CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Head Gasket - Possible Problem

Hello, Everyone:

I own a '99 Corolla with app. 121k miles. I brought my car to the dealer for a routine oil change. My “report card” indicated a red flag, i.e. there was oil seeping from the head gasket and from the oil pan gasket. The service advisor said that I should monitor it to see whether or not the seepage gets worse. He said that it didn’t necessarily have to be fixed now.

Everything I’ve researched on head gaskets indicates that if there’s a problem, a telltale sign would be leaking radiator fluid. I didn’t see anything about leaking oil. As far as the oil pan gasket is concerned, I figure that it’s a simple fix, and that I could do it myself, or save the aggravation and let the dealer handle it during my next service appointment.

So, here’s my question – should I be doing anything more than simply monitoring the situation? As a side note, I plan on selling the car in a few months, and I wanted to give the buyer all the service maintenance records. So, that red flag poses a bit of a problem.

There can be more than one type of head gasket seepage.

  1. There can be an external leak of coolant and/or motor oil. If the breached head gasket never moves beyond this stage, it is more of an annoyance than anything, due to the need to constantly monitor/replenish coolant and/or oil levels.

  2. There can be in internal leak, involving motor oil migrating into the cooling system. This is also not of immediate concern, and can be detected by looking for a heavy, dark line at the upper level of the coolant overflow reservoir.

  3. The most serious type of head gasket problem involves the passage of coolant into the motor oil. This type of leak can destroy the engine’s bearings very rapidly, and thus is…extremely serious. If you see that the oil on the dipstick looks like a chocolate milkshake, this indicates coolant in the motor oil, and it requires immediate action if you are to save the engine.

The potential glitch underlying the situation, is that the problem can start out as one of the more benign versions (#1 and/or #2), but can morph into the much more serious type (#3). Constant vigilance is necessary in order to make sure that version #3 has not begun.

All of this being said, it is possible that simply retorqueing the head bolts and the oil pan bolts might relieve the problem. Dealerships will rarely tell you of this possible cheap fix, so I would suggest taking your car to a highly competent independent mechanic (NOT to a chain operation like Pep Boys, Midas, Monro, Meineke, Sears, or…God forbid…AAMCO)

And, it should go without saying that you need to make potential buyers of this car aware of the head gasket problem. If you do not do this, bad karma will follow you for all your days.

Make sure the “head gasket” leak is not from the valve cover gasket which is attached to the head. Oil can seep from there and the fix is cheap. Oil can’t seep easily from the head to block gasket; only engine coolant (antifreeze) can

You need a second opinion from a good mechanic.