Volkswagen Polo Engine Problems

You could well be on the right track here. Many cars with transmission coolers place them in the car's radiator so that the liquid that cools the engine, also cools the transmission. But if the transmission cooler fails, that can allow transmission fluid into the car's coolant system which might account for the oil you're seeing in your coolant bottle. Many mis-diagnose this as a blown head gasket because the outward symptoms are very similar.

If this is the case, the bad news is that coolant has probably also entered the transmission potentially wrecking the mechanical parts and frying the electronic bits.

Firstly, check that it's the coolant overflow bottle you're referring to and not the windscreen washer bottle; it sounds basic, but they can look similar from above.

If there is a milky looking fluid and it is in the radiator overflow bottle, then you potentially have a head gasket problem on your hands. The first thing to do is take the car to a workshop which can confirm or rule out the gasket drama, and take it from there. Most workshops will probably conduct what's called a TK test which checks the radiator's coolant for traces of the chemicals that are created during the engine's combustion process. In a normal engine, these chemicals can't reach the coolant, but if the head gasket has failed, the combustion and cooling systems can intermingle. When this happens, a murky, milky coolant is often the result.

The recent cold, wet weather across much of Australia has meant that many car owners are suddenly finding milky deposits under their engines' oil filler caps, too. This is also a classic symptom of a blown head gasket, but it can also be simple a build up of condensation in the engine thanks to the prevailing weather conditions. This is especially true if the vehicle is used only for short trips. A decent run at highway speeds will often be enough to get the engine hot enough to evaporate these harmless deposits.

But don't assume that this is the case, as a car that really does have a failed head gasket can easily overheat in such conditions and that can lead to complete engine failure. Have the car checked by a professional and you'll know how to proceed.

If you've had to top-up the coolant twice in four weeks I'd suggest that your problems haven't been fixed and that you should take the car back to whoever supposedly repaired it and have them do the job properly. As for a "safe" option I can't really recommend one, except to say that I would avoid the DSG gearbox. The only "safe" option is to buy another brand, and in that case I would suggest a Japanese brand, such as Mazda, Toyota, Mitsubishi, all of which have a good record of reliability.

Despite your extensive efforts to fix this problem, it appears you still have a situation where the coolant and oil are mixing. No oil should be able to mix with the coolant (or vice-versa) and if it is (which is why you’re seeing oil in the coolant tank) then you have a fairly major problem somewhere in the engine. Check the dipstick. Is the oil in the sump milky and opaque? I’m guessing it probably is, and that’s another giveaway that your engine has a major problem.

Perhaps the cylinder head itself is cracked. Maybe the engine has a split bore. Perhaps the light skimming the head received was not enough and it’s still warped. Either way, the oil and coolant are mixing and that’s bad. The fact that the oil and coolant in the bottle are being forced out of that tank suggests combustion pressure is also playing a part, once again signalling a leak between the oil, coolant and combustion areas of the engine.

The lack of performance you’re feeling is when the car goes into ‘limp’ mode because it has detected a problem. Take it to your VW dealer and have them run a diagnostic check on it, which should identify the cause of the problem.

Oil leaks are a pretty common complaint in a second-hand car, but if the car as sold to you with a roadworthy certificate (which it almost certainly should have been) then there’s no excuse for those to reappear within two weeks of you taking ownership. I’m always suspicious of a second-hand car with a sparkling clean engine bay, as it usually means it’s been cleaned up to hide leaks, just as you’re now discovering.

Given that you bought the car from a VW dealership, I’d be having a chat with VW Australia’s customer service and complaints people as there might be something they can do to help in getting the situation sorted out to our satisfaction. On top of that, the dealer who sold you the car has an obligation under the terms of the second-hand car warranty. In WA, that means any second-hand car less than 12 years old (which a 2010 model is) and with fewer than 150,000km travelled, has to carry a one-month warranty on faults like the ones you’ve described. Since these problems were spotted at the two-week mark and pointed out to the dealership at that point, you should be covered.

The bigger issue from your point of view, of course, is that you were told the car had never been crashed when, in fact, it appears that’s not the case. That would seem like a fairly straightforward case of misrepresentation to me, and I’d be having the car professionally inspected (try your local State motoring club) and getting in writing the fact that it’s been crashed and repaired. From there, I reckon you’d have a decent chance of getting your money back and returning the car.

None of these symptoms are what you want to find. Any car mixing its coolant with its engine oil has some kind of internal failure (often a head gasket failure) and a car that is consuming oil at a fast rate is also probably suffering some kind of internal damage or wear. Have a mechanic perform a few basic tests on the engine (compression, leak-down and head-gasket) and proceed from there. But if it's as bad as it sounds, you could be looking for a new engine (or a new car).

These engines were known for being quite complex and perhaps not as durable as they should have been in some cases. They're also quite expensive to rebuild and may cost more to fix than the entire car is worth. At that point, you have some tough decisions to make.

Mazda2, from a classy brand and great against its size and price rivals; Hyundai i20, great value and probably still with some of the factory warranty; Volkswagen Polo, not necessarily to buy but to provide a quality benchmark for the others.

Assuming you're looking at the coolant catch-bottle and not the windscreen-washer fluid bottle, this is probably a bad thing. Any time the car's engine coolant can mix with its oil or vice-versa, there's a chance that the cause is a failed head gasket or perhaps even something more serious like a split cylinder bore.

But don't just assume that any contamination in the coolant is engine oil. It could be something else from another source. Does the engine oil look milky on the dipstick? If it does, then that's almost certainly due to coolant being mixed with it, and that backs up the failed head gasket theory. The other thing I'd like to know is how fast the engine oil level is dropping. Some oil use is normal for a car's engine, so simply watching that level fall over a few thousand kilometres and presuming it's going into the coolant is a long shot to say the least. It sounds like you need to have the car's cooling system pressure tested and the engine compression tested. That's the best way to put and end to the guessing game.

By the way, is your car a South African-bult VW? From what I can gather only South Africa got a model called the Polo Vivo which featured a few country-specific features and details and was very well received by buyers in that part of the world.

The car is now out of the 3-year warranty, so if you can’t prove that it did fail within the warranty period you will have trouble mounting a case to be fully compensated. The offer VW has made is a standard one typically used by carmakers.