rumble under load it points to Main bearings. (will also have very low oil pressure when hot, you cannot go by pressure if cold)
2. if it is a tap tap tap it could be gudgin pin, worst at high rpm and no load. and no loss of oil pressure
3. If it is a knock knock knock, from idle up to mid RPM under most load conditions it would point to Big End bearing. (this is most likely) and you will also have low oil pressure when hot.

To test 2 and 3 above to locate which cylinder it is before pulling the sump off.....
1. Hold a big screw driver (or similar) with the handle in your ear and the point end against the side of the block just above the sump flange (if possible) you will hear the knock knock loudest when in line with the effected CYL. give or take.
2. Loosen the injector pipe on running engine (fast idle) on the cylinder you suspect, and check for a change in the knocking or tapping (big end will be quieter with no fuel, Gudgin may be louder with no fuel)
you should be able to determine which cylinder with some accuracy by this method before dropping the sump.

When draining the oil run it through a filter funnel and look for metal shavings (bits of bearing are non-magnetic)

if the oil is clean, it may be an easy fix, if the oil (or sump) is full of bits of metal then you will be in for a crank grind and complete set of new undersize bearings, and a new oil pump

with the sump off, first check play in the BE caps, starting with the one you determined above, if there is any play side to side or twisting remove the BE cap and check bearing and crankshaft condition (out of round limit is only 0.001", or 0.025mm) light surface scratching on the crank is ok, but it must be round!
Assuming Copper lead bearing shells are used by the factory, there should be no sign of copper showing through the thin layer of Lead (actually Lead-Indium alloy)

If there is no sign of play or ware in the BE look at the main bearings, first take off the main cap closest to where the noise was coming from, noting if the bolts are "tight"

Finally check the Torque on all cap bolts (as per setting in the manual)

Good luck, hopefully it is just a loose bolt!

Steve

the trick of loosening an injector line works spot on, but putting a screwdriver on it to act as a resonance bar, the outcome is mostly luck because the whole block resonates. Plus it gives you a headache when the screwdriver transmits the block vibrations to your skull when keeping it against it... I've heard about people doing so, tried it, but its an unreliable method and it gives you a headache...

Not sure, but is the UR3 oil pan part of the frame structure, or does it have a loose aluminium oil pan like a UR1 ??

To be fair the screw driver in the ear trick works well on otherwise nice quiet petrol motors, but, yes not so pleasant on a diesel! ........ Also takes something of a trained ear (to decipher the unusual clangings from the usual ones
you can get a proper mechanics stethoscope for the job (about NZ$50 at Automotive Parts stores here), i have never tried one, but i am told they work very well.

If all else fails drop the sump.

i had one engine (MK 2 Ford Cortina 1600) years ago that made a horrible noise, but it turned out to be a dent in the sump flange fouling the big end cap as it swung past.......... funny things can happen!

If all else fails drop the sump.

i had one engine (MK 2 Ford Cortina 1600) years ago that made a horrible noise, but it turned out to be a dent in the sump flange fouling the big end cap as it swung past.......... funny things can happen!

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Better be safe than sorry...

I got a mechanic to look over the tractor. We could hear the rattle after a minute after start up. He drove it out of the shed and reved it up a few times and the rattle went away. He could not find any vibration around the engine. Opened injector pipes one by one and no change in sound. Engine oil is clean, pressure is good on dash. Mechanic advised to work away and listen for noise to worsen or stay on constant. No pressure when dipstick is removed, exhaust smoke is normal. Power and performance is good.
Any more ideas.

look beyond the engine. is the fan hitting the shroud ? If anything else is excluded, you can look precisely.

Sounds a bit like a clutch rattle, ..... does it change when light or heavy pressure is applied to the clutch pedal?
I have had a Flywheel come loose before (not on a tractor) made a hell of a noise at idle, but went quiet under load or higher revs....... loose front pulley will do the same only not as bad.
Does it sound like it is at engine speed and regular (tap--tap--tap), or is it more of a chatter?
it will annoy you until you find it!

I had the sump off and I think the problem is the strainer on the end of the lubrication pump suction pipe. It is held in place by a spring and can dance around and move up and down with sump oil movement. Does anyone know if welding it solid would work and why does it have to float around on a spring anyway.

Probably because it was not unknown for the brazed joint between the filter pipe and the pump to fail on earlier 8011's

I had the sump off and I think the problem is the strainer on the end of the lubrication pump suction pipe. It is held in place by a spring and can dance around and move up and down with sump oil movement. Does anyone know if welding it solid would work and why does it have to float around on a spring anyway.

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Assuming it is wholy below the oil level, you would not hear it rattle as the oil will dampen and absorb all the noise.
unless it is JUST hitting the bottom of the sump.
i would keep looking!..........
did you drain the oil through a strainer funnel to look for bearing metal or other forign bodies?

I did have an engine with a broken piston skirt once........ made a funny rattle but nothing bad, when i stripped it down for parts the piston came out in 2 peices!

I did see a half a semicircle and a smaller circle engraved in the bottom of the sump under the suction strainer and of the same size as the suction strainer. The oil relief valve return hole is angled to fire oil towards the suction strainer if pressure was high enough. This could be what is causing the suction strainer to dance around and make the noise.

I did see a half a semicircle and a smaller circle engraved in the bottom of the sump under the suction strainer and of the same size as the suction strainer. The oil relief valve return hole is angled to fire oil towards the suction strainer if pressure was high enough. This could be what is causing the suction strainer to dance around and make the noise.

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Ideally the Strainer should be just off (5mm or so) the bottom of the sump (gives the sludge somewhere to lay) .... but not sure if the Zetor is designed this way.....
check the sump is not dented...... is it an Alloy sump like the 7 series UR1 or are the later ones using a Tin sump?

the pressure relief valve wont cause the strainer to jump around as it has to squirt through a sump full of oil, which will dissipate all the energy.

try running the engine with the sump off and see if it still rattles..... it makes a hell of a mess and you can only safely run it for about 30 seconds at idle speed, but you may see what is vibrating, or not vibrating........ use safety glasses to keep the oil out of your eyes!

The sump is cast iron. I can see where the strainer hits the sump. Why does the strainer have to be flexible and not welded to the suction pipe 5mm off bottom.

The sump is cast iron. I can see where the strainer hits the sump. Why does the strainer have to be flexible and not welded to the suction pipe 5mm off bottom.

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i cannot think of a "good" reason...... most likly somebody in the design department thought it was a "good idea" after a few beers on a friday night

i would fix it in place with the strainer 5mm off the bottom of the sump and the pickup pipe ~1 x "Dia of the pipe" off the strainer (never let the strainer get too close to the pickup pipe)
most pickup pipes are cut at 45Deg at the end so the strainer canot get sucked into the end and cause a restriction to flow.
(in this case set the tip of the pipe 5mm above the bottom of the gauze strainer)

Check also that the pickup pipe is not loose in the pump (or whereever it is attached on a 10641)
i have seen pickup pipes come loose and foul the crankshaft...... that makes them rattle!

Check also that the pickup pipe is not loose in the pump (or whereever it is attached on a 10641)
i have seen pickup pipes come loose and foul the crankshaft...... that makes them rattle!

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Typical on DAF 620 engines... you could count the occasions on one hand, but enough for our service department to check at every oil change by feeling through the drain hole...

I finally found the rattle. Its the valves in the compressor head. When the pressure gets up to near maximum just before the release valve opens, the valves start to rattle in the compressor head. A new head is around 100 so its not to expensive to fix.

Great to hear you've found the problem! Thanks for posting what you found. I have seen other compressors fail the valves before, and blow the pieces of them back up into the intake manifold and into the engine, so it may pay to not use the compressor until you get a new head on it

I have seen other compressors fail the valves before, and blow the pieces of them back up into the intake manifold and into the engine, so it may pay to not use the compressor until you get a new head on it

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Or at least disconect the hose from the intake manifold and fit an external intake filter if you need to use the air.