Richardx2

I have a 1995 C1500 powered by a 5.7L TBI. Recently I replaced the intake manifold because the old intake was leaking coolant at the water jackets. I found evidence that there some moisture inside the valve covers so I removed the valve covers and cleaned them and replaced the gaskets.

Prior to replacing the intake the coolant temperature gauge would climb to 215 degrees and hold there for a few minutes before the thermostat would open and then the coolant temperature would drop back to around 180 degrees. I talked to a few others and a couple of them said that drilling a 1/8th inch hole in the thermostat would allow water to flow through the thermostat and help keep the coolant temp from climbing too high.

I drilled a hole in the top of the thermostat and now the engine stays cool but the coolant temp never climbs above 180 degrees.

The engine has less than 1 hour time on it and there is evidence of moisture inside the valve covers.

I have replaced thermostat without a hole drilled in it and the coolant temperature climbs up to 215 degrees before falling back to around 180 degrees. The coolant system is clean and does not have anything in it that would clog it up.

Was the engine running too cool allowing the moisture to remain in the engine?

I am running Delo 400LE 15W/40 engine oil because the truck has 178,000 miles on it.

Is there an oil that I can run that will help prevent the moisture or was the engine running too cool?

Thanks for those who take the time to read and reply.

in2pro

The temp climbing and then dropping is normal but it should't drop a whole lot,that's the thermostat doing its job of opening and closing to hold the engine temp steady, are you using a 195F thermostat, that should be the factory OEM

Did you change the oil after doing the work, any water still in the oil pan is going to continue to boil up and put moisture on the valve covers until its removed...are you having to add coolant? if so you may still have a leak that needs to be addressed..

Richardx2

I have not changed the oil yet, and there is no loss of coolant. I have just ran the engine enough to ensure that the leak was fixed. I am not driving the truck until I feel comfortable with the repairs already performed. I have a 195 OEM thermostat installed without any modifications (holes in it). I think that I need to remove/clean out the valve covers again then change oil.

I just got through installing the OEM 195 degree thermostat and the coolant temp seems fine. Any recommendations on which oil to use?

sledge.impy

Who checks there valve covers for moisture?

Is there a PCV valve on your vehicle? Is it plugged up?

Why is there Moisture in the valve cover

Richardx2

There is a new PCV that is functional and properly connected yet when I removed the oil fill cap cover on a routine check I found the milky white substance that means there is moisture mixed with the oil. You don't perform a visual inspection on repairs to ensure that everything functions correctly? Why would you not do a visual check that takes no effort yet could reveal a problem? Any suggestions?

sledge.impy

Can you post some pictures of the extent of the substance?

I've never checked valve covers so I wouldn't know what is normal operation range.

Are you in a cold or humid climate with lots of moisture? This winter has been tough. Do you get a lot of moisture out the tailpipes when starting the engine?

When do you plan to change the oil? Is your dipstick clean?

I think one time I had a head gasket issue and I ended up with cakey oil. That wasn't pretty.

Richardx2

At this point and time I cannot post pics due to batteries dead in camera and the recent snow, I am snowed in.

I am in north east arkansas where it is currently cold and the humidity usually runs between 80-85%.

The amount of moisture that exits the tail pipes is not excessive and after the engine runs a couple of minutes there is no evidence of moisture coming out of the tail pipe.

Dipstick has no evidence of moisture and will change oil as soon I can get the supplies.