About 1,000 miles ago, I removed my Coolant overflow to fix the battery hold down that i broke last year. I drained and cleaned her out was nasty in there. I replaced her. I toped her off with Dex-cool.Next day I Had the shop I'v used for last 10 years do Motor mounts, Pinion seal,Diff cover seal and flush the cooling system. I get her back, next I take the car to work 10miles from home low coolant lights on. I'm in a rush and shes not overheating still cool out side i drive the other 20miles to work with out breaking 210. I Check coolant levels on my lunch shes low, I toped her off after work and tried to bleed out any air. Take it back to shop. 2 days latter I get the car back. Replaced coolant level sensor and was told system was bleed out. Seems fine for next 2days of driving apx. 150miles. I let car set for about a month. then next time out low coolant lights on again. I top her off this repeats a hand full of times over the coarse of 2weeks or so.
This week I pulled coolant out of overflow since it was full toped system off then started to bleed system. I messed up and truned car of and got an OL Faithful effect. after cleaning up i started Again. Seems to be fine but didnt put alot of miles on her. Thursday I did ls6 intake Swap with coolant lines.I bleed system again I didn't see any air come out. 115miles since last bleeding system after doing ls6 intake swap. I'v had to push coolant (By blowing) from overflow. 3 times!! All the hoses feel and look in good order, I'v let it set inside with cardboard under her only a few drips which i think was the overflow, Over Flowing. Since I Couldn't duplicate the next night. I was just at shop they tested Cap and said it was fine. There guessing its over heating But gauge hasn't showed me that. only hit 210 today in city driving was apx 85ish and humid. After lettig cool down was low And both Fans are kicking on

Any one have any ideas?? This has just about wrecked my week of vacation time?? Cant get car into shop until next week Thursday.

Can someone tell me or point me to info how to bleed this system? Maybe I'm just dumb but i'v bleed it the same way i have all other trucks and Toys I'v Had in past!

PS: before pulling coolant overflow to fix and flushing of system. The Radiator was never low, and Overflow hand maintained proper levels! Water Pump & Cap was replaced about 3-4years ago or 20,000miles ago

 

How often are you adding?

You need to park it somewhere and let it idle till hot, until you see coolant leaking (hopefully). My sixer had a leak right at the top of the res (not the filler neck, but the top of the base where the line goes in). Leaked just enough to not be noticable. Couldve gotten damaged on your ride. But again, how often and how much coolant are you adding?

And... Dont use Dex-cool. Ive seen first hand the hell the stuff that crap causes (yes on well maintained coolant systems). I know there are defenders of DX and I dont want to start a thread war. So Ill leave it at that.

 

Simple to bleed the system.

-Start the engine with the radiator cap off.
-Stand there till the t-stat opens and coolant starts to flow.
-If the coolant level drops down......IMMEDIATELY top it off.....the second it drops down.
-Then stand there and wait again and top it off again if the level drops....

Thats it.

Sounds like you may have a blown head gasket.

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I haven't ADDED in Last 115miles(The overflow is filled allmost to the top of the neck). I'm just relocating it from overflow to Radiator. by placing clean rag over the top of the overflow neck and blowing, Pushing coolant back into radiator. 115miles ago was last time i ADD coolant to system I i filled overflow first then bleed system. which left me with to much coolant in overflow.

Thanks for bleed info.
I'm not really seeing any consumption of coolant, or so it seems to me, Yet! But would make for a great time to put my CNC'd heads on!

The OverFlow has TOO much coolant in it. About 1inch from the top of the fill neck, then I transfer via blowing, the coolant back to radiator. After that the Coolant level is lower but is about where I put it last time, I did the Transfer via blowing. I have done this 3 Times with in last 115miles of driving. Does that make sense?

 

I know the shop said your radiator cap was good.....but its NOT if coolant is going into the overflow reservoir and you are NOT overheating.

Get a new cap and see if your problems are over. I use the Stant cap with the pressure release lever...its like $3.00.

Could be as simple as that.

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