I have a friend who has a 2008 that's blowing water out the cap. Its at the dealership now. They say its not a head gasket. Any suggestions?

 

Just to confirm, are you referring to "Puking Coolant" out of the Degas bottle?

 

If not headgaskets then they need to look at the EGR and thermostats.

 

Or just make sure the bottle cap isn't finished.

 

My buddy got his truck back from the dealership. Everything checked out good. He says that the only time it pukes is when he has his tuner on. If he leaves it stock he has no problems. Any suggestions?

 

really...........???????

take the tuner off, or be a bigger man and do studs.

 

Well.... this might be too obvious but leave the tuner in stock, or get a different tuner or tune.

What kind of tuner is it? Has it ever been working without puking? If so, what changed? Could the dealership be wrong? Lots of trucks with tuners on this site and they are not puking,

 

I second the the opinion about the cap,...it is crap and after a year it needs to be replaced, it is only $6 and worth the try.