Over the last six months done a lot of work to my truck. zf5 swap, removed motor replaced waterpump /oil pan/ stage 1 injectors/ hpop superduty/ new ipr. My truck is running stronger then it ever has but is rolling coal pretty heavily and smells like coolant. It was losing coolant but is not anymore , now it just has a smell of coolant and is getting 10mpg towing which is way worse then it did before. The truck only has 170k on it not sure what to look at next. any help would be greatly appreciated.

It also has tony wildman tunes that are set up for injectors with an auto transmission never had it reprogrammed for the manual tranny.

 

smelling like coolant can really only come from the exhaust. or from a leak in the engine bay. depends on where you smell it. if it's out the exhaust coolant is being burned and you have an internal leak if not search high and low in the engine bay. or leave it running for a good while on a clean concrete surface with the heat on and wait forany drips. Not sure on these trucks but i have heard leak at oil cooler and leak at head gaskets makes the difference between oil in coolant and coolant in oil. Have you checked for either?

 

have let truck sit and pulled drain plug for oil no coolant. coolant does not have any oil. I can pressurize coolant system to 15lbs and it holds steady. i can smell coolant in the engine bay from time to time after i drive it but no signs of leakage.

 

Not sure of the connections from hoses to the heater cores but i know on some vehicles they are quick disconnect type fittings, and over time the orings in them begin to degrade and coolant drips from there right up against the firewall, i would suggest with the engien running shake all coolant hoses etc and check everywhere coolant runs. If you can smell it in the engine bay then it's there.