You are here:

Chevrolet Repair/1992 Chevy Lumina Euro 3.4L Overheating on highway

Advertisement


Question
Winter just hit and now the car overheats on the highway.  It does not overheat in town or at idle when warming the car up.  Changed thermostat and rad cap.  Fluid in rad was full when pulled rad cap off.  Reservoir level is fine as well.  I have not seen the fans turn on, however, should they even be necessary when on the hwy?  Once you pull the car over the temp comes down.

I should also mention that on the last test drive after thermo and cap repl we got back to drive way and let it idle.  The temp rose to 3/4 but not to red.  I floored it and the rev limiter stopped it at 3,000 RPMs or so for a few seconds and the temp came down to half.

No water in oil, no smoke out exhaust, fluid appears to be clean and not bubbly when leaving rad cap off and warming up.  Also no visible leaks from pump.  The auto shops in this small town are backed up several weeks and this is our only car.  Please help.

Answer
MORNG TODD, YOU ARE CORRECT THE COOLING FANS WILL NOT COME AFTER 35 MPH..THEY DO NOT NEED TO. THERE IS ENOUGH AIR RUSHING INTO THE RADIATOR TO COOL THE ENG DOWN..THIS ENG HAS THE 4 CAM SET UP YES ??? I WOULD NEVER REV THE ENG UP AS YOU DID, FREE WHEELING A ENGINE AT THAT RPM IS NOT A GOOD PRACTICE..THE PROBLEM TO ME SOUNDS LIKE A POSSIBLE PARTIALLY PLUGGED RADIATOR,THIS IS JUST A GUESS. IS THERE ANYTHING IN FRONT OF THE RADIATOR GRILLE AREA,IF SO REMOVE IT..IT IS LIKE THE COOLING SYSTEM CAN NOT KEEP UP AT HIGHER SPEEDS THIS USUALLY IS FROM THE RADIATOR, OR FAULTY [T-STAT,WE CAN RULE THAT OUT]...[BUT] NOW FOR THE BAD NEWS,, THIS COULD BE THE STARTING SYMPTOMS OF FAULTY HEADGASKETS..IF THIS IS THE CASE THIS PROBLEM WILL WORSEN IN TIME..SO  TRY TO FLUSH THE RAD REAL GOOD AND SEE IF THIS HELPS.IF THE COOLANT IS REAL DIRTY NOT ON TOP BUT LOWER DOWN IN THE RAD THIS COULD BE THE PROBLEM..LET ME NOW HOW IT GOES AND GOOD LUCK TO YOU,,,TOM..

Chevrolet Repair

All Answers


Answers by Expert:


Ask Experts

Volunteer


TOM SHEETS

Expertise

PLEASE READ ALL OF THIS BEFORE ASKING ANY QUESTIONS. IF THIS CHEVY SECTION IS MAXED OUT.YOU CAN REACH ME IN THE OLDS/BUICK SECTION. Will answer questions from 6:00am to 10:00pm all days [EST][[[ NO DIESEL OR PAINT QUESTIONS]]] will answer all 1965 to present QUESTIONS ON ALL GM'S on mechanics of these cars. Keep in mind i am not there in person i am going on what you are telling me !! PLEASE IF ASKING A QUESTION GIVE ME AS MUCH INFO AS POSSIBLE. THE MORE THE BETTER. SUCH AS YEAR,MAKE,MODEL,ENGINE SIZE. THIS WILL HELP ME HELP YOU. I will not be able to answer all questions because of some situations that i would really need to be there and see things for myself,such as electrical issues. In many cases i would need wiring diagrams. I can also give you an estimate on what the cost would be at our repair shop as an idea to help you. Keep in mind that my answer is ONLY MY ADVICE,ck with your mechanic as well.. >> THANK YOU, TOM..

Experience

I have been a ASE certified master mechanic for over 30 years and certified IN ALL 8 CATEGORIES,[engine repair,engine performance,auto trans,manual trans,clutches,steering and suspension,brakes,electrical systems,heating and air/cond. I am also a state CERTIFIED inspector for over 30 years. I do computer work [pcm]fault codes,pcm flashing,state inspection monitor readiness,repairs on exhaust,fuel service,[injection and carburetor,] charging system problems, running issues,alignments,frame problems,tire balance,struts and of course standard and anti-lock brakes.

Organizations
nys state auto repair industry and ase group.

Publications
N/A

Education/Credentials
high school,4 years of tech school,and many many hours of auto training with many gm classes and aftermarket training classes..

Awards and Honors
ASE MASTER TECH CERTIFIED IN ALL 8 CATEGORIES.NYS INSP LICENSE AND A/C CERTIFIED

Past/Present Clients
MANY CUSTOMERS IN OUR BUSY SHOP.

©2016 About.com. All rights reserved.