RC Colorado 4JJ1 engine rattle - anyone else?

judgemental_unicorn
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RC Colorado 4JJ1 engine rattle - anyone else?

Unread post by judgemental_unicorn » April 2nd, 2015, 4:50 pm

Forgive me if there is already a thread on this but I'm trying to find out what might be wrong with my 09 RC 4JJ1 (3L VCDI) colorado.

I picked it up today, it's only done 76,000kms. It has a strange rattle from 1700-2800rpm under load and the same rattle at 2700 when free revving. I know diesels are supposed to rattle but this is pretty loud! The rattle disappears when under load above 2700rpm. Car drives perfect, no smoke, no power loss.... Just a loud rattle.

The dealer I got it from said it had a lash adjustment? the day before I picked it up.

Just wondering if anyone else has had this problem?

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STEELJOCKEY
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Re: RC Colorado 4JJ1 engine rattle - anyone else?

Unread post by STEELJOCKEY » April 3rd, 2015, 3:48 pm

Not sure about the 'lash adjustment', but back lash usually has something to do with the diffs, so maybe they were talking about making an adjustment there.

Diesel engines are normally quite rattley, just the nature of how diesel combustion works, especially noticeable when cold on startup. But note that unlike a petrol engine, they don't need to rev anywhere near as much to get power out of them. By 2800 you'll be starting to lose torque, but from 1500 up to 2800 you have all the go you need. In fact, with a couple of mods you can keep the revs under 2000, otherwise about 2200 is a good change up point.

I've noticed that at around 2200 the variable turbo changes boost pattern, and from here I tend to get a bit more rattle noise unless I put the engine under considerable load, very noticeable in winter at single digit temperatures or below freezing. Don't seem to notice it as much in summer.

Probably everything is ok, but if you can find someone else has a similar vehicle (rodeo 2007-2008 or dmax 2008-2011 are the same as well), see how their's compares.
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mydmax
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Re: RC Colorado 4JJ1 engine rattle - anyone else?

Unread post by mydmax » April 3rd, 2015, 5:03 pm

The 4JJ1 engine does make a harsh sound when the injection is at various points in the running speed.
The injectors just happen to open and close ie, inject, a number of times for each power stroke and so when more fuel is being injected there will be more injection noise as the fuel actually ignites.

The dealer is on drugs, as it has absolutely nothing to do with back lash of anything. A Pie In the Sky throwaway comment from a person who has no idea but makes money from car sales.

The noise may be more pronounced when cold, so make sure your engine running temp is working at around 82C, if a bit cold, the cylinders won't be as hot and will make more noise as the injected fuel takes longer to ignite and so the instant pressure rise when ignition occurs will be louder.

I have a 2011 4JJ1 and it does similar, I just haven't heard yours though.

judgemental_unicorn
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Re: RC Colorado 4JJ1 engine rattle - anyone else?

Unread post by judgemental_unicorn » April 3rd, 2015, 9:05 pm

I took it to my mechanic for an opinion and he thought it was a tappet? I Know diesels are a bit rattley but this is WAY louder!

My mates MY10 diesel sounds fine, a tiny diesel rattle but mine almost sounds like a smacking/slapping noise. I can liken it to driving a car without oil, that noise.... Mechanic said it should be fine (I've driven to Port Pirie from Adelaide and going back Sunday) but it's booked it for Tuesday morning. Will let you know how it goes :)

the_brad
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Re: RC Colorado 4JJ1 engine rattle - anyone else?

Unread post by the_brad » April 29th, 2015, 9:56 pm

the dealer was probably talking about valve lash adjustment (tappets, valve clearances) if done wrong it will cause a rattle, or if a adjuster has been left loose it may be adjusting its self.

the tappets are annoying and difficult to adjust on these engines because they are deep down in the head, needing a nicely bent feeler gauge, deep socket with a handle or vice grips on it to lock up and release on and a screw driver through the middle to adjust. the clearances for both inlet and exhaust are .15mm.

id be getting the tappets checked again, especially if the dealer has attempted it but done a poor job, or just lying to your face, check around the rocker cover area and check for signs it might have been apart.

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Re: RC Colorado 4JJ1 engine rattle - anyone else?

Unread post by chris_stoffa » April 29th, 2015, 10:26 pm

Q. Does it sound like a couple of marbles rattling around in a can ?

If it does, spray water or squirt a bit of WD40 on your fan belts while the rattle is there.

If it goes away your belts need replacing or retensioning
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Suber
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Re: RC Colorado 4JJ1 engine rattle - anyone else?

Unread post by Suber » June 4th, 2015, 4:56 pm

This might be your timing chain tensioner - had a problem with mine recently (DMAX).

Have a look here for more details - viewtopic.php?f=113&t=158075&p=1813836#p1813836

Collie Colorado
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Re: RC Colorado 4JJ1 engine rattle - anyone else?

Unread post by Collie Colorado » December 24th, 2018, 7:22 pm

Mine has a similar rattle at 2000rpm to about 2400rpm. It's only under load up hills and in 1st and 2nd. I got the valves done and it went away for about 2 weeks but has started to come back. Think the valves might have loosened or maybe the injectors?

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