Why are chevys having such big problems with their intake manifold gaskets?my99 malibu,my friend's 94 lumina and 2000 cavalier and brother's 2002 impala have all had to have the gaskets replaced.
Actually, if you read the back of a bottle of A/C Delco brand dex-cool.... you'll be in for a surprise!civicduty said:I'd like to express my unprofessional opinion ;D that Dexcool is often left in there too long. GM gives a 5yr or 150,000mi life for it, but people seem to only go by the 150,000 miles! (Many people who buy new cars don't keep them that long.)
I seem to recall mechanics here on BAT advise: Change your Dexcool every 3yrs or 50,000mi and it should serve fine. Also don't let the coolant level get low to introduce air into the cooling system.
autodr, thanks for the great explanation of how the nylon degrades in the heat soak, and how the proper ratio of coolant/water is so important. Would an engine with an aluminum intake be fine with pure OAT?
I'd like to ask how the silicates would protect the plastic from heat..?
Yep.... the 5yr/150k stuff is Texaco's idea. They invented that stuff. GM started using it. I understand it because of credits that the EPA issues for things that exceed emission's standards on a 100k mile time frame. Maint. is emissions also (that's why some engines have a 60k mile replacement interval for some states and the same engine will have 105k interval in Mass, Cali. and some others). When the manufacturer makes something that the EPA wants to fine them on, they can apply those credits from other issues toward the fine.civicduty said:Isn't 2yrs/30k miles the same as the old high silicate formula interval? I am quite sure the last GM cooling system I looked at (a 1997 Century) had 5yrs/150k written on it, but I could always be wrong!