My GMC Z71 with the 5.3L engine has 136,000 miles has developed a slow coolant leak. At about 130,000 miles I changed the water pump which was original just as a precaution and the thought that it was the cuprit for the slow leak. Now 6000 miles later the coolant level is low again. I've read that the DEX cool can deterioriate the Intake manifold gaskets but I see no evidence of a leak on the external portion of the intake nor can I see any evidence in the oil that the gasket has failed to the inside of the manifold. Any suggestions?
Look at the engine, you didnt state what year but 2000 and earlier have an egr valve, if you look right below that on the left or drivers side you may see a leak there or on the rear of the intake around the distributor, you will need a good light to see either
March, 10, 2007 AT 11:42 AM
It is a 2000 I have not checked the EGR but will do so, thanks for your input.
March, 10, 2007 AT 11:46 AM
Im sorry I meant below the egr, but I dont think the 01 have it, but look in that location, drivers side right below center of manifold you can see the front and left side of intake, this is usually where they leak, if its not there or in the rear I would start checking the passenger side carpet for coolant