I have a 1997 LT 4x4 Blazer with 150k on it. When I stop and let it idle the oil gage bounces big time up and down and and very fast as well like a trigger or something. It also runs kind of rough as well the oil never drops under 20 and bounces between 20 and 40 any idea what it could be or what is causing it??? I do not remember it ever doing this in the past but you know how memory can be.

 

have you checked the oil level?

 

the sending unit is bad,they are known for this to happen,and happened to mine. Replace it. As for roughness it could be a number of things. Egr,tune up,iac,etc

 

Oil is full and has been changed just recently as well I have replaced the manifold Gasket in the last three weeks. Can you tell me what does it intail to change the sending unit is it called the oil sending unit. I have also replaced all the oil cooling lines no leaks on it.

 

It is called the oil pressure sending unit. The easiest time to replace it would have been when you replaced the intake manifold gaskets as it was right there. Now you are going to have to get a deep socket that fits the new sending unit (should be same as the old) and then get back there and have at it. It isn't a fun job and you have to work partially blind, but it is possible.

 

I just recently posted about the intake manifold gasket needing to be replaced. this was great that i read about the "oil pressure sending unit" is there any others minor/major items that should be addressed when i do pull it all apart?

thanks!!!

 

wow ok thanks guys I sure wish I had said something to the guy that did my intake now GEESH Oh well life continues right