Hey all,

Temperatures have started to plummet here in Central KY and I have started to notice a slight sweet odor from the rear of my truck (2017 Disco TD6 HSE, 123,000 miles) when first started in the morning, and when I leave to head home from work. Coolant levels seem to be ok (will check again tonight), no codes, etc. Is the sweet odor always coolant or does something cause a diesel to smell sweet with temperature change (DEF, engine temperature, etc.)? I have no CEL, water pump and coolant flush was completed in the last 6 months. Vehicle is driving great. What do I need to look for and where if there is a suspected leak?

Thanks in advance!

 

Anyone know if the coolant crossover pipes are a maintenance item on the TD6? Headed up to Chicago for the holidays and want make sure everything is in order before I find myself broken down on the side of the road. Seems like the reservoir/overflow tank needs some additional coolant, but will check again in the morning. Any insight would be much appreciated, thanks!

 

Sweet smell from the exhaust can be coolant in the combustion chambers. Blown head gasket. If you're low on coolant that might be a symptom.

 

Thanks @RyanLR3 , I think I have narrowed down that the smell is more noticeable at the drivers door. Does that change anything? Likely going to top it off in the AM and get it inspected this week, but any another thoughts/recommendations are appreciated!

 

If it's not overheating I'd just roll with it. Keep the coolant topped up until you can get it into a shop. Blown gasket experience in my past has come with a plume of sweet smelling and visible exhaust "steam" on cold start

 

Great to know. Appreciate you!

 

Topped off the system this morning, will monitor until I am able to get in. I have also noticed over the last couple of days that my heat and air is either hot or ice cold. Symptom of anything? Heater core possibly? Wondering if the system is gunked up.

 

If there's a bad head gasket the engine could be pumping combustion gasses into the cooling system, messing with coolant flow. It is possible to overpressurize the coolant system to component failure... Heater cores breaking, plastic coolant system component failure, hoses etc. Best to get it in the shop. Most any mechanic shop has the ability to test the coolant for hydrocarbons and if there are it's a solid indication of head gasket failure.

 

Thanks!!

 

While I agree it's a good idea to get it checked out at a shop, I think you should check out the simple stuff first. In cold weather, rubber hoses stiffen. If connections are slightly loose, the normal flex of a rubber hose will likely expand enough to prevent a leak. But as the rubber hardens due to cold, it looses that ability. First check any place a rubber cooling-related hose goes into or around a flange/metal connector.