[TheOtherLeft]

Hiya all,

I'm experiencing a recent problem with my J20A that started about 1 week ago.

I get a random rattle when the engine is underload, ie accelerating up a hill. It lasts a few seconds.

I changed my oil about 2000km ago and also used an oil flush as I have had the timing rattle a while ago (maybe a year or so). This new rattle doesn't sound like the timing chain rattle which only occured at start up from cold. It sounds lower in pitch.

I don't get the new rattle all of the time only randomly and not every time when underload. There is no loss in power or increased fuel consumption or anything else that may suggest any problems, just the rattle. In fact it seems to be very responsive over the past several months. The Check Engine Light isn't on.

Any ideas please? Could it be valve clearance related? Would that reduce power? My engine has done 142,000km and I'm about to change the spark plugs, although I don't think it's plug related.

[fordem]

I don't see valve clearance as causing an intermittent & underload rattle - that engine has hydraulic lifters and if you're going to get lifter noise it's most likely to occur at a cold start.

My first suspicion would have been detonation, but you say "lower in pitch", so I'm thinking not so likely - what about the engine shifting slightly underload, causing an exhaust rattle or similar?

[christover1]

My Vit had a similar issue.
One bolt was missing, the other loose, on the CAT.
Took some finding, sounded like Engine was going to fall out.

[TheOtherLeft]

Here's a video I took. Note the engine is warm.

J20A video

I've now noticed it happens from about 2000RPM - 2300RPM. It's louder when the engine hasn't been run for a while (30min maybe but not necessarily cold) and reduces when it's been warmed up.

[lump_a_charcoal]

What fuel do you use? Mine used to make a light rattle, which, I found was due to pinking. I switched to premium and it stopped.

[TheOtherLeft]

It sounds worse on the video then in real life.

I use 91. Maybe i should try running 95 and see how it goes?

[atari4x4]

TheOtherLeft wrote:

It sounds worse on the video then in real life.

I use 91. Maybe i should try running 95 and see how it goes?

[TheOtherLeft]

I've been running 91 for months and the noise has only started happening so I didn't think it could be pinging, unless it's somehow weather related as well.

[atari4x4]

sure it's not just a batch of poor quality fuel... you still buying the cheap no brand fuel?

[TheOtherLeft]

atari4x4 wrote:

sure it's not just a batch of poor quality fuel... you still buying the cheap no brand fuel?

Hmmm, that's a thought. Might try a different mob.

I would've thought if it was fuel related then I would get a loss in power or worse fuel economy???

[atari4x4]

as OCD as it sounds.... when filling up around town i will always use the same pump at the same servo pretty much at the same time every couple of weeks.

[christover1]

atari4x4 wrote:

as OCD as it sounds.... when filling up around town i will always use the same pump at the same servo pretty much at the same time every couple of weeks.

I feel less alone now

[atari4x4]

christover1 wrote:

atari4x4 wrote:

as OCD as it sounds.... when filling up around town i will always use the same pump at the same servo pretty much at the same time every couple of weeks.

I feel less alone now

it's nice to know there are others out there.... over the last 3,524 kms my Vitara cost $0.20 per km to run on 98 Ron

[atari4x4]

TheOtherLeft wrote:

Here's a video I took. Note the engine is warm.

J20A video

I've now noticed it happens from about 2000RPM - 2300RPM. It's louder when the engine hasn't been run for a while (30min maybe but not necessarily cold) and reduces when it's been warmed up.

i've finally been able to watch that vid with sound, that almost sounds like a cracked manifold rather than PINGING (Pre-Ignition) or have you recently installed a new box of monkeys & hammers in you motor?

[steak_knife]

Take your belt off & see if it's still there, if it's not, wobble the water pump pully.
I've seen a water pump on a J20 wear through the housing before, still running & bugger all noise...

[Built4thrashing]

Was that the first time you have done an oil flush with a oil change? Sometimes these oil flushes can dislodge carbon sludge that can restrice the oil pickup causing top end rattle from loss of oil pressure.

Just a thought

[TheOtherLeft]

atari4x4 wrote:

TheOtherLeft wrote:

Here's a video I took. Note the engine is warm.

J20A video

I've now noticed it happens from about 2000RPM - 2300RPM. It's louder when the engine hasn't been run for a while (30min maybe but not necessarily cold) and reduces when it's been warmed up.

i've finally been able to watch that vid with sound, that almost sounds like a cracked manifold rather than PINGING (Pre-Ignition) or have you recently installed a new box of monkeys & hammers in you motor?

If it's a cracked manifold and assuming for example it's the exhaust wouldn't I be able to smell the exhaust from the engine bay?

[TheOtherLeft]

steak_knife wrote:

Take your belt off & see if it's still there, if it's not, wobble the water pump pully.
I've seen a water pump on a J20 wear through the housing before, still running & bugger all noise...

Would a faulty waterpump show other signs, eg increased water/engine temps?

Also, wouldn't the rattle come from the waterpump area-ie near the thermostat? The rattle seems to come from inside the engine block itself.

[steak_knife]

TheOtherLeft wrote:

Would a faulty waterpump show other signs, eg increased water/engine temps?

Also, wouldn't the rattle come from the waterpump area-ie near the thermostat? The rattle seems to come from inside the engine block itself.

Not all way's

goes right through the block, I had an apprentice once tell me it was a loose flying wheel...

10min to check.....

[TheOtherLeft]

steak_knife wrote:

TheOtherLeft wrote:

Would a faulty waterpump show other signs, eg increased water/engine temps?

Also, wouldn't the rattle come from the waterpump area-ie near the thermostat? The rattle seems to come from inside the engine block itself.

Not all way's

goes right through the block, I had an apprentice once tell me it was a loose flying wheel...

10min to check.....

So are you saying, remove the belt, start the engine and listen? Wouldn't running the engine without the belt be really bad???

I don't have my tools with me, but I went out and gave the waterpump pulley a big shake with the belt still on. No movement...not that I was expecting much.

[TheOtherLeft]

Maybe it's a pulley bearing??? I found this Youtube clip that sounds very similar:
Random youtube clip

Is the easiest way to check for bearing play removing the serpentine belt then pulling on each pulley or spinning it by hand and see which moves/squeals?

[fordem]

You can start and run the engine from cold for maybe 5~10 minutes without the belts without any worries - and in my experience - removing the belt and spinning the pulleys by hand is the best way to detect bad bearings on any of the belt drive accessories.

The pulleys will spin true, with no shake whatsoever, but you'll be able to feel the "rumble" of a dry bearing quite easily - if it is one of those pulleys, the bearings in the idler & tensioner pulleys can be pressed out & replaced.

[TheOtherLeft]

fordem wrote:

removing the belt and spinning the pulleys by hand is the best way to detect bad bearings on any of the belt drive accessories.

Yes that's my next course of action. Thanks.