Delica Canada | Mitsubishi Van Club

So for some time now my truck has made a strange kind of medium to high pitched howley/squeal..... Now this only happens (well I can only hear it) during deceleration normally from medium to high RPMs at lower speeds.

Recently I have replaced my timing belt and balance belt. It has a newish water pump and new accessory belts.

I have been doing a bunch of reading about the crank pulley and how it has a sort of rubber bushing that is responsible for some dampening. I have inspected the pulley and it does not appear to be delaminated.

Is there any other effective way to diagnose/test this pulley or is there another source for this noise that I have over looked, before I go and drop $300 or what ever crazy price on a new one?

Thx!

Edit: it's a 4d56!!

I think what you're talking about is the balancing shafts, but I don't know that they'd howl. Usually you'd more notice they're not working correctly by your engine shaking more than normal.

Check your alternator and steering pump - they are driven by pulleys and belts too (I think).

What you are referring to are the harmonic balancers that are spun by the crank shaft.

I am asking about a is the accessory pully itself, apparently it is has a rubber bushing

Here is a quote from the uk forum

"The crankshaft pulley does tend to be referred to as the front pulley, the exact description is Crankshaft damper because its made up of two parts, an inner section and an outer section, they are joined by molten rubber injected into the gap which makes it work like a shock absorber for the crankshaft. this shock absorsion allows the crank, con rods, pistons and flywheel (if a manual) to be used slightly out of balance as it absorbs the harmonic tremors that exist in the crankshaft train. without it the crankshaft would prolly snap into several bits in not too many miles. "

between the outer casing (pulley) and the inner casing (crank insert) there is a rubber moulding connecting the two peices. After time/wear it will crack or delaminate from the inside out. Sometimes you can't see it visually from the outside. Once it does separate, it needs to be replaced right away.

I have a post somewhere with a side by side comparison of a new one and one that 'looks' new but has delaminated and is spinning.

If you suspect it's on its way out, replace it. $300 and change is nothing compared to adding another zero once it does engine damage.

If the pulley is good but you're still suspicious, pull the pulley off and check the keyway. There should be ZERO play. Not even 1mm. If there is play, it will cause vibration/noise at the crank pulley and eventually the key will wear down and the crank pulley will spin freely causing engine catastrophe. I have a post somewhere with the pictures as well to identify a worn/new key/keyway and how to replace it.

http://www.delica.ca/forum/crank-pulley ... -9661.html

CVI wrote:Hi... Check the crankshaft key way housing for wear and ovality. Lots of times, when the bolt comes loose, the pulley starts wobbling on the shaft wearing that shaft quite a bit. If the shaft has worn down, there's no way you can put a new pulley and bolt without repairing or rebuiliding that crankshaft keyway and housing first. The only remedy is to pull the crankshaft out and get it rebuild professionally or get a used crank.

Sorry...

Butch

Ok well I'm waiting to hear back from CVI about their stock and I will swap the pulley this weekend if they have it. I will also inspect the key way in the crank. Hopefully all is well.

These are great trucks but they sure demanding for time and money!! Too bad the parts dont come a little cheaper

them's the breaks

Well.... Just spent 45 minutes at CVI. (met Falco) and had Butch look at my truck. He assures me it's not the pulley. But of course the truck only makes the noise intermittently and would not do it there.

So I'm at a total loss, if it's not the timing belts or tensioners and it's not the accessory belts, and it's not the crank pulley (thank god because it's $390!!) what could it be?? The alternator? The water pump?

Edit: more info

How does anyone feel about it being the rear differential? I cannot actually tell where this noise is coming from, and to be fair it does sound like its coming from beneath me..

"Many things can go wrong inside a differential. Although the hints are often subtle, most impending failures give fair warning in the form of noise.

Several situations can create ring-and-pinion noise. If the gears have been quiet and begin to howl, they are probably worn or wearing. If the gears howl during deceleration only, it’s possible that the pinion-bearing preload has loosened. "

I have had a similar 'howl' or not quite 'squeal' under similar conditions since first picking up the truck. You'll even find me trying to get more info on similar sounds and descriptions from other threads but nothing has ever come of it. I tried to recreate it a few times at CVI too, even once taking Butch on a pointless 15 minute ride.. Couldn't get her to howl though! Its usually only a problem when tooling around a parking lot or school zone, where you are barely accelerating at 1800-2200 rpm, or maintaining speed, and always when people are at an earshot. :). Butch says its fine and drive till something breaks and not to worry so much! Not what I like to hear even though Im hardly a paranoid person, but there ya go.

I doubt it is the rear diff, it happens under the front of the vehicle and after changing fluids a couple times, there seems to be no better or worse conditions for it to happen.

Japanoid told me it was a dirty EGR valve, then 'fixed' that by forgetting to bolt it back on properly only for my GF to call me telling the the truck sounds like a helicopter and smoking like chimney.. Then back again they told me it was a leaky turbo because there was a minor oil drip every few days (that was from the rocker cover) Yeah right, it already cost me an hours labour and two trips for them to eff up an EGR valve. After talking with them some more it was clear they really didn't know what it was and was far too happy to take the truck for a week, so I walked.

If it was the turbo, why would it only happen at a 0-2 PSI when at a full 14 there is no noise just a healthy hiss of it doing its thing. Sometimes its when cold, sometimes right off the highway, seems mostly when its damp out, but happens also sometimes when its a nice day... I'll just rebuild the turbo at 200,000kms regardless and Im sure it will be fine. Three years later and it is no worse, in fact probably happens even less.

Yeah, I drive the Paj pretty hard and only maintain as needed and nothing has failed that wasn't a maintenance part like water pump, hoses, rocker cover seals etc. Even these things go slowly, so no big deal unless you're paying someone else to do the work. My only beef is that these warning leaks happen twice a year, and only when I have to use the truck the next weekend for a trip. I figure once caught up on replacing all of the little stuff it should be a solid truck. Time and money will tell. Was still cheaper than buying a 95 4runner with 300,000+kms with rust package. Then again, I know the 4runner never quits..

Guess I should have scrolled down a dat bit. I just posted about this too. First noticed it on the high way. seems to be most evident at 2800rpm and ONLY when accelerating. I think its the turbo but I am not sure. It sounds like its coming from in front of me right front wheel well area ish kinda sorta thing maybe
I need to take it to CVI soon and ask. I am confident I can make it happen when he is with me. Just needs to be warmed up well first.

Good luck, let us know how it goes.

Well I've got to be honest. I'm sort of glad I'm not the only one with this noise! Pajerry have you changed your alternator?

No sir. I did consider that though.

It hasn't made the noise at all lately now that Im listening for it... who knows..