Toyota Repair: Coolant leaking, cylinder head gasket, hieu tran

Question
Hi Ted,

I have a V6 1999 toyota camry 1MZFE engine w 143,000Km on it. I bought it w 126,000Km from a dealer 9 months ago. Interval service at 136,000Km w a very good report (including cooling system pressure test – OK), timing belt kit & water pump replaced at 140,000Km. Recently I found coolant is leaking out from the front left cylinder head gasket in morning start up then stops leaking after 30 secs or so, I suppose when the engine warms up and it starts leaking when the engine cools down. My mechanic checks the coolant in the overflow tank and engine oil taken out from the oil pan. They are all clear, no signs of water & oil mixture. The car is still running fine, no misfire, and no white smokes at tailpipe. He told me that there have been external leaks so far but internal leaks are coming up soon and the gaskets need to be replaced. My questions are could it be overheated before I owned the car and could the gaskets last 9 months before starting leaking? Should I replace the gaskets asap or keep adding up coolant (2 cups every two weeks) until there is a sign of internal leak? Gaskets replacement costs me about AUD $1,800.
Your advises would highly be appreciated.
Thank you very much

Hieu Tran


Answer
The mechanic is correct, this will eventually turn into headgasket failure internally which can cause severe engine damage,not to mention the inconveience of a headgasket failure while traveling.
Could it have been overheated before you bought it? Yes.
Could the leak take this long to manifest itself? Yes.
I know you didn't ask this question but just in case your'e wondering if the previous owner knew there was a problem, I would say yes and that's why they sold it.