Expert: Rob Painter - 4/19/2011

Question
QUESTION: I recently had a cracked oilpan replaced on my 2001 Cadilac Deville.I don't think they primed the oilpump before starting the car.I think they just changed the oilpan and put oil in the car and started it.Is there a way for me to prime the pump without removing the engine again? My low oil pressure light is on and also says stop engine.

ANSWER: Hello,

Oh boy, you have a problem. The way I used to prime an oil pump was to take it aprt, pack it with vasoline and put everything together and never had an issue. If the pump lost its prime, I am not aware of any way you can get it back without disassembly and worse yet, with the engine running without pressure, you are burning up the cam bearings, main bearings and rod bearings and it won't be long before the lower end of the engine is junk.

The reality is that the oil light comes on usually when it is too late anyway because usually 4 pounds pressure sets the light off. You should have at least 30 psi on a warm engine.

For the oil pump to loose its prime, all the oil must have been out of the crankcase and when running was sucking air (cavitating).

If there was any question, the oil pump should have been changed or primed, but this damage could have already been done when the engine was shut off with the hole in the oil pan.

Even if the oil pan is removed again, the rods and mains with the crank now have to be checked for damage. It doesn't take but seconds of running to destroy the lower end of the engine with the oil light on.

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---------- FOLLOW-UP ----------

QUESTION: Do you thank I should have my headgaskets done, and timing belt with the new oil pump.Because the does have 106,000 miles on it.Most important how much should I look to pay?

Answer
Hello,

I would have a serpentine belt changed and I do not know the cost. Call around for estimates. Unless you over heated the engine, there is no reason to replace head gaskets and if you over heated and head gaskets are blown, the engine may be junk. Head gaskets are not a maintenance item.

If the lower end of the engine is still good, change or prime the oil pump, change the serpentine belt that runs the alternator, water pump etc.

As for the timing belt or chain, I would not worry about it for another 50,000 miles.
These engines last a long time as long as they are not over heated.

I had a person last week asking about a replacement engine from a pick and pull junkyard. I warned him that its not a good idea to get a engine from a junkyard where it can't be run first to check for a overheating issue because 9 out of 10 junk yard engines are junk because the engines were destroyed by over heating.

This is a great engine for performance and mileage. I have seen these engines go to 300,000 miles.

Its so common for people to continue to drive these engines hot and once that light is on aluminum components to the engine are melting. I use the example of having a bon fire and throwing an aluminum can in it. The can melts within seconds. That is how these aluminum engines react when exposed to over heating. At minimum the head gaskets blow. The block may crack and the heads may crack and this is only a result of over heating and not the cause.

If your lower end of the engine is not destroyed from lack of oil pressure, I would recommend replacing the oil pump, packing it with vasoline to prime it and if the engine is not knocking, just change the serpentine belt on the outside of the engine and you are good to go.

Good Luck!

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