Overheating

[DarthMarauder]

Well ever since I got a chip with Lidios tune seems like every so many days when I start my MM and drive for a bit I start to overheat. Now here is the weird thing if I turn the vent on high at 90 the temp drops right back to normal and then I turn the vent back off everything becomes normal again temp goes back to half way and everything runs perfectly fine and it wont overheat till a day or 2 later it will do the same thing. Just wondering if anyone else has had this and what it is. Wondering if maybe its something with the tune. Also wondering if maybe my thermastat maybe is just struggling to open when I get her started from the cold. Any ideas???

[Blackened300a]

Air in your system, crack open the plug on the metal tube in front of the alternator with the engine running and see if air bubbles or coolant comes out. If you have air bubbles, keep repeating opening the plug until you have nothing but coolant.

[DarthMarauder]

Could air just suddenly come into my cooling system though? I have owned the car since 50000 and have never opened anything having to do with the coolant. It has 72000 on it now so I've gone 22000 with no problems just suddenly started happening after I got the tune. I think I may just get a new thermastat and see what happens from there.

[whoskal]

I had the same problem....very simple....your coolant system needs burped.

[mercmatt]

me too. air in the system

[Smokie]

I believe your overheating is totally unrelated to the tune, look for air in system, bad thermostat. I don't know why you are overheating.

The tune may have advanced your timing and leaned your a/f mixture some, a very lean a/f ratio causes the engine to run hotter, however you would be pinging pretty bad if you were that lean.

[MarauderMark]

I had a coolant smell all the time till i pressure tested it and found something to need an 1/2 a turn.just a thought..

[Mike]

When "burping" the cooling system, does it need to be up to running temp??