What are the symptoms of Caterpillar diesel turbos that have overheated in a Peterbilt?

I'm buying this truck and need to know . Thanks|||I've been working on diesel engines going on 30 years. A turbo does not over heat in these types of installations without causing damage to the exhaust manifolds, pistons, heads, and discoloring the block. Most pistons are limited to 1350 degrees f, while turbos can handle temperatures just above 1625 degrees f. Axial free-play is allowed, but torsional free-play in the turbo should not allow it to have the blades strike or rub on the case. today's turbo in these engines run around 100k-125k rpms.


You can shut down the engine too soon (not very likely for a 18 wheeler) and cause the oil to be cooked on the shaft, thus causing the shaft seal not to seal. Major thing to look at is the condition of the compressor and turbine wheel. Also see if oil is burning on the exhaust side or if there is oil in the charge air. You, will also want to check the air intake for the a sign of any dirt that may have made it into the intake.


Pay a independent shop to do a "General health check (dyno run and systems check)" and an oil analysis for $275. That will tell you how worn out the engine is, how well the cooling system is doing, ect.|||Both answers were great !! again thanks

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|||Does it have 1 turbo or 2? Generaly, excessive noise coming from the turbo when runing, especialy when under a load.Such as hard excelleration , loaded truck, if possible. Listen for turbo noise, they turn 30,000-40,000 R.P.M. at full throttle. Also check the amount of boost pressure, approx. 20 to 35 psi., when accelerating , say 1,400 to 2,000 R.P.M.Check for oil leaks, both outside and inside the turbo, exhaust manifold.If possible. When it's been shut off say,1 hour,take off the intake pipe and exhaust at the turbo,WITH GLOVES ON! reach in on both sides, hold the turbine shaft and try to wigle, push and pull , checking for too much free play, or clearance.Try calling your nearest CAT service dept. for help, tell them how you checked the turbo, ask for their opinion, most will be willing to help you with further testing. Good Luck.