94 silverado blowing oil

I have alot of oil running down the back side of my engine. Its a 94 Silverado 5.7 350. I thought it was the intake gasket in the back. I had a guy tell me it could be the oil sending unit. But I looked this up in my haynes book and it says that the sending unit is down by the filter. I cant really tell where its comming from. Any help would be appreciated.

Re: 94 silverado blowing oil

Hi gregs, unfortunately Haynes and Chiltons manuals are notoriously incorrect. They cover too many models, years and engines in one manual and appear to have minimal proof reading. You might as well guess. If the amount of oil is significant it isn't likely the intake gasket. Seems to me the oil sending units on small block chevys are on top and behind the intake manifold, good luck.

Re: 94 silverado blowing oil

Depending on your engine there are two locations<br />1 350 LT [opti-spark] distrubutor on timing cover ,front of engine.Your oil sender is by your oil filter left bank<br />2 350 regular distrubtor and cap Your oil sender is located by the distrubtor<br />Also you might want to check that your valve cover gaskets, that they are not leaking causeing the problem[gravity takes oil down]

Re: 94 silverado blowing oil

Originally posted by SlowlySinking:<br />[QBIf the amount of oil is significant it isn't likely the intake gasket. [/QB]

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Wait a minute here, If the rear seal is lost on the back of the intake, it can be Very significant.<br /><br />They have been using RTV sealant on the front and back for several years and they dont leak normally unless it has been replaced and was not cleaned properly or they used the wrong sealant.

Re: 94 silverado blowing oil

I would clean everything with gunk and a pressure washer then locate the leak. There are a bunch of places oil can leak from. Nothing beats a good visual look.

Re: 94 silverado blowing oil

Originally posted by Bob_VT:<br /> I would clean everything with gunk and a pressure washer then locate the leak. There are a bunch of places oil can leak from. Nothing beats a good visual look.

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Cleaning is good, but there are only four places back there that can leak and you may not be able to actually see any of them. <br /><br />1. Right valve cover.<br /><br />2. Left valve cover.<br /><br />3. Oil sending unit or plug.<br /><br />4. Rear of intake.<br /><br />Had a 65 Corvette 327 that had a major leak back there, cleaned, drove and looked, never could see the leak. Finally pulled the intake,resealed the sender and replaced the valve cover gaskets. Leak fixed, never did know what it actually was. Betting it was the intake though.<br /><br />If you dont mind the cost, (But we all do), you can take it to a shop and they will put a dye in your oil and shine a light behind your engine and the leak will glow. But it will cost you unless they repair the leak for you.