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I have been encountering a problem where my truck is running warmer than usual. Just cruising on the highway its sitting slightly above 190, the average temp. When im on it it spikes up towards 210 or so and slowly creeps back down to above 190. Towing its around 210. I just replaced the air filter, changed the coolant and oil as well. Still is doing the same. I was thinking boost leak but cannot find and evidence that it will cause you motor to run warm. The trucks does not have the power or boost that it did before this started and i can hear a hissing when the turbo spools.

What would be a good place to start?

Thanks,

Steve:confused013:
 

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A boost leak would definitely cause the engine to run warmer since less boost will increase the EGT's, and sustained EGT's will affect the engines coolant temp. And hopefully you're keeping an eye on your EGT's so they dont get to hot. Usually a boost leak will cause excess or unusual exhaust smoking upon acceleration and strange hissing or whistling noises when the boost builds. If you know what your normal running boost and EGT's are then you should have an idea how bad the leak is, if you have one.

The rubber inter-cooler boot clamps are common to come loose and allow boost leaks. Sometimes they pop loose too but under stock boost levels they usually just let a little air escape the seal. Make sure all boost boot clamps are tight. There is also a spot where the bottom boots come close to the body and can potentially rub a hole in them when they expand. If you cant find anything obvious then you may have to make or purchase a pressure tester. Dont bother revving the engine in the driveway either since you'll only be able to build about 2 psi of boost in neutral. A boost tester is the only way to see whats going on with around 20 psi sitting still.....and the engine off.

This isn't to say that its positively a boost leak but that there's nothing else to cause boost to decrease while EGT's increase. One factor would be to know over how long of a period of time has this problem happened. Suddenly happened or getting worse over time? :thumbsup:
 

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Uh! start by raising hood and lookee see. Generally changing the air filter and oil change don't fix, you really got problem.
Yes, check boot clamps and boots on intercooler parts for damage/loose.
Even better for overheating is check for restriction to air flow through radiator. Unit known to allow oil vapors from breather to get into rad fins and cut air flow. Most of time is very difficult to see. Even bugs in AC condenser can effect.
 

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Uh! start by raising hood and lookee see. Generally changing the air filter and oil change don't fix, you really got problem.
Yes, check boot clamps and boots on intercooler parts for damage/loose.
Even better for overheating is check for restriction to air flow through radiator. Unit known to allow oil vapors from breather to get into rad fins and cut air flow. Most of time is very difficult to see. Even bugs in AC condenser can effect.
You beat me to it. I second checking the radiator. My truck has the same issue right now and I looked at the radiator and the back of it looks very clean but the front is covered in that evaporated oil from the engine vent. Next thing on my to-do list is to get the stuff for the crankcase breather mod and then remove and clean the radiator with some degreaser and a little water pressure.

This should also help the a/c run a little better too.

A boost leak is possible but is it possible that the "hissing" noise is the fan clutch being engaged. If the fan clutch is engaged then the truck will feel a little doggy just because it is using some extra power to turn the fan.

Good luck and let us know what you find. :thumbsup:
 

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Your radiator is possibly covered in oil. It is highly likely if you haven't cleaned it. You won't see it unless you loosen the fan shroud. Solution is to pull radiator and degrease. Cleaning in place is a waste of time.

You can make a boost boot from plumbing supply parts to test for boost leaks. Just google. Lots of ideas/details. Cost is ~ $20. You need access to air to use it.
 
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