Serious engine noise

gavallday · Post by **gavallday** » Mon Sep 10, 2007 7:24 pm

Hi there,

I desperately need some advice. The cylinder head gasket failed on the Bongo recently. We were convinced that the engine had not been allowed to boil. Garage has replaced CHG but Bongo now has a very loud clanking noise and the suspicion is that a little end bearing may have failed, possibly due to nipping. The engine is not too noisy until you start to drive away, and any load results in the loud noise.

I have looked at other posts for clues and some describe similar noises when decelerating, not accelerating, particularly big end bearings.

I need to try and diagnose the cause of the issue without incurring costs at the garage. Can anyone advise whether this does indeed sound like a small end bearing. Is there anything I can do to prove this? I assume a compression test is a good start but what then?

If it is only the bearing, I might try replacing it and seeing how the engine runs rather that opting for the expensive engine replacement option.

For future reference, if anyone can point me at an article that would help with dropping the sump and removing the piston, I would really appreciate it.

Thanks for any help you can offer!
Gav.

Ralph · Post by **Ralph** » Mon Sep 10, 2007 8:29 pm

are you sure it's mechanical and not a sticking injector
due to being cooked. I once had a injector sick and
it sounded for all the world like a big end had failed

francophile1947 · Post by **francophile1947** » Mon Sep 10, 2007 8:51 pm

I would doubt that it's a little end - they aren't usually very noisy, unless they've been failing for a very long time. No simple test for them either - a compression test wouldn't show it up.

Ralph · Post by **Ralph** » Mon Sep 10, 2007 9:07 pm

they have got the valve timing right haven't they?
been inside hundreds of engines and can only remember
1 with the little end gone

gavallday · Post by **gavallday** » Mon Sep 10, 2007 9:11 pm

There was no sign of this noise before the CHG failed, so it s a bit sudden.

Willing to consider anything that isn't a replacement engine. I have no experience of sticking injector noises, but if you think they can be that loud I will investigate further. It does sound mechanical and metallic to be honest.

Thanks to you both.
Gav.

Ralph · Post by **Ralph** » Mon Sep 10, 2007 9:30 pm

if you can ear it with the engine ticking over you could
try loosening the fuel pipe union on each injector in turn
see if it disappears on one if so you could then swap the
injector with one of the others see if the noise moves
to that cylinder or stays were it is, but be very careful
very high pressures n things you only need to just back
it off a touch till it leaks, keep as far away as you can
your mileage may vary and all that.

gavallday · Post by **gavallday** » Mon Sep 10, 2007 9:44 pm

Thanks Ralph - sounds like good advice!

dandywarhol · Post by **dandywarhol** » Mon Sep 10, 2007 9:50 pm

Little ends tend to knock under light load - big ends knock under heavy load. If it's just happened since the gasket blew I'd be very surprised if it's a bearing failure.
Did the garage change the oil after changing the gasket? (they should have because it'll be contaminated with water) Is the oil level ok?

Ralph · Post by **Ralph** » Mon Sep 10, 2007 9:53 pm

Yes most things are powered by smoke and once the smoke
escapes they don't work, just be very careful at the pressure
diesel injectors run at diesel can cut skin safety first and all that

smartmonkey · Post by **smartmonkey** » Tue Sep 18, 2007 12:20 pm

It seems highly likely that the garage made a poor job of doing the cylinder head gasket. It sounded fine, went for repairs and came back sounding rough. They aint fixed it, shouldn't have returned it to making a noise and shouldn't charge for fixing it.

Captainsideways · Post by **Captainsideways** » Wed Sep 19, 2007 9:13 pm

Screwdrive or long stiff similar object, attach to ear, poke away at engine until you find the source. My bet is injector failing.

Be careful what you poke though keep away from moving parts!