I have a 2007 CX-7 with only 60K miles. Original owner. Recently, it has started making a ratting noise for about 10 seconds on cold starts. I fear that this is the dreaded VVT failure. I stuck my fingers into the oil fill hole and the chain seems loose to me. I cam move it up and down about 1/4" without much effort. On the other hand, I am not sure what it should feel like. Should the chain be under tension when the engine is off?

A local independent shop (Boulder, Colorado) quoted $1500, using all genuine Mazda parts with a 2 year warranty. They also recommend changing out the oil pump chain and tensioners for an additional $500.

My local Mazda dealer will not give me a quote over the phone, and I have an appointment to take the car in, in about 2 weeks.

Does anyone have a recent cost for getting the timing chain / VVT service at a Mazda dealer?

Does $1500 sound reasonable?

I've watched the youtube videos on this job, and I could do it myself. (I've actually rebuilt an entire engine before, but that was before kids and career took over all of my free time). If I decide to do it myself, is there an online source for mazda parts that is cheaper than the dealer? (something like ECS tuning is for Audi parts... but for Mazda) There is an entire timing chain kit on amazon for $90, but using knock-off parts seems like a recipe for disaster in this case. (I don't mind using cheap parts if they are somewhere that I can get to them easily if they fail, but not a timing chain)

How tough of a job is it? Is it do-able in a single day for a shade tree mechanic?

 

I was able to find an OEM Mazda timing chain based on your model. Here it is for your reference https://www.mazdapartsprime.com/oem/...3k912201a.html . Hope this helps

 

I just finished replacing the timing chain on my 2008 CX-7. It's a tricky repair! The Youtube videos helped a lot, but as usual, left out some important details! I had to watch numerous video to get the whole picture. First there's a lot of stuff you have to remove on the driver's side, upper side of the engine. Next, the crankshaft pulley bolt may be VERY hard to remove unless you have a very powerful impact wrench. I had to trap the bolt with a breaker bar and hit the starter to get mine loose. Timing everything is CRITICAL. You have to have the crankshaft, camshafts AND crankshaft pulley all set properly to get the timing correct and ALL THREE must REMAIN in time while you assemble AND tighten everything! MY CX-7 had 136,000 miles on it. So, I replaced the water pump, serpentine belt, idler wheel, spark plugs and associated gaskets. The chain kit came with new sprockets, including a new VVT sprocket, oil pump chain and sprocket. I also replaced the VVT solenoid. It sits next to the VVT Sprocket. I used new crankshaft pulley bolt and camshaft sprocket bolts. To tighten the crankshaft pulley bolt, first, with the crankshaft stop pin in place and camshaft timing plate in place, I torqued the bolt to 35 ft-lbs, then to 90 ft-lbs with a torque wrench. I removed the crank pin and camshaft timing plate. Then I put a tool on the crank pulley to keep it from moving and then tightened the crank bolt more! Essentially, as tight as I could get it with a 2 foot breaker bar! There are NO keys on any of the timing parts. Everything stays together via FRICTION. Replace ALL friction washers, three on the crankshaft pulley and one each on the camshaft sprockets. There are many 8 and 10 mm bolts. Use ONLY 6 point sockets and wrenches to remove them. TAKE YOUR TIME, check and double check everything along the way. Keep all the bolts for each assembly in the part or in separate labeled cups after removal. I labeled with tape each plug too. Be sure you understand what you are doing along the way! My CX-7 is running REAL smooth now and no more chain noise! Goodluck!