I'm replacing a hose in my engine bay. A local radiator shop gave me some excess hose, but its max external temp is listed at 90C. I asked the shop why the external sheathing temp was so lowly rated and he said it has some kind of coating that helps prevent cracking, so the rating refers to the coating's max temp. The guy did say the hoses crack pretty quickly w/o the coating, so I'd like some input. The outside sheathing is only gas and oil resistant, but I assume that's probably fine. I'm more concerned about the sheathing's max temp.

According to my searches, the maximum expected coolant temperature is about 212, so I'm guessing a free standing hose whose max temp rating is @ 195 is fine? I've always been curious, too, about what the max engine bay temp is under load.

 

What are you trying to do? Just curious

 

Replace a coolant hose. I noticed a small slit in it when cleaning my TB. I noticed a tiny amount of coolant coming out when the system was under pressure, so I went to a local radiator shop to get some hose since they usually have excess. It's on there now, but I thought I'd ask before I wasted time and money to replace it.

 

What did the radiator shop tell you?

honestly, the cooling system in most vehicles is going to be very similar...if they use that type of hose on most cars I don't see why it would be any different.