Thread: Noisy Isuzu

They all are pretty noisy, but I'd check there is not a slight leak on the exhaust manifold gasket. Might be worth looking at the tappets as well, and consider the condition of the engine mounts and make sure you don't have any bits of the engine touching the chassis or body - its a pretty neat fit in a few places.

But I think the bottom line is that the Isuzu is a very noisy engine - it is a truck engine, not a light truck or car engine, and the design is several decades old.

John

I haven't ever come across a quiet isuzu. So saying, they do notoriously have tappet dramas. I for one, have been too lazy to adjust the tappets on my Rodeo work ute since I did a head on it. My laziness is just starting to annoy me!

I heard an Isuzu Stage 1 coming 1 km away not long ago - not under any load!

Your solution might be a louder stereo

Steve

They can be quietened somewhat by adjusting the timing, but my mind is too fuzzy at the moment to recall which way.

Originally Posted by scrambler

I heard an Isuzu Stage 1 coming 1 km away not long ago - not under any load!

Your solution might be a louder stereo

Steve

I seem to remember hearing a long time ago that the Stage 1 Isuzus had a slightly higher compression ratio than that on the 110 to reduce the noise, probably a different head gasket. One interesting difference is that the Stage 1 has two mufflers where the 110 has only one. A lot of my noise is exhaust noise, especially at speed.

John

Cheers guys
The engine has recently been rebuilt, so it's not bottom end, I've replaced the whole rocker assy with no differance, and I've had it next to another Isuzu rover and it is noticebly (spelling?) louder.
Did a compression test and their all 24 kg/f - m2 which is around half way for there limits.
Have adjusted the timing a couple times ranging from 12' to 7' to no avail.
Engine mount are brand new and nothing is touching the chassis, I'm thinking it's something internal, piston or gudgon pin maby.

Cheers Fellas

If it is noticeably noisier than a similar vehicle, and has recently been rebuilt, it does suggest a problem with the rebuild - something out of tolerance or not tightened, or even something like the wrong bearings for the journal size.
You say the engine has just been rebuilt - did this include pistons and sleeves? If it just had new rings there may be excessive piston clearance, for example.
Another possibility is inadequate oil pressure for some reason - have you checked the actual oil pressure?

John

It will also depend on the engine. Stage 1's had an earlier version of the 4bd1 that didn't have any noise deading parts fitted to it. And so it is normal for that engine to be significantly noisier that a later engine. I myself have heard the rattle of a Stage 1 Isuzu at least a k away. If you have an early model county maybe it has an early engine? One of the most noticeable things about the later engines is that have a cover over the rocker cover. Looks just like it has a pressed metal rocker cover but when you try and take it of there is a cast allor real rocker cover underneath. And there was some other changes to side covers and things. All this was to reduce the diesel rattle. I have also noticed that noise from the aircleaner can sound like exhaust noise. So it might be worth checking things out around there. I have been considering putting some insulation around the aircleaner myself and seeing if it makes a difference.
If you injectors aren't spraying properly they can make it rattle more.
Hope i haven't confused the issue.

WR