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Serious overheating issue after using Prestone radiator sealer (3 flush+clean done)mm

648 views 0 replies 1 participant last post by  Cr4zy_C4nucK 
#1 ·
Hello everyone, am desperate enough to post this thread in the nooby tube...I will repost it in the main section when i can. About a week ago took one of the most stupid decision of my life, used a sealer in my B5.5 in order to prevent any small radiator/cooling system leaks in the future. (advice seen in a video from a veteran mechanic that operate a youtube channel) Car is a 2004 Passat 1.8t just over 225 000 km so I was thinking it might be smart to use it to prevent leakage down the road...I had weird feeling before putting the sealer, should have listen my guts. Anyway I did 3 full flush with flusher+cleaner after and engine still overheat. Every flush brought out more residu from the sealer, third flush very little. First few days I was able to drive around with the fan at 4, full heat, this I believe helped retrieve heat from the system using the heater core, I think anyway. Was able to drive around like that and keep the engine temp in check at 90 d as long as I keep the rev below 2000rpm, which means 4th gear was the limit. Now I cannot drive (from operating temp 90 degrees) more than 7-10 min before the car overheat uncontrollably, it reach the point where I stop, park somewhere the temp is close to 120, signal go off, etc. the fan at 4 and heat at high does not cut it anymore...Day 1 of controllable overheating, the return line to expansion tank was squirting hot coolant with fairly good pressure every sec or so...Day 1 of uncontrollable overheating hot coolant squirting with low pressure every 2-3 sec...definitely less flow...or is it really supposed to squirt out, I was always thinking it was a regular low pressure return like a river/waterfall type not a full blown squirting like a pussy or a water gun...how is the hot coolant supposed to return to the tank, what rate and flow range????
Also saw on youtube after the fact unfortunaltly because it would have been a game changer...some guy, radiator sealer clogged his Subaru system causing overheating, partially clogging his hoses/radiator and even crystalizing in some part or gasket I forgot the name...

I replaced the coolant temp sensor a week or more before the sealer+did an oil change a month ago Castrol Edge 5w40?30 VW 502.00 in it, so its not that.
water pump does not leak, but could be clogged because of sealer same with thermo.
While doing all the flush I quickly check the thermostat, did not notice any debris or residue suggesting the sealer clogged it or maybe those residues are small enough the I did not see them...
Every refill I do the proper way removing the firewall hose until water/coolant leaks out, removing air in the process...I even remove cap from "evacuation line" past the thermo and remove thermostat itself to remove coolant from engine completely prior to refill...
Suspect number 1...Auxiliary fan (passenger side) does not engage when engine reach over 90 but engage when cold AC is on...but again is that fan really enough to retrieve that much heat coming of the overheated engine?
Suspect number 2...Thermostat defective or clogged...
Suspect number 3...Water pump defective or clogged...
Suspect number 4...relay, fuse or connection to the dash instrument defective???...
Suspect number 5...clogged radiator, but I doubt it because passages are fairly wide, thermo and water pump would clogged or failed first before the radiator would...
Other possible suspects are, but I hope not, clogged turbocharger or oil filter coolant passage?? :( , motor simply ruined because of sealer (Subaru guy on youtube suggested he would need to overhaul his entire engine....
I have great manual dexterity, a good tool set, beginner/intermediate auto mechanical knowledge and capability, like to do everything myself with tender loving care and some swearing, will not take go to the dealership/mechanic as a valid answer.
I am not a professional mechanic, but my capability is not to be underestimate either, your opinion is welcome on the suspect list, What do you think???
I do not want to waste time and effort so suggestion from advanced member are taken seriously.
 
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