MACKTRUCKS4

V-8 Running Hot

10 posts in this topic

Now my truck is starting to run hot. My V-8 Superliner is acting up. On long hard pulls, the temp. goes up to 220 with the oil temp reaching 230. When I level off, the water temp. comes down to 200, but the oil temp, takes a lot longer. I changed the clutch fan because I could not hear it lock up when it should. I still can't hear it lockup with the new one on. I do run dual open stacks so it is loud, maybe I just can't hear it. Does anyone know how to test the clutch fan? Maybe I have an oil cooler problem? The motor is fresh, pulls hard, pyremeter never goes past 1000. Turbo boost hits 27lbs. at max. The motor is turned up to around 650Hp. but never gave me problems of heating up. Lately it has bin using a little anti-freeze. No outside leaks, no signs of where it is going. Oil shows no sign of water in it. I think maybe I have a cracked head or a blown head gasket. I am going to do a exhaust gas check on the anti-freeze to find out for sure.

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Now my truck is starting to run hot. My V-8 Superliner is acting up. On long hard pulls, the temp. goes up to 220 with the oil temp reaching 230. When I level off, the water temp. comes down to 200, but the oil temp, takes a lot longer. I changed the clutch fan because I could not hear it lock up when it should. I still can't hear it lockup with the new one on. I do run dual open stacks so it is loud, maybe I just can't hear it. Does anyone know how to test the clutch fan? Maybe I have an oil cooler problem? The motor is fresh, pulls hard, pyremeter never goes past 1000. Turbo boost hits 27lbs. at max. The motor is turned up to around 650Hp. but never gave me problems of heating up. Lately it has bin using a little anti-freeze. No outside leaks, no signs of where it is going. Oil shows no sign of water in it. I think maybe I have a cracked head or a blown head gasket. I am going to do a exhaust gas check on the anti-freeze to find out for sure.

If you have the engine turned up as high as you say you should be making way more boost check for boost leaks! The boost should be more in the 32 to 34 range with a juiced engine.

also keep your air cleaner clean the engine will suck the elbow on the intake flat when pulling hard Once you got it running right!

as for the fan test cut card bord to fit the rad cut a 4 inch hole in front of the fan hub and warm up to temp.

Are the stats new? The over fuel combined with boost leaks can cause overheating!!! check that first as the engine is not putting out what it should!

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Air filter gauge is showing 10 on hard pulls, (I don't think that is high). Red line is 30 on the gauge. Stats are new. About three weeks ago, a clamp between the turbo and cooler broke, blowing the tube off. I did notice a small amount of oil in the tube. I wonder if there is enough oil in the cooler to block the tubes up? Causing lower boost. As for the fan test, do you put the cardboard between the rad. and the fan? and does that direct the hot air to the fan hub? do you rev the motor up?

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put the card board in front of the rad so that it does not damage the fan blades. rev the engine to around 1400 and listen for the change in fan noise.fan should kick in around 180-200 deg or when ever it thinks its hot. Mine will come on when cold,shut off and then come back on around 180.. the noise should be vary noticable when the fan locks in. like driveing 55MPH with the windows up or down....

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Air filter gauge is showing 10 on hard pulls, (I don't think that is high). Red line is 30 on the gauge. Stats are new. About three weeks ago, a clamp between the turbo and cooler broke, blowing the tube off. I did notice a small amount of oil in the tube. I wonder if there is enough oil in the cooler to block the tubes up? Causing lower boost. As for the fan test, do you put the cardboard between the rad. and the fan? and does that direct the hot air to the fan hub? do you rev the motor up?

Let me tell you what the manual tells about test of the clutch. With the cardboard with the hole in it and that should be on the front of the rad and the 4" hole should come out in front of the temp sensor which is in the middle of the clutch.Run untill the clutch can be hear engaged and dont let it over heat. When the clutch is engaged to max it should be running 80% of the pulley speed. Check this with a photo cell tackometer and a reflector tape on the pulley and a reflector tape on the fan.If it does not engage and the heat gage has been tested and still heats then use a temp gun and check the top rad hoses to see if you have a flow of coolant that matches the temp in the block. If not then check the water pump pressure at a port below the termostats.I dont know what pressure it should be but will be more than 15 maybe 20psi.If not then check water pump.This pressure test is done at rated top rpm.Check for compression in coolant i use a clear pop boddle and fill with water and stick the rad over flow neck hose down in it and withe engine hot then you should have no bubbles.You will have some bubbles till the engine gets hot for a while.A over fueled engine driven by some one that can not handle the hot engine can blow a head gasket or crack a head or liner.

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I'd also suggest cleaning the intercooler & rad. cores externally, either with compressed air or with a pressure washer. I've had heating problems that were caused by partially plugged fins on the cooler & rad.. It also seemed that when air flow through the cooler & rad. are reduced, the fan clutch did not sense a high enough temp to kick in even with high water temp, but once things were cleaned out and proper airflow was restored, the fan clutch worked properly again.

You should remove the intercooler and clean it and the rad. separately, as it is difficult to clean them properly with one in the way of the other.

.

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I'd also suggest cleaning the intercooler & rad. cores externally, either with compressed air or with a pressure washer. I've had heating problems that were caused by partially plugged fins on the cooler & rad.. It also seemed that when air flow through the cooler & rad. are reduced, the fan clutch did not sense a high enough temp to kick in even with high water temp, but once things were cleaned out and proper airflow was restored, the fan clutch worked properly again.

You should remove the intercooler and clean it and the rad. separately, as it is difficult to clean them properly with one in the way of the other.

.

I had an older V-8 that I did that to and it worked. I already tried that by taking them apart to clean them with no luck.

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I had an older V-8 that I did that to and it worked. I already tried that by taking them apart to clean them with no luck.

Bro I really think ya need to check for boost leaks!Any hot 500 I have worked on put out 30- 34 psi boost If your putting out 600 plus you can't do it with 27 psi, ya better have a look for boost leaks!pyros likly heating and the inter cooler can't keep up!Beleive me your barely 450 at 27 psi.

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Bro I really think ya need to check for boost leaks!Any hot 500 I have worked on put out 30- 34 psi boost If your putting out 600 plus you can't do it with 27 psi, ya better have a look for boost leaks!pyros likly heating and the inter cooler can't keep up!Beleive me your barely 450 at 27 psi.

dude i agree it seems to be a boost problem......but dont rule out a head gasket.

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Is it running hot or does the thermastat just say so if so that need to be replaced check your coolant and check for leaks

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