I'm not experienced with cars so referred to a checklist online while inspecting a used car and it all looked ok. As soon as we got it home the coolant tank was now empty after a 40 min drive (full upon inspection) and engine oil has been leaking underneath.

Called the mechanic and he told me to be wary in the future if a used car is too clean under the hood. He said they must've filled the coolant right before the inspection and cleaned up all the evidence of any oil leaks.

At first he thought it was just the clamps on the hoses from the coolant being loose and tightened those. He pressurized the tank and said if it was the water pump it would overflow but he put it up to double what it should hold and no overflow.

But after running it for a while he noticed the coolant was again draining but not leaking underneath so said it must be an internal leak. He looked at the timing belt and it was covered in oil which he says is from a lower crank oil seal and flicking up.

He also said the pipe that comes off the turbo seems to be leaking oil near the front. And said he saw another leak when he was looking at the turbo itself.

I'm just wondering if it is in fact the water pump leaking if it's not external and could hold the pressurized coolant tank. If not what else it could be, and what else I could do diagnostically to explore the issue. Would the leaking coolant and oil leaking be related? Or was it just a backyard mechanic taking it apart to check for the coolant leak not putting it back together properly and causing oil leaks in the pipes.

Any advice or information would be appreciated. I'm happy to go check out other things on the car at your request when I get home from work. Thanks

 

Here's my thoughts - you need to consider whether you havetwo separate things here or if they are related. 1) oil under the timing belt cover can come from three different things a) cam seals b) front main seals c) VVT hub/solenoid. cam seals can get pushed out when there's an issue with the PCV system/oil separator so first thing is to test for positive crankcase pressure (check youtube for how to do the "rubber glove test"). Oil leaks around the turbo are commonly the turbo oil return line seal, which can spray oil all over the place. Its possible for the turbo's seals to wear out as well which may show other symptoms like smoke out the tail pipe 2) coolant consumption may be a leaky hose, radiator, heater core, overflow reservoir or could be internal to the engine (head gasket, cracked head or block etc). As to what can cause both water and oil leaks, the main concern is when the two fluids mix, ie the milkshake on the oil filler cap or dipstick. This would suggest a head gasket or turbo seal issue, or possibly a radiator/oil cooler issue. If you are just concerned about external leaks, then I'd bet the the problems are not related (ie dripping coolant and oil externally).

PS - You should also check into local lemon laws and fraud. If you buy a used car from a dealer or even personal sale and they represent the car as not having any known issues (losing a quart of coolant in the drive home is not a recent event) then you will have a good legal basis for fraud and should simply return the car.

 

I'm leaning toward the oil leak being a separate issue that was caused by some backyard mechanics trying to solve or explore the coolant leak. Simply because there is a bolt missing on the charge air pipe which is supposed to secure it to the engine block. So that tells me it's a shoddy reassembly.

I suppose all the oil seals around the timing belt would need to be checked and obviously the belt needs to be replaced but would the oil damage the water pump? I don't think that's leaking because pressure was added to the coolant reservoir and no leaks came from the hoses or water pump.

The engine oil has no signs of milky deposit and the engine doesn't overheat when I leave it idling for 15 mins. The heater in the car doesn't work but there's no leaking into the passenger compartment. After 15 mins idling there are no patches on the ground at the front but the exhaust was dripping.

 

If the coolant was that low it needs to be filled, air purged, filled, purged etc until there is no air left in the system. That can also explain your no heat and even perhaps it's not leaking anymore, it could have been the loose hose.