My friend has a 93 Chev conversion van with 5.7... poor heater output. He has an aftermarket temp guage that shows engine runs about 125 degrees F. He also told me the Dealership replaced the thermostat and it didn't seem to help. I attached my Snap on MT2500 and confirmed that ECM sees about the same temperature as his guage does. We headed down the road (it was about 35 to
40 degrees F that day) and I watched engine temp fall to about 110 F. Then he shows me this receipt from the dealership which I will quote below:CUSTOMER STATES HE NEEDS A NEW THERMASTAT (yeah, that's how they spelled that) VAN HAS POOR HEAT LAST FEW DAYS. DOES NOT SEE ANY LEAKS ON GROUND AND HAS NOT ADDED ANY COOLANT NOTE: HAS AFTERMARKET TEMP GUAGE, BOTTOM LEFT OF DASH IS ACCURATE VERIFY CONCERN, CHECK FOR LEAKS NONE, ENGINE RUNNING COLD, SUSPECT THERMOSTAT REPLACE THERMOSTAT AND RADIATOR CAP. CAP LOOKS OLD, TOP OFF COOLANT AND BLEED SYSTEM. ROAD TEST. ENGINE STARTED TO COOL OFF ON ROAD TEST, CONSULT WITH 512. RECHECK FOR AIR IN SYSTEM, NONE. SUSPECT THAT THE INTAKE MANIFOLD GASKETS TABS HAVE ROTTED THRU AND LEAKING COOLANT BACK INTO ENGINE. WILL HAVE TO REMOVE INTAKE MANIFOLD CUSTOMER DECLINES, SEE ESTIMATE.
Anyone ever heard of such a thing causing low temp?? ... leaking gasket that isn't dumping coolant outside of engine, nor into crankcase as there is no coolant in oil or white smoke in exhaust?? Can this be just allowing coolant flow that is bypassing the thermostat and keeping engine temp very low??
I'm assuming the dealership really did change the thermostat... "assume" is a dangerous word... but they billed him 288.03 total! Ha! Estimate was $85 (I guess to just see if heat is really poor), then revised to $250.00, then revised again to $299.00 !!!! Below that is another estimate: INTAKE MANIFOLD GASKETS: $495.00 PLUS LUBE OIL AND FILTER: $29.95
at $300 to do the thermostat, I'd guess the intake gasket job would get "revised" a couple times along the way as well??? And experience or thoughts regarding this engine running too cold that can be something other than thermostat bad??? Thanks!