Have some overheating issues the past couple months and thought maybe it was a clogged radiator or my thermostat, that's about 6 months old took a crap.
. Here's Everything that's been changed and the car still overheats when you start to get on it alittle. Car is also tuned for a 180 thermostat so temps were always in the 180-190 range

New LT1 Radiator
New Mishimoto upper and lower radiator hose
New Motorad 180 Tstat
New Ac Delco Temp sensor
New Ac Delco Fan Relays
New AC Delco Radiator cap
New Cooling Fans. Work high and low. Verified
Cleaned out AC condenser with strong air compressor
Fresh Dex Cool every summer
Original WP, has zero leaks. Zero noise
Car has been bled out perfectly with front end being raised, hoses massaged and both steam tubed cracked open to get rid of any air
in stop and go traffic my temps climb over 200 and will keep going up until I hit the freeway which will then cool the car down as im no longer in stop and go traffic. As I was bleeding the car some more I noticed some tiny gold bubbles floating around at the top of the radiator neck. So this is engine oil correct? :/ as the car does not have a PS cooler. car only has 69k and been babied. I noticed the overheating a few months ago and thought it was just cooling fan as the passenger side fan stopped working due to the nut backing off on that fan blade. So I just put new fans in thinking that was the issue and fix. Well here I am now. Stumped. No smoke from the exhaust. No misfires but im guessing that is due to the HG having just a small leak? Like I said I will see gold bubbles float up to the top of the radiator neck when the thermostat opens. Going to do the pressure test with the dye this week. Also I noticed that when you start the car with the cap off after a min or so coolant will just start flowing out dumping everywhere. Is that normal as I don't recall it ever doing that in the past.

Any insight would be appreciated
Thanks

 

Sounds like a head gasket. Has somebody used a cooling system stop leak solution on this engine? Use one of those chemical test systems to see if the bubbles test positive for carbon monoxide. I think its called "Block Check" but a similar link is below.

https://www.napaonline.com/en/p/BK_7...waAlZ8EALw_wcB

Rick

 

Hello there! My IROC's LG4 305 had very similar issues when a I bought it. It spent alot of the years before I bought it sitting around. No smoke, no symptoms, no air in the system.... so I tore it apart. Turns out, in my case, there was just whole ton of crud and corrosion on all coolant passages in the engine. I think it was abused by use of tap water... Doesn't sound the same, but I was also wondering if you happened to use some of the "flush+cleaner" before changing your fluid yearly?

 

nope I've never used any stop leak since I've owned the car and I've also never used any of that coolant flush stuff.. i will try that dye test this week.. ****.i was hoping it wasn't a HG

 

If you're not able to detect any indication of a bad head gasket, I reccomend draining the system and fill it with a bottle of the rad flush and top it off with distilled water. It should have instructions on the bottle for a "deep clean."

 

The stuff in my link above is not a dye though it does depend on a color change in the fluid if it detects carbon monoxide in those bubbles.

Rick

 

What fans are on it? The OE style or aftermarket universal or...?

If it only overheats at idle that's usually due to lack of air flow across the radiator while sitting, or low coolant speed due to funky thermostat or water pump.

 

I replaced my OEM fans with Dorman fans. I do hear the fans go on high but im wondering if maybe there arent spinning fast enough? The only reason I changed to these fans was because the bolt on the bigger fan backed out so only 1 fan was spinning while I was driving around. So I said F it and just installed new fans which didnt fix the issue. The car did not overheat at all while I was driving it with 1 fan spinning. I did find the bolt that backed out so I am going to put the OEM fans back in and hope its the aftermarket fans that are causing this issue. If not the only thing left is the replacing the 23yr old water pump and running the coolant test to see if exhaust gases are coming through which means "BHG" :/

 

I replaced my OEM fans with Dorman OE style fans. I do hear the fans go on high but im wondering if maybe there arent spinning fast enough? The only reason I changed to these fans was because the bolt on the bigger fan backed out so only 1 fan was spinning while I was driving around. So I said F it and just installed new fans which didnt fix the issue. The car did not overheat at all while I was driving it with 1 fan spinning. I did find the bolt that backed out so I am going to put the OEM fans back in and hope its the aftermarket fans that are causing this issue. If not the only thing left is the replacing the 23yr old water pump and running the coolant test to see if exhaust gases are coming through which means "BHG" :/

 

Pray the Dorman fans hold up, every electrical Dorman part I've put on has come back or didn't even make it out of the garage. I won't use anything from Dorman anymore.

 

and it was those damn Dorman fans. Swapped the factory fans back in the car and the temp no longer rises up like it use to. F you Dorman. This is why you stay away from anything dorman

 

Thanks for reporting back