Hey everyone,

So, I went to look at an s4 today, and I really like it except for one thing. The owner says that there is a small interior coolant leak. He says that there are bubbles in the coolant reservoir, although I was stupid and didn't check for myself. I didn't notice any white smoke out of the tail pipe, and it drove nicely. Apparently the owner drove it for approximately 10k miles with the leak no problem. Assuming this guy told the truth, is there anything that could look like a leak (bubbles in the coolant), but not really be a leak? If there is a leak, how many more miles can I expect to get from the engine before I have to rebuild? My dad thinks I should go ahead and get it, he thinks I should get quite a few miles out of the car. Any thoughts? I can get the car with aftermarket rims, and an aftermarket stereo system for $950, so it's a pretty good deal. I am going back on Monday to buy it (probably), so replies are greatly appreciated. Thanks.

-jpieps

 

If the owner is disclosing that there are bubbles in the coolant I would believe him. There is no such thing as a "...small interior coolant leak." Any "interior" coolant leak will require an engine rebuild or replacement. A rebuild will cost $1,500 on up depending on who does it and how many of the internal components can be reused.

 

unless you can rebuild it and have the funds to rebuild it stay away from that one.; its just gunna be a head, well unless its an s5. then you can easily part it out and make your money back

 

Is there any other problem that can look like a leak but not be a leak? And if everyone is sure that it is a leak, do you think that the car could last until next summer when I actually have the time to rebuild it? Thanks.

-jpieps

 

A leak is a leak man. You can't mistake a leak. It's tough saying how long it's gunna last if the seals are already going out.

 

Assume the worst case. That is, internal coolant seal failure. You will not get many miles on that engine before it is totally destroyed. In fact, if he drove it 10K miles in that condition it is likely toast already. And if that's the case, most internal components will likely need to be replaced meaning big bucks. My advice is to save your pennies and look elsewhere for a car with a healthy engine.

 

I appreciate all of the input offered so far, I just have a question. Why will the engine now be "toast'"? What about coolant leaks ruins the hardware? Thanks again for taking the time to answer my questions.

-jpieps

 

With coolant leaking inside the engine, corrosion will be a problem. Now, if the car is driven often and not left to sit, then there probably isn't any damage. But if it starts to sit for weeks on end, stuff will start rusting.

Probably the easiest way to diagnose an internal coolant leak is to remove the spark plugs then pressurize the cooling system for several days. Then slowly crank over the engine by hand and check to see if any coolant ended up inside.