What is the small hole on the front of suzuki grab vitara water pump

no engines stated, must be the H25/H27 V6
suzuki has 53 engines
and about 5-10 of those used on GV.
G16 , J20, or H25 series of V6s
toss coin, land on H engines.
on the V6s, the front cover needs to come off
exposing the cam drive chains.
its a horror this engine.
here is show a link to the real FSM pages on this engine.
here are the steps just to get to the pump (water)
the real page in the official book here.
http://jeepdied.com/look/24hr/SQ416-engine%20cover%20off.jpg

It's easy to do - the most difficult part is going to be finding the correct wrench to fit the plugs - you need a 10mm square drive - I know it looks like it's a 3/8" square drive, but it's not, and if you use a 3/8" square ratchet drive, as many people do, you run the risk of rounding out the hole...

Park the car on level ground and set the hand brake (parking brake), slide under the rear end and remove the fill plug (the higher of the two plugs) first - if you do not get the fill plug out, do not remove the drain plug.

Once you have the fill plug out, place a drain pan under the axle and remove the drain plug (the lower plug) and allow the oil to drain - give it half an hour or so - and then replace the drain plug and add oil through the fill hole until it starts to dribble back out, and then replace the fill plug.

You need 2.5 litres (5.3 US pints) of 75W85 GL5 oil, and it helps if you get yourself one of those cheap "oil pumps" - this is just an example, I'm sure the auto parts place nearest you has something similar.

Oil pump is attached to bottom of engine, inside oil pan. It's about a 5 hour job with proper tools.

She's rusted in the floor pan/ wheel well area--contact body repair or sell/ junk it.

Gear Box Oil refers to manual transmission normally. Goes in a 1/2 inch or so hole in the side of the box. You don't need to add unless it is leaking. Remove the plug and put your finger into the hole. If you get oil on your finger, it is full.

I'm not familiar with a 'vautomatic' ... if this is a type of automatic in the Suzuki (I am a Suzuki MC expert) you will find the dip stick in the engine compartment. There will actually be two dip sticks ... one for engine oil (black) and one for the trans (oil should be red or pink). If it is dark or smells burnt, have it replaced.

If you have a 2.5 V-6, you need to pull off the front timing cover, to gain access to the waterpump. If you do the work, you need to move the intake manifold up, to move the valve covers up, so you don't tear the valve cover gaskets. It is a 8 hour job by yourself. There are shortcuts, but it is not easy. Don Suzuki man

this engine produces timing chain noises at aprox. 50.000 miles (80000kms) depending oil service intervals

are you sure it's comming from the bolt, and not the pump housing, if so, remove the bolt, dry the bolt and the hole really well, and put RTV on it, should dry up your problems

Four or six cylinder engine and behind or front of the oil filter? Looked under my GV 2007 2.7 V6 and can not locate a shiny metal box next to the oil filter. Only thing that was shiny was the exhaust manifold and oil sump which are quite hard to break or puncture. If it was the oil sump you will have to remove it and get it welded as a bog will not hold on heated engine parts.

I don't have an answer for you but maybe a solution. Other than having a shop manual you could try the library. In most cities there is a service that is free at the library. It's called "Alldata" and it is the same system that shops pay to subscribe to. It will tell you in detail how to get the pump out and back in.