Mysterious noise

[ronhud]

I can hear what is best described as a 'warbly squeek' from underneath either the instrument panel or engine compartment cover. It is loudest when I first switch on the engine, seems to quiten down a bit when the engine has been running a while, does not occur when the engine is under load, can be heard sometimes in overrun and sometimes when parked. I've taken everthing out of the glove box in case it was just a rattle from there. Any ideas please - gearbox, engine mountings or what?
Ron

[mikeonb4c]

I can hear what is best described as a 'warbly squeek' from underneath either the instrument panel or engine compartment cover. It is loudest when I first switch on the engine, seems to quiten down a bit when the engine has been running a while, does not occur when the engine is under load, can be heard sometimes in overrun and sometimes when parked. I've taken everthing out of the glove box in case it was just a rattle from there. Any ideas please - gearbox, engine mountings or what?
Ron

Morning Ron. Are you quite sure its not squeaky belts? That one can be tested (but not cured!) by squirting WD40 on them I believe but have a search on here to read old threads giving advice.

No doubt others with more savvy will be along with other thoughts shortly

[321Away]

check around exhaust manifold, a snapped stud makes a sort of warble/mouse stuck under the seat noise? check that the forward most lower stud is intact or for black 'sooting' around manifold at front end.
Julian

[ronhud]

Thanks Mike and all for speedy replies - usual Bongo service. I wrote my question just after coming in, I've just been out and raised the passenger seat and cant hear the noise at all so I have to assume thats because the engine is warm. I'll leave it to cool and try again, could even drive with the passenger seat up and listen. I looked up the earlier threads, there is a good one with lots of info about belts and manifold studs - altho it's a bit like reading medical books, OMG what have I got!
Ron

[missfixit70]

Have you got a mason or low coolant alarm fitted? Could be one of those with an iffy connection or LCA could be on the verge of going off properly?

[Northern Bongolow]

check and remove the intercooler pipe mounting on the underside of the nearside chassis leg,
follow air pipe forward from the turbo,it dips down towards the aftercooler it has a rubber mounting that when examined closely is found to be rubbed through to metal insert,its sounds like an engine mounting gone its that noisey especially on startup,and switching off,
hope this may help.

[ronhud]

I am getting confused with this noise!

Engine cold, passenger seat up, started engine (gear in P) - cant hear sound.
Change to reverse - sound appears - change to D - sound gone.
Drive off in D, need to slow down and brake at junction - sound appears.
Check ATF fluid following instructions re ranging through the gears and end in P. No smell, fluid looks bright and golden and reaches the top of the letter F on dipstick.

Definitely not the LCA or Mason alarm.

Looks like I need to follow ADY's suggestion. I've looked at the lushprojects diagram, ADY is the part you refer to labelled 13-363N on the diagram? It looks as if I need to get underneath and remove the pan under the engine to check, is that right? Is there an overview diagram anywhere that shows all the main bits around the engine - bit like the drawings of the human body simplified to show where all the organs are!

I'm going away now untill tomorrow night so hopefully I can nail it down when I get back
Thanks to all
Ron

[mikeonb4c]

I am getting confused with this noise!

Engine cold, passenger seat up, started engine (gear in P) - cant hear sound.
Change to reverse - sound appears - change to D - sound gone.
Drive off in D, need to slow down and brake at junction - sound appears.
Check ATF fluid following instructions re ranging through the gears and end in P. No smell, fluid looks bright and golden and reaches the top of the letter F on dipstick.

Definitely not the LCA or Mason alarm.

Looks like I need to follow ADY's suggestion. I've looked at the lushprojects diagram, ADY is the part you refer to labelled 13-363N on the diagram? It looks as if I need to get underneath and remove the pan under the engine to check, is that right? Is there an overview diagram anywhere that shows all the main bits around the engine - bit like the drawings of the human body simplified to show where all the organs are!

I'm going away now untill tomorrow night so hopefully I can nail it down when I get back
Thanks to all
Ron

It does sound like its linked to torque pushingthe engine over in one direction as opposed to the other (I would imagine R and engine braking would both push engine in one direction, whilst D and acceleration load would push it in the other. Just need to work on which causes what but it does sound like engine mountings are a possibility.

Ady - what led you straight to this thought (engine mountings)? Have you come across it on a Bongo before? Other vehicle? To me, it seems an unusual thing to go, but then I know nowt about owt. Are they easy to replace with the engine in place?

[francophile1947]

fluid looks bright and golden

Shouldn't it be red? - all the Dexron 3 I've seen has been

[Northern Bongolow]

the intercooler system is mainly the hard plastic black ones,follow the system around the engine both sides,there are at least 4 places where it bolts to the chassis,remove undertray and they are easy to get at.remove these mountings starting with the one on the nearside front,the rocking of the engine chews through the side of the rubbers and goes metal to metal,
even if they look ok remove and check them carefully.

[Northern Bongolow]

mike mine went on mine it drove me mental trying to locate what it was.
it was a bit like that old tv advert where that bloke oils his wifes earings,before you say it yes you are old enough.
i thought at first it was an engine mounting fault.

[missfixit70]

Thismay help if it's the intercooler pipework - http://www.lushprojects.com/bongopartsm ... mgno=.html

[Northern Bongolow]

thanks kirsty,
i wish i could do that,
2 nearside mounts have a metal sleeve,thats the prob when it eats through the rubbers.

[ronhud]

Update: The alternator failed, recon fitted and mysterious noise gone so it must have been the belts as suggested originally. I now know the sound of a slipping belt.
Ron

[mikeonb4c]

Update: The alternator failed, recon fitted and mysterious noise gone so it must have been the belts as suggested originally. I now know the sound of a slipping belt.
Ron

Interesting. It seems to me that increased resistance to turning (as might happen if a water pump or alternator bearing was failing and/or when a heavy load is put across an alternator causing it to generate a large back-EMF) might provoke belt slipping if the belt tensioning is on the slack side. I wonder if that could be what happened here. I get what sounds like a bit of a sqeak on mine sometimes when engine is cold (has done it for 3.5 years) and I've never really known why.