Sluggish performance on 2000 Kia Sportage

Vacuum leaks work like this. A small hose breaks, you don't notice a engine problem, but the gas mileage goes down a bit. As the leak progresses, mileage goes down more. A large leak you notice the engine runs rough at idle. Combine this with clogged air, fuel filters and clogged catalytic converters and it will start killing the engine at stops and eventually go down the road. But to answer your question, No the line going to the diff, wont affect the engine performance. Because the PCM will compensate for the small leak. More fuel.

Towing

Kia lists a maximum trailer towing mass (trailer plus load) of 1800 kg for the Sportage but that figure would be illegal in NSW. For light commercials (such as the Sportage) in NSW, the regulations state that the loaded trailer must not exceed 2/3s of the gross vehicle mass (GYM) of the towing vehicle. The Sportage's GVM is 1928 kg, resulting in an allowable maximum towing mass of 1292 kg. Even this figure could be beyond the Sportage's reasonable capabilities, given its sub standard handling and its overall levels of performance.

Kia Forum

I had a simular problem.
Ended up changing the themastat and the gears changed into overdrive when the temp. got to normal running.
Be carefull that you get right thermastat though. You want one that reaches the normal working Temp as soon as possable.
Hope this helps.

5 minutes is a long time to drive a car with no coolant. Does the engine run rough, or miss? Or is it just sluggish and low on power? If it got hot enough, there could be permanent damage to the engine. Overheating can cook the engine oil into a gummy sludge and loses it;s lubricating properties.Check for signs of coolant in the oil. That would indicate a head gasket failure or a cracked head.

Yes, unfortunately this engine IS an interferance engine. The only way to tell if anything is bent is to install a new belt and see how it runs or perform a compression test. Let me know if you need anything else.

The most common problem that causes what you are experiencing is a plugged exhaust system.Usually the catalytic converter.The check engine light light should be on and the codes will lead to an oxygen sensor out of range,causing the fuel to lean out.If this is the case then i would look at getting the converter replaced.You could also have a vacuum leak which may or may not put the check engine light on.Let me know how you make out.

yes they are similar. you would have to pull the tank out to fix this problem

If the pump is running but not putting out any fuel the strainer in the tank could be clogged causing it not to pick up fuel. Also check the fuel pressure regulator and make sure it is working correctly.

We had o put in two new ignition coils along wit new spark plugs and wires. This solved the problem.