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Discussion topic: Blow Head Gaskets ; No heat at idle
Posted to Technical Discussion Forum on 11/22/2013 39 Replies

The customer vehicle that is causing me to initiate this topic is a 98 Altima 4cyl. ... The vehicle is NOT a Help Request from me as the boss has already decided to send the car home with the owner, with a good will free of charge... We are convinced it is a blown headgasket, though haven't and don't intend to run a block test to confirm. ______________ Original customer complaint was of no heat coming from the HVAC vents, we each confirmed at least no heat AT IDLE .... Seems to be fine most of the time at operating engine speeds. A coworker replaced water pump, and it seems he used pliers to pull the heater hoses, so one was leaking, I repaired that... And we discovered the system has a bleeder by the upper heater hose on the engine. My initial cause for concern about the blown head gasket arose when I saw.... well, nevermind that... The kicker for me, was upon the last fill with a fill funnel installed, after bleeding, the cooling system continued to bubble air into the funnel even 10+ minutes after thermostat opens, and yet, the level in the funnel was never moving down. There's only one thing I can think of which can be pumping air into the cooling system at this point. That's the combustion chambers. I BELIEVE this is the first instance I've seen of a obviously blown head gasket that was not exhibiting overheating... The fans do NOT "stay" on, they seem to operate as they should. I can't imagine any other reason that this situation wouldn't be causing overheating of the engine. Any previous experience or insight to share guys? ___________________

I'm done with the vehicle, we know the customer won't want to do an engine, or head gasket. On a side note, two things, first, When I cold cranked the engine with about 10psi applied to the cooling system with pressure tester, there seemed to be no issues with getting heat from the vents at any speed. Second, I did pull 3 of the plugs, forth was cross threaded so I didn't even attempt to remove. None of the three cylinders where clean, nor letting coolant in. This vehicle drove the boss and manager crazy for almost a week before they told me to do anything with it. As soon as I said head gasket to the boss, he said let it go, no charge. Appreciate your time guys ;-)

Mason Cobb
Technician/Shop Foreman
Angel's Taller Mechanico
Winston-Salem, North Carolina, USA

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