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
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
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
VERIFY CONCERN, CHECK FOR LEAKS NONE, ENGINE RUNNING COLD,
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
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???