There may be a small leak from the oil pan gasket on my 2004 chevy blazer.

Some folks are suggesting that I tighten my oil pan bolts a little bit. I spoke with a dealer mechanic who said that on older vehicles which use cork, this was an effective practice, but on "newer" vehicles such as this 2004 chevy blazer, the gaskets are now made from rubber or a polymer, and this tightening often causes cracking of the gasket which will make the problem .

My question is: can I harm my vehicle by tightening the bolts on my oil pan gasket? Am I likely to harm the oil pan gasket by doing so, such as by inducing cracking of the gasket?

A quick response would be appreciated. Thanks very much!

 

I'm not an expert, but I'd say your mechanic may be correct. Polymer gaskets do get more stiff and brittle as they age, and over tightening could certainly cause additional damage.

That being said, on my truck I had some minor weeping from the oil pan gasket, and after investigation I found that some of the oil pan bolts were little more than finger tight. I tightened them back to factory spec, and it didn't seem to make anything worse, and may have slightly reduced the weeping. I would say if you choose to tighten the bolts, be very careful to not overtighten them and be prepared to have to replace the gasket if things go poorly.

 

Actually, I would like to add to this: If I cleaned my oil lines and oil pan, and now I see that the oil lines themselves are now somewhat black and shiny (I would compare this to a sponge having some water in it) and there is a bit of wet oil on the oil pan, does this indicate one way or the other regarding where the leak is occurring?

 

The remote oil filter & cooler lines are very prone to leaking, so this definitely could be a source of leaked oil. Your oil pan gasket may or may not be also leaking.

 

Replacing leaking remote oil cooler lines is almost a right of passage for Blazer owners! LOL

 

I believe I have to change one or the other oil lines every 3-5 years. Good news is if you buy from AutoZone they come with a lifetime warranty. As long as you keep the old ones you'll never have to buy them again. Pretty straight forward to change them out, just a PITA for the rear one getting it back in. Just make sure you have plenty of extensions to get the bolt out and back in where it connects to the block.