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2007 dts
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Discussion Starter #1
The oil pressure drops from 60 psi startup to close to zero in less than 4 minutes. Plenty of new oil at 7.5 quarts and new filter.
The oil sensor was replaced so installed mechanical gage.
The oil can be first be seen pumping by looking thru the oil cap but drops off. The top goes from quiet to a bit noisy.
No change in engine temp.Thinking of replacing oil pump but not sure if Harmonic Balancer can be removed without taking out engine,just a few inches between harmonic balancer and frame. Any ideas or know if oil pump can be replaced with engine in car?
 

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97sls,09dts
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880 Posts
Before you invest some serious cash replace the oil filter with a purolator, or wix/Napa do not use the GM e-core filter. When you remove the old filter a lot of oil should drain out fill the new filter with oil an install recheck pressure with your gauge

The oil pump is not driven by gears it uses a bolt and friction set up also the pump holds a prime when the pump bolt loosens or the pump losses its prime a zero oil pressure can result.

The gentleman over in the Deville forum know a whole lot more about it than I do you may want to check with them.Mike
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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67,179 Posts
LHRAY, Find the GM service manual torque-plus-degrees sequence for your harmonic balancer bolt. If for some reason that torque is incorrect the oil pump, wrapped around the crankshaft snout and driven by balancer bolt clamping friction, spins slower and slower as engine temp increases. Most times a simple proper re-torque procedure cures the problem. If you or a shop does the job, the flexplate must be locked to prevent engine rotation. There are special tools and procedures for this.

For info and instant gratification, subscribe your car to www.alldatadiy.com : The GM service manual plus a LOT more.
 

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The oil pressure drops from 60 psi startup to close to zero in less than 4 minutes. Plenty of new oil at 7.5 quarts and new filter.
The oil sensor was replaced so installed mechanical gage.
The oil can be first be seen pumping by looking thru the oil cap but drops off. The top goes from quiet to a bit noisy.
No change in engine temp.Thinking of replacing oil pump but not sure if Harmonic Balancer can be removed without taking out engine,just a few inches between harmonic balancer and frame. Any ideas or know if oil pump can be replaced with engine in car?
I have 2007 Cadillac dts I think I need a oil pump, took valve cover off started car no oil pumping up top also making loud knocking noise
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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67,179 Posts
Welcome to CF !!!

Please read Post #3 in this 7.5 year old dead thread that you found.

If the engine oil level is correct and the filter is correctly in place, has anyone done anything to/with the harmonic balancer? That balancer bolt torque setting is what drives the oil pump sleeve - clamping friction. Improper torque = no oil pressure. #11 in the diagram.

Use the correct year GM/Cadillac/Helm service manual for correct procedures. You can NOT wing this operation. www.alldatadiy.com is the online GM/Cadillac service manuals.

If the engine is already knocking loudly I'd bet you're in the very expensive overhaul business already.

oil pump exploded.gif
oil pump removal.gif
 
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