Problem with my 2002 CHEVY MALIBU.
Repairs done prior = ENGINE REPLACEMENT, USED BUT GOOD.
NEW WATER PUMP, T-STAT, INTAKE GASKETS, RADIATOR, HOSES AND COOLANT TEMPERATURE
SENSOR. MULTIPLE T-STATS FROM DIFFERENT SUPPLIERS INCLUDING DEALER. TEMP SENSOR.
RESERVOIR AND CAP. BLOCK TEST.
Question = TRYING TO MAKE A LONG STORY SHORT...
'O2 CHEVY MALIBU 3.1L OVERHEATED AND BLEW MOTOR. REPLACED WITH A GOOD ONE FROM A
BUICK CENTURY. PRIOR TO INSTALLATION, REPLACED INTAKE GASKETS, T-STAT, W/P, PLUGS, OIL
PAN GASKETS AND THE TIMING COVER (DUE TO SLIGHT PULLEY MOUNTING DIFFERENCE) START
AND RUN ENGINE IN BAY AND ALL IS GOOD. ROAD TEST GOOD. RECHECK GOOD. GIVE TO
CUSTOMER AND OVERHEATS IN FIRST FEW MILES. THEY PICKED IT UP THE NEXT DAY. AFTER
RECHECKING MULTIPLE TIMES, FOUND THAT IT ONLY OVERHEATS FOR A MOMENT, PUSHES A
LITTLE COOLANT OUT OVERFLOW, AND GOES BACK TO NORMAL AND REMAINS GOOD FOR THE
REST OF THE DAY.
IT WILL ONLY DO THIS AFTER THE ENGINE COOLS. IT WILL ONLY OVERHEAT ONCE OR TWICE
DURING THE WARM UP CYCLE ONLY, THEN IT'S OK. TRIED MULTIPLE T-STATS, REPLACED HOSES
AND RADIATOR. STILL DOES IT. TOOK T-STAT OUT OF VEHICLE AND IT STILL HAPPENS. AFTER
REPLACING EVERY PART OF THE COOLING SYSTEM MULTIPLE TIMES, IT STILL HAPPENS! LAST
IDEA WE HAVE IS THERE IS A CRACK INSIDE MOTOR THAT ONLY OPENS A CERTAIN TEMP AND
SEALS BACK UP. WE JUST CANNOT FIND ANY EVIDENCE OF THIS. BUT CATCHING IT AT THE RIGHT
TEMP IS NEARLY IMPOSSIBLE. DOES THIS SOUND LIKE A POSSIBILITY TO YOU? I WOULD THINK IT
SHOULD SHOW ON A BLOCK TEST AT ANYTIME BUT IT DOESN'T.
BY-THE-WAY, MY NAME IS MATT. I AM THE SERVICE MANAGER IN JACKSONVILLE, FL. RECENTLY PUT
DOWN THE TOOLS TO TRY MANAGER. 15 YRS IN SHOP PRIOR. 10YRS AT GM DEALER. THE TECH
WORKING ON CAR IS ALSO GM CERT. AND 35 YRS EXP. OWNER ALSO EXPERIENCED AND AT A
LOSS. DO YOU HAVE ANY IDEAS OR SUGGESTIONS?
THANKS FOR ANY HELP, MATT
P.S. LOOKING FOR A GOOD SITE LIKE THIS TO USE REGULARLY. I'M TRYING IT OUT FIRST AND IF IT
GOES WELL, WE WILL MAKE REGULAR CONTRIBUTIONS.
Well, I've go to say right off the bat, this is a head gasket problem. This sure does not sound like the
original problem that blew the engine is still there. The tech may have replaced the intake gaskets because
they were leaking, but the rear head, passenger side corner leaking coolant may have been wet because
of the intake. Easy to miss that. Even if not leaking externally, this is a good sign of a head gasket problem.
Your GM tech should be familiar that the rear head is very common to have a blown gasket.
Most of the time leak externally, but not always. Have seen these exact conditions a few times, as well as
our tech JK. They will overheat once or twice during the warm up cycle, burp, then be fine all day long.
Sometimes you can catch it with the cooling system dye test looking for combustion gases.I would remove
both heads and send them out to have checked for cracks just to safe.
Overheating Engine After Many Parts Replaced