Coolant leak

alnrs1963 · Post by **alnrs1963** » 06 Feb 2019, 18:01

I recently acquired an 08 C30 T5 with a coolant loss problem. The previous owner had the car and was losing coolant but had never taken it to a shop to diagnose the issue, he suspected a head gasket issue. It does not have any of the traditional signs of a leaking head gasket but I was able to track the leak to the lower radiator hose connection (driver's side). I can let it idle for 30 mins and not lose any coolant but if I take it out on the road and come back in there's coolant traces around that area. I tightened the clamp and took it back out and had the same results. It seems as though the system is over pressuring and escaping through the path of least resistance. The car runs great, does not over heat yet still loses coolant. I have not performed a compression test or a coolant system leakdown test yet. So, defective expansion tank cap not venting off, blown hg, something else? Just doing a quick check before I dive in

Post by **RickHaleParker** » 06 Feb 2019, 18:22

Put some Trace Dye (Fluorescent Dye) in the coolant. Take it for a run. Use a UV light to trace the leak back to the source.

alnrs1963 · Post by **alnrs1963** » 06 Feb 2019, 18:51

Thanks for the reply.
I believe that I traced it to the rad port on the driver's side. It seems as though it is over pressuring and blowing out around the hose connection. I tightened it up and took it back out to find that it still happened. It will not leak while idling, I do notice a steady stream of coolant back into the expansion tank for whatever that's worth. It's a great little car and if I have to pull the head and replace the hg I guess I will but only after ascertaining that is the issue.