bajco1

Having studied and analysed the freeze plugs that were taken out by Cummins, there is NO WAY i can believe that the coolant caused the freeze plug to come out. The only conclusion i can come to is that one of the original plugs was not fitted correctly. Cummins would not agree with this as it makes them look bad and open up liability issues.

Thank you for your welcome and your helpful comments. When the Radiator cap failed it pushed out the coolant, the engine temperature rose and the engine sensor cut the engine. I put in coolant but do not know the brand or type only that it was suitable for Diesel engines. I have never come across plugs failing because of the coolant and neither have a number of mechanics I have spoken to. They have only seen erosion from salt roads around the plugs and not from the coolant. My coach has never seen a salted road. It is amazing to me that Cummins if they know this will erode and fail with the coolant do not put in a better material for these plugs. The plugs are about $20 and the fitting of a new set $3,600.

I have a 2011 Tiffin with a Cummins ISC 380 engine with 40,000 miles. I recently noticed a small amount of coolant on the ground when i stopped my RV. I checked the the engine and could not see where the leak was coming from. I decided to take it immediately to the Cummins dealer. On the way engine lights came on and I was forced to stop when the engine cut out. While stopped coolant just flowed out along the gutter. It was then towed to the Cummins dealer. They have inspected and told me that one freeze plug came out and another has a hole in it.They are now replacing all the Freeze plugs. I did have a problem with a faulty radiator cap some two years ago that i had to replace. the problem caused the loss of coolant that i had to replace. I have driving buses for 40 years but have never come across this problem, could it be faulty material that the freeze plugs have been made from? Has any other member had any experience or knowledge of other people with this engine having the same problem?