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Trobule shooting the cooling system


MACKS

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1996 e-7 350 mechanical, runs perfect, problem started as no heat just starting blowing cold air,temp was a little below normal, if I race the engine to 1400- 1600 the heat comes back,thinking thermostat I changed it and now its worse, I had the truck running at high idle for 20-30 minutes no heat,temp gauge wont budge, no water circulating at all,don't think its a head gasket no water in the oil and no oil or fuel residue in the water,is it possible something happened to the water pump internally, anybody ever have something happen the there water pump that could cause these issues like maybe the impeller broke or something?

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Water pump cavitation? Don't know if it's a problem with trucks, but cars its common after cooling system work for air to enter the system and get trapped at the impeller of the water pump.....most of the time a good "burp" will help get things moving again. Just a thought, some one with more heavy truck knowledge will chime in I'm sure.

Lack of planning on your part does not constitute an emergency on my part....

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Water pump cavitation? Don't know if it's a problem with trucks, but cars its common after cooling system work for air to enter the system and get trapped at the impeller of the water pump.....most of the time a good "burp" will help get things moving again. Just a thought, some one with more heavy truck knowledge will chime in I'm sure.

I think it was something like that,I drained it out again and re checked the thermostat, refilled and opened a few plugs' and got all the air out,went for a good ride and all is well,still hard to warm up at idle,the fan seems to be fully engaged when cold,that could be another problem.
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for the first ten to twenty minutes running every morning, my granite's fan runs until the needle starts to climb. Come on when it's hot, and that's all I ask for.

Lack of planning on your part does not constitute an emergency on my part....

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Still having a problem,some how air is getting into the cooling system, if I crack open a plug on the water manifold after the truck idles for a bit there is no water just air, once the air comes out than water but the air still keeps bubbling out,if not a head gasket where could it come from, air compressor, any one ever have this problem? Coolant is perfectly clean and no coolant in the oil..

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when you look in the radiator can you see it circulate? May still have some trapped air, on my B this past summer the radiator was burping and it was the water pump, it was circulating enough that I trouble shooted everything but, the last thing to do was replace it and found that was the problem all along.

Robert

"I reject your reality and substitute my own."

 

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by pass the air comp and see if you get bubbles. also valve off heater loop. It could be a cylinder liner with a

hole in the side of the liner or a cracked liner at the flange, is it pushing antifreeze out the overflow?

does the exhxost smell of coolant? white stains on exh. manifold or turbo ?

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when you look in the radiator can you see it circulate? May still have some trapped air, on my B this past summer the radiator was burping and it was the water pump, it was circulating enough that I trouble shooted everything but, the last thing to do was replace it and found that was the problem all along.

No water moving at all..

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by pass the air comp and see if you get bubbles. also valve off heater loop. It could be a cylinder liner with a

hole in the side of the liner or a cracked liner at the flange, is it pushing antifreeze out the overflow?

does the exhxost smell of coolant? white stains on exh. manifold or turbo ?

If it were a liner or a head gasket wouldn't I get at least a residue of oil or fuel in the coolant. the coolant is perfect as is the oil.no smoke or smell or whit stains,so the air compressor could cause this say if it blew a gasket or o ring or something.

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i am kinda haven the same issue with a mack truck i am working on it has no heat in cab blows cold air and needle doesnt move have replaced the thermostat and the temputare sensor and still notting. i believe it is a clk 490

Try what I said,crack a plug in the water manifold or the bleeder on top of the thermostat housing,My engine is getting air bound and it don't stop.

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well if you have no water movement when the eng is up to temp. (180-200)F remove water pump and inspect also if eng has a burp hose (small line from top of eng. to top resivor ) make sure it isn't plugged. the no water movement sounds like pump impeller failure . on my previous post ive had this happen and not lock up the eng. or contaiminate other fluids but this should be a last resort. and yes a compressor can cause this as well. blown gasket or bad casting . typicaly a unloaded comp will not push air into water so check as you watch the rad. for bubbles if comp is building air or is unloaded

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Ok thanks for come back,removing the thermostat now just to see if I get some water cmovement,if not water pump will be next,I cracked open the water lines from the compressor and no air bubbles at that point so do not think its air compressor, I'll get back later,thanks for help..

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Running with out the thermostat I see very little water movement and now the air bubbles are going to the radiator, drained it again and took the water pump off and took that apart, looks fine, guess there is only one thing left and that's the head gasket, time to bring it to a real mechanic.

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replace the water pump, just because it seems fine don't mean that it is, if it was caveating causing the air bubbles a $75 water pump is cheaper than tearing into the engine.

Why would it cavitate , the impeller looked like new, there is no play and it turns nice and smooth.I know the water should be gushing through with out the thermostat in but it's not. Thanks for your help.
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if the clearance between the impeller and the housing is to great it will cavitate check clearance and also check impeller fit to shaft ive seen them crack and be tight cold but spin on the shaft when hot. also check lower rad. hose. it may have separated internaly and wont allow any volume of water to get to the pump

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if the clearance between the impeller and the housing is to great it will cavitate check clearance and also check impeller fit to shaft ive seen them crack and be tight cold but spin on the shaft when hot. also check lower rad. hose. it may have separated internaly and wont allow any volume of water to get to the pump

Dam I already re installed the pump but not completely the fan is still off, thinking maybe refilling with coolant and run it for a short time with out the belts just to see if it still gets air in the system, if I don't see air bubbles at the water manifold or radiator then I will replace the water pump.

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New water pump did me no justice except to lighten my wallet a couple hundred bucks, tomorrow it goes to my friends shop so he can play with it,at this point I'm pretty sure the heads have to come off but he wants to check a few things first starting with the air compressor ,time will tell!

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Forgot to update,after checking a few things and doing a pressure test and I don't know what else,I gave him the ok to pull the heads,he said both gaskets were a mess,what ever that means, any way he replaced both and all is well,ran ten hours plowing snow and she ran like a top,I can feel the difference,so nice and smooth but not sure if that due to new head gaskets or the valve adjustment or both

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Glad you got it fixed.

Sorry the advice cost you some for the water pump, but if it was not circulating typically that would be the water pump, I am always leery about pulling a head off until everything else checks out, as you said there was no contamination, and it was not building pressure and blowing off.

Robert

"I reject your reality and substitute my own."

 

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