2003 Mazda6 Checkup Suggestions

idhaskel

Member
Good morning, all.

I am looking at a 2003 Mazda6s (v6, sport package, 5-speed manual). Anything specific I should be looking for? Any known weak spots?

Also - the car seems to have a little roughness through the upper rpm range under load. Is that normal? I drove a 2005 6s with automatic for comparison, and it did not have that problem. But it definitely changed exhaust note under full throttle.

Does anyone else have anything like that?

Thanks for any advice or tips you can lend, gang.

Also see my post under the Motorsports section - I am looking for AX advice for that car.

-- Ian
 
Whats the mileage?

Got oil change recepits from the previous owner? Can you get a compression check run on the motor?
 
More info on car

Thanks for the reply. Here are some more details.

27,000 miles.
Black, cloth sport interior w/carbon-fibre look trim.
Auto climate control
Power seats
No sunroof
6-disk BOSE radio
Bought new by current owner - has all records.
Good on oil changes.
Small fender bender prior - fixed with body parts only - has receipts for this.
Some road-rash on right side wheels. Cosmetic damage only - but is visible.

I am arranging to get it checked over. He did a 100-point check at a local dealer before putting it up for sale - I am going to another dealer for my checkup. I plan on asking mostly about the engine noise and I was planning on getting a compression check as well. Thanks for the reminder.

I have the basics - I am looking for Mazda6-specific things to look for.
 
Has the transmission fluid ever been changed? What type of oil was being used? Was it the correct viscosity? What oil filters?

Here's a list of all current TSB's and MRI's for the 6.
http://www.mazda6tech.com/articles/maintenance/mazda-6-service-bulletin-list-2.html

Has the car ever seen dealer visits? Has the computer been updated to the latest reflash?

When was the last time the air filter was changed? Do you have access to a scanner to possibly check for pending codes?
 
Thanks for the link, crossbow. The car has been exclusively maintained at the dealer. I did not look at the oil viscosity that closely - I will check next chance I get.

Is there a known issue with the computer on these cars? I certainly don't know if it has been reflashed, but as it is under warranty, I presume I can have that done? Air filter - don't know, but presumably per maintenance schedule. I do not have access to a scanner, but I do have an appointment to have a compression check done (thanks!), and can ask them (dealer) to check for codes then.

I appreciate the feedback very much.

-- Ian
 
Ian,

Also - the car seems to have a little roughness through the upper rpm range under load.

This quote worries me a little. If the car is feeling odd at higher rpm's, it could be an issue with the improper oil (wrong viscosity) as the VVT system is based on oil pressure. Restrictions in the air stream could also cause issues (dirty airfilter).

The compression test will reveal any possible issues with the bottom end. So thats a good thing to do.

You might also consider a UOA
http://www.blackstone-labs.com

UOA or "used oil analysis" can detect irregularities in the engine from leaking gaskets, unmetered air, abnormal valvetrain/bottom end wear, or excessive fuel dilution.

Here's some examples of other 6 UOA's for comparison.
http://www.mazda6tech.com/articles/maintenance/used-oil-analysis.html
 
Roughness questions

Now that is an interesting idea - you are scaring me. I don't have time for a UOA, but I have asked the current owner where he had his oil changes done and for the receipts.

The roughness was not just a function of high RPM, but also while under load - which actually probably reinforces your idea. If it is the oil, has there been any real damage, or will replacing the oil with the proper viscosity clear things up?

Are there any tests that can see if the VVTi is working right? Will their computer check do that, do you think? I have an appointment for a compression check and to diagnose the rough running. What are their chances of finding it if it is oil viscosity related?

Thanks again - your input has been invaluable.

-- Ian
 
hope there isn't 91 octane in the gas tank either...
 
Oil changes done at dealer

idhaskel said:
<snip> but I have asked the current owner where he had his oil changes done and for the receipts.</snip>

He has told me that all the oil changes were done at a local dealer (a different one from the one where I am going to have the checkup done). Do I need to check with them to ensure they used the right viscosity? Seems silly...
 
idhaskel said:
<snip>but I have asked the current owner where he had his oil changes done and for the receipts.</Snip>

Spoke to the dealer. Oil used is 5w-30. Not the recommended 5w-20, but still thin enought? Is it possible that is the problem, or can we rule that out now?

-- Ian
 
Is it 5w-30 semi-synthetic, or dino based? The car comes from the factory with semi-synthetic oil.

It should still be fine, (Any 20 or 30wt oil works well in the car) but I'd swap to a higher quality oil when you get a chance in case they were using bulk drum oil (dino based).

The stock oil is motorcraft 5w-20 semi-synthetic, and is very inexpensive, and very good.
 
crossbow said:
Is it 5w-30 semi-synthetic, or dino based? The car comes from the factory with semi-synthetic oil.

It should still be fine, (Any 20 or 30wt oil works well in the car) but I'd swap to a higher quality oil when you get a chance in case they were using bulk drum oil (dino based).

The stock oil is motorcraft 5w-20 semi-synthetic, and is very inexpensive, and very good.

Since the dealer couldn't even get the weight right, I am guessing they can't get the type right either. It is probably dino juice. If I get the car, I will probably update to the motorcraft, or go for Mobil 1 (assuming I can find the right weight). Now to get the thing to the (other) dealer for its checkup.

-- Ian
 
yes the only heavy oil you would wanna run in these cars is the German Casterol*0W-30*. It says made in germany on the back and depending on when it was made the oil is literally green. If gas and oil and spark plugs/wires wasn't the isue did they check the car to see when the last WDS pcm/tcm was done?
 
Last edited:
Da 6,

Its 0w-30 GC. Its near a 40 wt viscosity, which is probably what you were confusing.

gcfront.jpg

gcback.jpg


But he's right, thats about as thick as I'd go in either the 6i or 6s.
 
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