Heating problem 90 4runner v6

I have weird problem with the heating in my truck, its a 90 v6 4x4... the engine get hot at a normal speed, but the heat takes forever to come out the fan, and it only appear to do so , only when im driving or pressing the accelerator pedal. if on a red light, the heat turn to cold air, if i press the gas pedal it turns bac to hot and tall mi lights and fan get brighter and turn faster.... and lets not even talk about the rear fan... seem like nothink but ice is coming out of it! i changed the thermostat recently, changed and veryfied the engine collant, flushed it and cleaned the system while i was ther and nothing changed! if you have any suggestion please help!

Reply to
mike_foh_runner
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I would first suspect you had an air pocket when filling and verify coolant level in radiator when cold. Try parking the truck when engine is operating temperature with the radiator higher than the rear of vehicle. Check coolant after cooldown to see if air pocket cleared itself. If good then I would suspect a possible restriction in heater core. Feel both heater hoses to see if they are hot. If one is hot and other is not then you are not getting flow through the core. Remove both hoses and apply a garden hose to the fitting that had the cold hose so as to reverse flush or backflush the core. Alternate to both fittings until you get a good flow and it's clear water. If you can't get this kind of flow then core will need to be pressure flushed or replaced. If this is good then I would suspect a problem with water pump. The water pump is a doubtful one as usually if it is bad you will get engine overheating as well as cabin heating problems. I have seen this problem though when the water pump vanes where eaten away due to cooling system neglect. HTH, davidj92

Reply to
davidj92

Thanx man!

I'll try everything tomorrow morning since i dont have access to the garage today. i thought of an air pocket because i had that exact problem on an older car i had before, but a friend of mine told me that the cooling system in a toyota is different and will take out the air pocket by itself... dont know about that..... but i'll try your tips and advice and let you know about it. but i think all the hoses are hot but not shure so ill check that out too....thanx and il llet you know as soon as im done! Mike

Reply to
mike_foh_runner

hi David!

I tryed all that you suggested starting by touching both hoses to see if they wher hot! and the bottom one was cold so like you said the rad most have been blocked. i used the garden hose and tryed putting it in the hose that goes from the thermostat to the radiator and the water wasnt comming out from the top hose (coming from the engine) and i immediately knew something wasnt normal and must be blocked. i tryed putting more pressure by sqeezing the garden hose and the coolant hose together but all the water was comming back. si i used tape, yes old ducktape and put some aroug my garden hose so it would fit very tight in the coolant hose (going to de thermostat) and then put back the spring clamp on the hose to sqeeze the garden hose, i put in pressure and water was comming out from the top hose but only a bit and then the garden hose would fly out the coolant hose and i ad to redo the same thing again and again. i even tryed putting my pressure washer nozzle in and put in some pressure that helped cause from that moment the water started coming out from the top hose more and more. so i played with it for 3 hours, putting the hose from the top then from the bottom and will i was there i clean the font rad again. but i was wondering why water wasnt coming out when i put the garden hose in the top coolant hose (because the thermostat must be closed) so i decided to put everything back together and poor some new coolant. i went for a spin and Man the air is comming so hot my pant caught on fire loll.. but seriously i wanna thank you for helping me out, sharing your knowledge ant time. i really appreciate it and have your self a happy new year! thanx again.

Reply to
mike_foh_runner

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