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A new wonderful noise, oh joy! Exhaust leak?

Driving a 03 Mazda minivan. It recently started making a fairly loud audible ticking noise under acceleration.

First thought was lifters just needing a fresh oil change. (Our other vehicle suffers from that about every 5000 miles or so.)

Oil change has not removed the noise. Took it to the dealer, and the skipped the opportunity to tell me I needed expensive repairs.

Ticking is noticeable only under moderate to hard acceleration and is heard after 1500 rpm. Might be there all the time or at lower idle, but drowned out by road noise.

Ticking noise is slightly intermittent as well. Normally hear the noise, but it may go away after some driving unless I hit the throttle hard, ahem, well try to accelerate quickly. It IS a minivan.

No loss in performance. Want to hopefully fix before there is significant damage or big repair.

I don’t think I’ve noticed any exhaust smells in the cabin.

Some water does appear under the van after it sits after being shut off. Mostly under the engine bay. Might be a bit more than air conditioning, but not by much.

No CEL codes.

Any places to start looking? Any likely culprits? Exhaust? Something else?



Water under the engine compartment after running A/C is normal. It is only a coolant leak if it does not evaporate cleanly, but leaves a slippery sweet-smelling liquid after sitting for a while.

If you put it in park and set the parking brake and rev the engine, can you hear the ticking? If so, take it to a good mechanic and he or she can locate the ticking. If it only ticks when it is moving, that is harder to do. Tom and Ray have talked about using wireless microphones with magnets on them that they can stick under the hood in various places to triangulate the noise.

You don’t have to go to the dealer if it’s not warranty work.

A “ticking” noise from the valve train is a known problem with some Mazda engines, particularly as the miles mount up and even more particularly if oil changes have not been frequent enough.

Most drivers seem to think that they change their oil often enough, but in reality, most drivers’ driving patterns actually fit the “Severe Service” description, thus making more frequent oil changes necessary in order to avoid problems. Details on what constitutes “Severe Service” and what type of maintenance schedule should be followed can be found in your Owner’s Manual

But, to get to the heart of the matter, Mazda now has rocker arms of a “revised design” that are available in order to relieve this ticking problem, however I’m not sure how much money you want to sink into this vehicle. You might want to price the “revised design” rocker arms with a Mazda dealer’s parts department, and then get some estimates from independent mechanics on installing them.

You might also want to ask your mechanic about an engine flush. While I normally do not recommend this type of procedure, it might be necessary with your engine.

Do You Know The Sound That Pre-Ignition Makes ? Could That Be It ?

It makes a ticking or pinging (“tinking” or “pinking”) sound while accelerating and can be intermittent.

Mechanics know the sound and you were right that the dealer could have missed an opportunity to sell you something. An October 15, 2004 Mazda Technical Service Bulletin written for Mazda technicians and pertaining only to 2002 & 2003 Mazda MPVs outlines the pre-ignition problem in these specific vehicles and the cure.

The fix is reprogramming the PCM (Power Train Control Module). I’m guessing about an hour labor.

Stop by the dealer an take a mechanic (one with hearing intact) for a test-drive to verify the condition.


It was a gasket in the exhaust system that had died. Combination of a dying gasket, a loose bolt or two, and an engine that expanded slightly when warmed up were what made the noise intermittent.

The gasket was replaced, total cost just over $100. (A $20 part plus about an hour and half of labor), bolts snugged up, and it runs again nice and quiet.


Could It Be Your Camshaft ? Some 2002 - 2006 Mazda MPVs With The 3.0L Engine Develop A Ticking Camshaft (Left Bank Cylinder Head) While Running At Operating Temperature.

Mazda’s put out a TSB (Technical Service Bulletin) instructing technicians in the proper diagnosis and repair of these vehicles.

This sounds bad at first, but it looks to be no big deal, maybe a couple hours of labor and perhaps minor, if any, parts.

Following verification of the noise source, a mechanic removes one valve cover (left one), and the camshaft caps, reinstalls them, torques them all down except cap 4L, does a little “hokey pokey” (as per bulletin) with cap 4L and then torques that one, too. The cover goes back on and Voil?! The ticking noise is history !

I’d have your dealer check it out. They must do quite a few of these. The issue is with the 3.0L and concerns models other than MPVs, also.

Water under the car is a concern. This concern could be totally unrelated to the ticking. A/C drippings do vary with humidity and could be normal, but have everything checked, especially the coolant.


Oops! Never Mind. Haven’t Had A Gallon Or Two Of Coffee, Yet.

On second thought, save this reply for your next “ticking noise.”


Glad it was a cheap fix. I know some models have had problems with the VVT system mucking up and needing replaced