Hey guys...

I did a quick search, but couldn't find an answer to this.

I've got this wierd rattle coming from the engine only when it's under load and it seems to be around 1200-1500 RPM. I remember reading somewhere that something to do with the exhaust can cause this. Does anyone know what this is? Any other suggestions?

Also, at idle when it's cold it sounds like a diesel for the first few minutes (sounds a bit like piston slap or something similar but it's only done 19,000 K's) and when it's warm it sounds "rattely". Although it's still smooth when it revs. It's done it since new :shock: :cry: :cry:

I'm, dropping it off at Colliins next week and leaving it there for a couple of days so I can show them how it sounds when it's cold. Has anyone else had these problems?

Any suggestions???

BTW it's a TJII if that helps.

Cheers.

maybe engine oil?? you didnt change it recently did you????
i changed my oils and i got the rattle noises under load....then i went to change it to another and it went....

kev

Hmmmmm....

Sounds F***ed to me. I reckon thats a whole new engine. Still under warranty I hope :badgrin: (jokes)

Seriously, like DajaJa said, perhaps its the wrong engine oil. Had exactly the same sort of noises from my first camry I bought but the engine was totally knackered in that thing. Hate to say it, but those noises should only come from mechanical issues like freeplay between parts where there should'nt be free play (or lack of lubrication). Perhaps your valve clearances simply need adjusting. Cant imagine one of the 6g74 engines going AWOL at only 19,000 k's. :confused:

I don't think it's the oil. It did it on factory fill, then after first service, then I changed to Mobil 1, then got 15K service and they use Mobil XHP or something like that...still the same :evil:

I don't think it the valves/lifters, 'cause it sounds like it's coming more from the bottom-end than up top.

Yes...it's still under warranty...but it might not matter anymore 'cause I just got made redundent this week (finish next week), so if I can't get another decent job within a few months I'll probably end up losing my house and car anyway :cry:

Yes...it's still under warranty...but it might not matter anymore 'cause I just got made redundent this week (finish next week), so if I can't get another decent job within a few months I'll probably end up losing my house and car anyway :cry:
Sympathies mate....hate to hear it :(

This was discussed somewhere else but i cant find the damn thread....I have the same problem...When i start the car in the morning when its cold, it makes a rattle sound similar to a diesel. and only at low revs when its cold..when the engines hot its virtually gone. Apparently its something knocking against the manifold.... if i coudl find the thread it would tell ya My car has 131ks

4G54 blocks - 2.6L 4cyl that are in the 2nd gens have almost the same noises when the timing chain and/or the tensioner is rooted. But in the new one? Who knows.

Hey thanks guys, much appreciated.

Yeah...I remember reading about the manifold or flex-pipe or something a while ago, but I couldn't find it. One of the guys in Spare Parts at Collins Mits. here in Melb. mentioned it to me as well so I'm taking it to them tomorrow to get them to fix it (well they better). I'm going to leave it overnight for a couple of days so they can hear the sound it makes when it's cold.

Yeah...thanks Mitsiman...piston slap is what it sounds like when it's cold, but I have no idea about the sound it makes at idle when it's warm??? It's definately not clutch rattle 'cause it's an auto (there goes my dreams of having a TT 300KW+ auto Magna!). It's been like this ever since it was brand new :shock: If it piston slap, legally what can I get them to do? New engine?

I'll wait and see what they say tomorrow, but it definately doesn't sound "smooth" (either hot or cold) like most other 3rd gens. I've heard :(

(C) Piston slap which some have come out with.


I have a soft tapping sound coming from my engine that is there all the time cold or hot, I've changed oils and no change in sound, could it be piston slap.

The car runs fine, smooth and is still very economical, but that dam sound????

Following your description, I am leaning more towards the lifters now, because the noise is audibly the same all the time and is always there, not loud but you can hear it with the bonnet closed (but not from inside the car).

I'll get it checked out soon :confused:

Hey guys...

I did a quick search, but couldn't find an answer to this.

I've got this wierd rattle coming from the engine only when it's under load and it seems to be around 1200-1500 RPM. I remember reading somewhere that something to do with the exhaust can cause this. Does anyone know what this is? Any other suggestions?

Also, at idle when it's cold it sounds like a diesel for the first few minutes (sounds a bit like piston slap or something similar but it's only done 19,000 K's) and when it's warm it sounds "rattely". Although it's still smooth when it revs. It's done it since new :shock: :cry: :cry:

I'm, dropping it off at Colliins next week and leaving it there for a couple of days so I can show them how it sounds when it's cold. Has anyone else had these problems?

Any suggestions???

BTW it's a TJII if that helps.

Cheers.


dude what ur refering to is what i posted and it was the exhaust where ur front manifold and therear join in a Y joint and inside that Y joint is a flap of metal that loosens itself and puts a hole on the exhaust the size of the top of ur pinkie the flap rattles around at a certain rev range but it only cost me $30 to fix mitsu wanted to charge $200+ for a new joint but my exhaust shop cut it open took out the flap and welded it all back up and i havent looked back from there a few boys on here have had the same prob.

hope it helps cheers brett.

Well I heard back from the dealer today. The rattle under load actually turned out to be the heat sheild that fits over the manifold had a crack in it!

They think the knock it makes both cold and hot is due to incorrectly sized pistons being fitted on the assembly line. When the engines are assembled, they have the standard bore and piston size, but the also have a few pistons sizes +/- a small amount to allow for different tolerances within the actual bore. And get this...they said that about half of the 6G74 is assembled by hand :cool:

Anyway they're going to pull the engine out of it and strip it down to check the piston sizes, and fit new ones and anything else it might need. Lucky it's under warranty. The down side is that I wont have my car for a couple of weeks :(

they said that about half of the 6G74 is assembled by hand :cool:

Well, that explains a bit...

but it only cost me $30 to fix mitsu wanted to charge $200+ for a new joint but my exhaust shop cut it open took out the flap and welded it all back up

Had exactly the same problem. I thought it was the CAT at first, and we spent ages with the stethoscope tracking it down, it only happend when it was cold so was a prick to find.

Funny thing is we did exactly the same thing to fix it :) ... bugger paying $200 bucks when extractors were going on anyway ....

Piston slap can be ascertained by slightly varying the rpm and it will float the noise.

I think i have piston slap in my TF, its done 162K ... when we play with shutting off individual injectors (using diagnostics), some of the cylinders namely 1, 3 and 4 rattle like a diesel :shock:

Given the likely hood of this, are there any recommendations on pistons (brands etc)? (Sorry if i have hijacked the thread)

Ok, what the heck does piston slap sound like?

Not being a mechanic and not having had exposure to all the different types of noises a busted engine makes I've got no idea if the noises my car makes are meant to be there or not... I guess that's what your mechanic is for but lately I've just been getting mitsu to do service my car and I wouldn't be surprised if some of their junior mechanics either didn't know what to listen for or just flat out don't care if things don't sound quite right. :(

I reckon that flap of metal in my exhaust has come loose again in mine.. I've already had them replace it once under warranty.. I haven't bothered getting it looked at this time though because I'm expecting Dave to call me and say the extractors are ready any day now.. *queue chirping crickets and tumble-weed* ;) ;)