Hi, been for a spirited drive this morning and noticed a horrible noise on lift off. been driving the car all this week but this morning the radio wasn't on, hence noticed the noise. the only way to describe it, is a groaning noise. tried it at different speeds and seems to do it in 3rd, 4th and 5th when backing off from say 50mph+

cars a my93 wrx. hard to tell exactly where noise is coming from as induction kit chatter from fmic and d/v don't help with noise levels when backing off.

could this be the gearbox or rear diff?

can select all gears as normal and gearbox oil level is as u would expect. new exedy clutch fitted 3 months ago and oils changed then.

any ideas would be gratefully recieved.

cheers
rob

 

might sound funny but does it sound like a cow going "mooooo"

if it is then its your dump valve.

stew

 

have you had this then? i wouldn't say it's a "mooooo" but i'm happy to try anything, it's only a bailey d/v so could be.

will take it off and plug hole and go for a run...

 

no dont plug the hole up!

if you have the old standard dump valve id say try that on it.

i havnt had that happen to me but other members on here have described it and its been the dv worn out.

i do own a 93 wrx tho

stew

 

[quote=axgt_bwaii]no dont plug the hole up!

Why not plug the whole up? Ok as a none permanent thing isn't it? That's the impression I've got from other threads on here anyway. Or is it cause of the type of turbo or something?

 

BTW, I have a noise on mine too. Not like a cow though. I kinda wish it was if that could be the BOV though. I'm pretty certain mine is the gearbox. It's ok if I am floating or accelerating, but if I let off the throttle all together, I get a grumbling noise. Cheap to fix anyone know?? I'm worried bout BIG bills for it if it goes on me altogether. I think maybe the main shaft bearings in the box? And again....

Chad.

 

[quote=Chad!]when the turbo boosts and you let off the throttle the boosted air bounces back off the closed throttle body. instead of exiting your dumpvalve (if you have blocked it off) it will hit the turbo blades. its only air you may think but when its got pressure behind it its dangerous. it will damage the turbo.

if you do suspect the dv then fit your old one or borrow one from a friend. make sure its a twin piston one other wise you will get a **** idle.

 

could be a worn clutch baring? does it rumble in neutral and then go quiet when the clutch is depressed?

 

I've started getting a similar noise on my wagon. It's very hard to decribe the noise, but I'd say a "slight grumble" is about right.

I drive the car all the time, so can distinguish the noise and I know it's there!!!

I'm thinking rear diff!!

 

been out again today, removed d/v and plugged hole on fmic pipe. this made no difference to the noise. rather than a groaning noise, i would now describe it as a jangling noise. would an exhaust make this sort of noise on lift off?

any more ideas?

is there a way to check diff or gearbox?

 

JDM WRX WHERE ARE YOU BASED MATE?
IF ITS LIKE A JINGLY SOUND CHECK HEATSHIELDS SOUNDS LIKE THAT FROM CERTAIN BITS BUT THEN ALSO THEN IT SOUNDS LIKE POSS REAR DIFF OR CENTER DIFF END CASE BEARINGS.

SO I WOULD FIRSTLY PUT THE CAR UP ON AXLE STANDS AND DRIVE IT UP EITHER WITH A STETHASCOPE OR A SCREW DRIVER I WOULD LISTEN TO ALL THE HUBS FRONT AND REAR. CHECK FOR PLAY TOP TO BOTTOM ON ALL WHEELS.
RUN THE CAR UP AT 50 AND LISTEN TO DIFFS ETC AND PUT STETHASCOPE ON END CASE OF THE GBOX THATS A COMMON ONE.


REGARDS

 

Heatshields.

 

hi, i'm based near cambridge. what heat shields are there. i don't have any round downpipe as i have full decat and also have s/s headers so none there either.

have access to both 2 and 4 post ramps at work, so will put on 2 poster and try listening to diff etc.

thanks for the help.

will keep this post informed as a few people have pm me regarding similar problems.

cheers
rob

 

If it makes a howl / whine noise once you lift off, and comes from rear of car, could be worn diff, the teeth whine against one another when not under power.

A grumble sounds like something is broken and grinding in the 'box or diff?

 

A grumble sounds like something is broken and grinding in the 'box or diff?[/quote]

would i not notice difficultly engaging gears or something if box or diff was broken?

 

I wish it did. I've had those kind of problems before, being the thrust bearing. This only makes the noise when you back off the gas when driving and the load is on the gearbox slowing you down. As soon as you put any throttle on, the grumble kinda noise stops. That's what makes me think maybe the gearbox main shaft bearing. But any advice that would not cost me as much will be highly appreciated.

Chad.