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YellowJacket · 10-10-2009, 04:47 AM

I still dont understand that test, or even if its logical.

Have you checked the hoses on the reservoir cap like I mentioned earlier? Is the cap in good shape? The hose that comes OFF the filler neck should be connected to the cap and routed down the hose that goes into the reservoir in the coolant. the OTHER side of the cap hose that is the blow off hose should NOT be connected to that side of the cap. it vents the bottle. This is an easy mistake but a big one if they are switched incorrectly. Easy fix. TEST IT.

take the reservoir cap off with all hoses attached... use your finger to plug the hose that sits in the reservoir bottle in the coolant. blow air through each hose on the outside of the cap. you should NOT be able to blow through the hose that goes INTO the FILLER NECK with that reservoir hose plugged.... you should be able to blow through the other blow off hose while the hose that normally sits IN the reservoir bottle is plugged up. If this doesnt happen, switch the top two hoses.

Maybe your overheating got better when you plugged the engine bleedcock bleeder hose into the filler neck, because essentially you were stopping it up and if your reservoir cap hoses were connected improperly(reversed), you are sucking air into your cooling system instead of coolant. Just a theory....

Also.... just a story...

Mine just had a HG replaced. No white smoke, no oil in coolant, no coolant in oil... just overheated after long drives on highways at speed... could drive around city fine. Finally one day the water pump started leaking at the weep hole ... the overheating got worse.... then I couldnt even drive around the city for more than 30 minutes before temp spiked. Had to top off coolant after each drive to keep up with the loss of coolant. It was a BHG.

Not saying yours is, but just showing you that what you think are tell tale signs dont have to exist. The overheating could be other things. You have had some drastic measures to be still experiencing this.. a new HG? a NEW ENGINE?! Fire your mechanic.

You need to get your tstat back in there and all the hoses routed correctly.
When it overheats, is the front radiator hot? Are the front radiator hoses pressurized and hot? What are your symptoms when it does overheat? Boiling in the reservoir? Does it spew coolant?

10-10-2009, 04:47 AM	#13 (permalink)
YellowJacket 1985 16v NA 6-speed Join Date: Sep 2008 Location: Nashville, TN Posts: 415 Thanks: 8 Thanked 31 Times in 24 Posts iTrader Rating: (1/100% )	I still dont understand that test, or even if its logical. Have you checked the hoses on the reservoir cap like I mentioned earlier? Is the cap in good shape? The hose that comes OFF the filler neck should be connected to the cap and routed down the hose that goes into the reservoir in the coolant. the OTHER side of the cap hose that is the blow off hose should NOT be connected to that side of the cap. it vents the bottle. This is an easy mistake but a big one if they are switched incorrectly. Easy fix. TEST IT. take the reservoir cap off with all hoses attached... use your finger to plug the hose that sits in the reservoir bottle in the coolant. blow air through each hose on the outside of the cap. you should NOT be able to blow through the hose that goes INTO the FILLER NECK with that reservoir hose plugged.... you should be able to blow through the other blow off hose while the hose that normally sits IN the reservoir bottle is plugged up. If this doesnt happen, switch the top two hoses. Maybe your overheating got better when you plugged the engine bleedcock bleeder hose into the filler neck, because essentially you were stopping it up and if your reservoir cap hoses were connected improperly(reversed), you are sucking air into your cooling system instead of coolant. Just a theory.... Also.... just a story... Mine just had a HG replaced. No white smoke, no oil in coolant, no coolant in oil... just overheated after long drives on highways at speed... could drive around city fine. Finally one day the water pump started leaking at the weep hole ... the overheating got worse.... then I couldnt even drive around the city for more than 30 minutes before temp spiked. Had to top off coolant after each drive to keep up with the loss of coolant. It was a BHG. Not saying yours is, but just showing you that what you think are tell tale signs dont have to exist. The overheating could be other things. You have had some drastic measures to be still experiencing this.. a new HG? a NEW ENGINE?! Fire your mechanic. You need to get your tstat back in there and all the hoses routed correctly. When it overheats, is the front radiator hot? Are the front radiator hoses pressurized and hot? What are your symptoms when it does overheat? Boiling in the reservoir? Does it spew coolant? Last edited by YellowJacket; 10-10-2009 at 11:20 PM..