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Curtis B.
Curtis B., Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 28939
Experience:  Technician turned service manager on multiple lines of trucks and engines, used in industry.
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Have a 2012 Freightliner Cascadia with a Detroit dd15 after

Customer Question

Have a 2012 Freightliner Cascadia with a Detroit dd15 after truck heats up oil pressure drops when coming down to a idle when slowing down stop engine check engine lights come on red oil pressure light check oil pressure with scanner under acceleration only 27 PSI has some blow by , this all just started today was running great. Any suggestions or help would be greatly appreciated
Submitted: 2 months ago.
Category: Medium and Heavy Trucks
Expert:  Curtis B. replied 2 months ago.

Welcome to JUST ANSWER heavy equipment. With years of experience, I look forward to doing my best to help.

Expert:  Curtis B. replied 2 months ago.

First thing to check, is the oil for fuel contamination. Does the oil smell of diesel? If it thins the oil, you have pressure loss! If not diesel in the oil, then you need to get to shop and get to checking the oil pump and bearings in the crankshaft.

Customer: replied 2 months ago.
No it's not fuel dilution . No diesel smell I've been researching have seen the oil tubes seals go bad and cause similar problem how can I check to see if this is the problem?
Expert:  Curtis B. replied 2 months ago.

Not sue what oil tubes would be on DD15.?? Suction tube on oil pump? Would have to remove oil pan to check.

Customer: replied 2 months ago.
Would those suction tubes side the blow by and , how do I tell the seals are bad?
Expert:  Curtis B. replied 2 months ago.

Suction tube would let air enter the oil pump, dropping oil pressure, and the only way to know is to physically look at the seals!

Customer: replied 2 months ago.
Ok I will drop pan but do you think that could cause the blow by because there was none before just all of the sudden
Expert:  Curtis B. replied 2 months ago.

If oil pressure is low , it could have already caused engine damage, and the blowby.