Cool sign every morning when starting engine " cool " (green color) sign show. after driving 3 to 5 minutes, this sign is gone. so what should i do? any problem for driving. thanks for your answer.

Copyright © by MUSTGO 2010

If you are in the market for a used car then this is a great 30 minutes inspection guide on how to inspect a car,truck,SUV or van from bumper to bumper.

I will append more tips and time saving inspection HOW TO's on this page so PLEASE bookmark my articles.

Do not forget to give me a positive rating if this guide is helpful to you.

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1)Make the test drive appointment with the seller in the EARLY MORNING hour. Inspect the car when it is COMPLETELY cold.

Cold engine will ran rough during the closed loop cycle (warm up phase). This is the best time to inspect for worn motor and transmission mounts.

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2) RECORD color of all fluid on the vehicle.

DO NOT ASSUME

motor oil is clear to black
transmission fluid is lite pink to dark red
coolant is green or orange for GM Dexcool

Dip a small sample of the fluids on a WHITE printer paper and compare it to any drip on the ground after 15 minutes of warm up time.

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3)Look for oil leak(s) under the car after 15+ minutes of warm up time.

Front seal is inches below the harmonic balancer (center of the pulley system on the crank)

Rear main seal is no visible from the outside (It is where the engine meet the transmission casing)

Front seal and rear seal leak(s) can set you back hundreds on labor.
Some seller will tell you the rubber seal only cost $12 or less (which is true) but the labor is at $90+ per hour.

A top notch professional auto repair shop can complete the job on a rear wheel drive vehicle in under 1 1/2 hours (front and rear seals).

Front wheel drive vehicle is a 2+ hours job.

Once again DO NOT ASSUME

Lite brown to black fluid is motor oil

Pink to dark red is transmission fluid

Compare the fluid on the white printer paper so you will have a good idea on which fluid is leaking.

A manual transmission clutch system can be destroy by only few ounce of motor oil seepage from the rear main seal.

An average clutch job is over $260!!!!

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4)Inspect the color of the exhaust smoke at initial startup.

Few minutes of lite blue or black smoke is OK for high mileage vehicle.
(75,000+ miles)

BLUE smoke is a sign of worn oil seal on the engine head. It SHOULD be clear out after 2-5 minutes of warm up time.

BLACK smoke is a sign of engine is running rich.
You should monitor the smoke level. It should reduce to an acceptable level after warm up 5-10 minutes.

lite WHITE smoke is OK until 10 minutes of warm up time.
If there is WHITE smoke after 15 minutes of warm up time then you should do a coolant compression test to make sure the head gasket able to blown.

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5)Look for miss-match tires

This is a sign for low budget owner or car flipper.

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6)After 15+ minutes of warm up time then take the vehicle for local and highway ran.

Test the car on a hilly road to listen for dieseling (ping) sound from the engine.

WORN engine will produce louder dieseling sound.

A totally worn engine will also vibrate a lot more.
You have to factor is worn motor and transmission mount.

Have your friend drive a second vehicle right behind you to look for color of the smoke during the test drive during the test drive.

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7)On 1996+ vehicle,look for Check Engine or Service Engine Soon light.

MAKE SURE this lamp does light for few second during initial startup.

If there is code stored in the computer then you will need an OBDII code reader to pull the codes.

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8)READ the state emission report carefully!

HC
CO
CO2
O2
NOx

Look for the upper limit parameters and compare to the RECORDED TEST RESULTS.

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9)Check for pull on suspension noise during test drive,

Do the re-bound shock test on all four shocks.

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10) Inspect for damaged or replaced radiator support or hood.

Heavy frontal collision can cause frame damage.

Uni-body vehicle may not show frame damage with visual inspection.

Avoid car that has combination of frontal AND roof damage.

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Check Kelly Blue Book for private seller value and Carfax before making the offer.

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Good luck on your vehicle search and please email me if you have any question or comment on how to improve this inspection article.

Copyright © by MUSTGO 2010