1991 Holden Barina Pricing and Specs

From what I can gather, the engine in your Barina is an interference design. That is, if the timing belt breaks, the pistons and valves (in the cylinder head) will, indeed, meet head on at speed, turning the engine to junk in a slip-second. So make sure the timing belt is changed every 100,000km to reduce the risk of this happening.

Some engines with timing belts are non-interference designs, meaning that a broken belt will simply allow the pistons and crankshaft to continue to rotate without hitting (or damaging) the valves. Replacing the belt and retiming the engine will return it to full health. You'll still be stranded by the roadside if it happens, of course.

By 'rides' I’ll assume you mean 'slips', which then slowly allows the car to build up to speed (as in, the rest of the car catches up with the engine). There are two major causes of this, the first is a clutch that is out of adjustment, and the second is a clutch that really needs replacement.

The problem you have, though, is that even if the clutch on the Barina is adjustable (and some clutches aren’t) the fact that you’ve been driving it with the clutch slipping suggests that you’ve already damaged the clutch to the point where it would need to be replaced anyway. Continuing to drive it can also put 'hot-spots' on the car’s flywheel (to which the clutch attaches) and that can mean the flywheel also needs to be resurfaced when you replace the clutch.

I reckon, at the minimum, you’re looking at a new clutch kit. Ignoring it will eventually wind up with the clutch expiring completely and you walking home.

A build up of carbon deposits (a by-product of burning petrol) is, indeed, a known fault with this engine. If it occurs, it can create the precise symptom you’re seeing (the check-engine light) but can also lead to an erratic idle and misfiring. There have also been cases where this engine has developed wear in the exhaust valve and valve-seat region, with similar end results. Unfortunately, the only fix is to remove the cylinder head and replace both the exhaust valves and their seats.

I agree that 52,000km is a depressingly low mileage for problems like these to occur, so you need to make absolutely sure it really is the cause before you start to tear into the engine. A leak-down and compression test may throw some light on things, as can an electronic scan of the car. A fault-code of P0300 is a big clue that the exhaust valves are at the centre of the problem. This model Barina was another Holden that was simply a re-badged South Korean-built Daewoo with all that implies.