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Turbocharger Replacement

Mazda Service replaced my defective turbocharger and did not change my oil or oil filter. They never diagnosed why my turbo failed the first time. Oil starvation/engine sludge was the cause. Because Mazda Service didn’t change the oil or correct the sludge problem, my turbo repair/replacement ($3,000) failed again in 12,000 miles.
The dealer said they did nothing wrong and only needed to top-off the oil. EVERYTHING I google, YouTube or ask mechanics…all say you must change the oil, oil filter and air filter.
I cannot get Mazda to supply me with the official process for replacing a defective turbo. Honeywell told me when you replace the turbo without changing the oil, it’s like changing a babies diaper and not wiping the babies bottom. Yuck!
How do I get the steps of replacing a turbocharger so I can hold the dealership accountable for not doing the right thing, instead of telling me I’m wrong and go fly a kite?

Without knowing exactly how this vehicle has been driven and how it has been maintained by the OP, I don’t think that it is possible to provide comments with much value.
At this point, I am tempted to say that the OP has not changed the engine’s oil often enough–both before or after the turbocharger replacement–but I won’t be fully confident about that theory until he tells us the following:

Model year and odometer mileage of the vehicle
Whether it was purchased as a new vehicle, or as a used one
How the vehicle is typically driven (mostly local, short-trip driving/mostly highway/a mixture of the two)
How often the oil has been changed, in terms of both odometer mileage and elapsed time
How often between oil changes the OP has checked the oil, and how often it was necessary to add oil between oil changes

So dealer did not do this stuff u complain about? So you did it? Sounds like you are not maintaining ur car.

This is going to be a tough one. It may boil down to your word of what happened against the dealer’s, with something like small claims court being your only recourse.

I agree that changing the oil and filter after a turbo failure is important. But what I or anyone on this forum thinks won’t be of value to whomever is arbitrating your case.

As VDCDriver noted, it would be helpful for you to provide the year and mileage for your car. Also important to share is if you’ve changed the oil per Mazda’s recommended service intervals.

How many miles are on this car? At what intervals did you change the oil?

I agree with VDCdriver - answer those questions.[quote=“kevin.weisinger, post:1, topic:97648”]
Oil starvation/engine sludge was the cause

If you already had sludge before the first replacement, then they did you a favor by replacing it no charge. I wouldn’t expect they would do it again. That is a case of owner neglect. But we’ll know more once we see how you kept up with the necessary maintenance.

…bearing in mind that those recommended service intervals are expressed in terms of both odometer mileage AND elapsed time, with an either/or, “whichever comes first” proviso.

For reasons that I can’t quite figure out, a lot of people focus only on the odometer mileage factor, even though the elapsed time factor is just as important.
In fact, with a car that is driven in mostly local conditions and which accumulates miles very slowly, the elapsed time factor is probably more important than odometer mileage when it comes to how often the oil should be changed.

I’m inclined to agree.

I do not know if kevin.weisinger changed his oil as required or not. None of us know that.
But what we do know is that he came here down on his luck asking for help.
[U] Is it better to start our replies to him with an assumption that he’s guilty or to try and help him?


IMHO asking the OP for the information requested is very appropriate. Openly wondering if the engine has been neglected could, if it has, be more helpful to the OP in the long term than any other suggestion.
Knowing the year and mileage is downright necessary. I’d like to hear from the OP on this.
Knowing how often the OP changes AND checks his oil is just as critical. As is how much oil the engine is using.

If I were working on someone’s car for this problem, these are the first questions I’d ask. Can’t help anyone in a meaningful manner without some background information.

Almost all turbocharger failures can be traced to lack of oil; meaning low oil, no oil, or infrequently changed oil leading to oil sludging or coking.

I would guess that if your turbocharger failed due to lack of oil changes then the rest of the engine is not much better off.

I agree that the oil and filter should be changed during a turbo replacement. However; changing the oil and filter on an already sludged engine is not going to make any difference in regard to the life of the replacement turbo.

Even if they had changed the oil/filter odds are the turbo would have failed again in 12k miles anyway.

Now the question. How many times have you changed the oil/filter since the turbo was replaced and how often do you check the engine oil level?

Unless we are given the necessary background (by answering the entirely reasonable questions that I posed), how could we provide “help”?
I may well wind up taking his side once I know more about his plight, but at this point I don’t think that anyone other than the OP is aware of the information that we need in order to provide helpful advice.


I just looked up the turbocharger replacement procedure for a 2012 Mazda CX-7 and it states to replace any coolant lost during the process, but makes no mention of changing the oil. It would appear that technically the dealer is correct if the service manual is to be the final ruling. However, when replacing or repairing a turbo, I always recommend an oil change service.

But, as you state, the cause of the turbo failure has been determined to be caused by a sludging problem. In that case, I would have to say that he failure(s) are the result of the engine being low on oil, not having the oil changed frequently enough, not using the proper oil, excessive boost resulting from hard driving, or any combination of these things. None of which are or should be warrantable. I think you were lucky to get one turbo for free.


I wouldn’t guess the turbo replacement procedure would spec to change the oil as part of the job. but if a known oil problem existed, it would be common sense in my way of thinking to fix that as part of a any turbo replacement, given that the turbo function, the gadget spinning so fast in order to do its job, is highly dependent on proper lubrication. What the shop should have or should not have done depends on what exactly was communicated between the two of you, and the written work order you signed. For example if you said you only had so much $$$ to spend, that would play a factor is what their plan to repair the car for you.

fyi, if you are interested in some practicalities involved w/turbors, there’s an interesting article in what I recall is the January 2017 issue of the magine Hot Rod where they attempt to install a frugal version of a turbo, with much difficulty. But it’s a good read b/c you can learn from the problems they had to overcome a little more about how it all works, and what turbo control functions are critical to getting the performance you want, like waste gates, etc.

btw, I expect you already know this, but “turbo” and “low cost repair & maintenance” don’t belong in the same sentence. There’s a price to pay for the extra performance.

Mazda service are the experts, not me. Worst case scenario, they should have informed me that oil sludge caused the turbo to fail. Even though the Mazda CX-7 has a known oil sludge problem and an "F"ed up PCV valve configuration (to the Mazda service shops…not Mazda owners) on the 4 cyl turbo (hence they stopped making the CX-7), I paid $3,000 for not changing the oil more regularly. My bad, but I paid the price.
Mazda should have diagnosed the problem, cleaned out the sludge and informed me to follow a specific regiment of maintenance tips, ie more regular oil changes. I was already using synthetic oil. Most of the mileage was interstate and my wife drove it 150 miles to and from work daily or about 850-1000 miles weekly. Am I supposed to change the oil every month or 12 times a year?
Stop blaming the owner and tell me what should have been done by the Mazda dealer. I don’t tell my doctor what needs to be done…he…she…tells me what I need to do. They are the expert.
After the rebutle I just gave, don’t tell me what I did wrong, because my problems should have ended after I forked out $3,000 to replace my defective turbo. Mazda didn’t tell me my arteries were clogged and to start eating more healthy and to get more exercise, they just put a stint in my artery and sent me home. The doctor diagnoses the problem, repairs the problem and provides a preventative maintenance program and so should a professional mechanic. Now I have a car with no engine or turbocharger.
Now…blame me.

See below…

“Definitive Guide for Your Mazda CX-7 Turbocharger”.

The above procedure outlines the specific steps when replacing a defective turbocharger in a Mazda CX-7.

Bob Moore Mazda Service in Oklahoma City, did not…

  1. Diagnose the problem and repair it.

  2. Change the oil

  3. Change the oil filter

  4. Change the air filter.

The procedures outlined above are specific, detailed and clearly defined. Do mechanics not have a procedure manual like this one to guide them through most every repair or are mehanics born with an inate ability to fix anything by flying by the seat of their pants?

I’m Sick and Tired of mechanics hiding behing the “it’s your fault” methodology of why your car blew up…it’s not mine!

I’d love to hear your thoughts on replacing a blown turbo with shards of metal and plastic pieces floating in the old contaminated oil, when all they had to do is follow the procedures outlined in the link provided.

Since they charged me $3,000 and handed me an invoice 3 pages long, do you think I would have told them not to change the oil that would added $40-$65 additional cost to my invoice, especially since that’s what caused the failure in the first place and I needed a damn oil change anyway? I even told them to change the oil and they didn’t. OMG!
They should make everyone change the old crap oil, because if the turbo fails within the warranty period for the replacement turbo, they are on the hook for another turbo repar at their cost.
They changed the fricking spark plugs…and not the oil. They had the car for 7 days. Mechanics are drivig me CRAZY!

Car manufacturers usually publish a factory shop manual for every car they make. Each version covers – usually-- just one model year. All the procedures are in it, step by step. The shop techs who do the job however don’t have the manual for your car to access. But they have a sort of abridged version, probably on a computer data base. What model year is your CX7?

BTW, one thing you could do to improve your odds is purchase that manual and next time you could give it to the shop techs so they’ll have the necessary info straight from the horse’s mouth.

I can’t disagree with your comment that the oil and oil filter should be replaced when changing out a turbo, and the old oil should be sieved for metal debris too… That’s how I’d do it if it were my car. Quantifying sludge isn’t as straightforward, but changing and sieving the oil wouldn’t take much time. I’m just a diy’er tho, not a pro mechanic.

You still haven’t said specifically how often the oil was actually changed.
The link is not the official Mazda procedure for turbo replacement.
It is just a write-up by an enthusiast. The dealer is not obliged to do all those steps.

Thank You!

Thank You for understanding my desperation and trying to get a reasonable response to an unreasonable situation. I’m so tired of being attacked and being the bad guy.

I’m not asking the dealer to pay $11k to replace my motor and turbo, just make me a reasonable offer to help. Split it with me…anything but…“We’ll just have to agree to dissagree???” Bob Moore COO. Are you kidding me???

I’ve been fighting this for 2 years and all I’ve gotten from Mazda Corp. or Bob Moore Auto Group…“It’s your fault for not changing the oil every 3,500 miles.” Yes…and that cost me $3,000. I’m fine with that.

I provided countless youtube how to videos, google search results and not one says to top off the old…potentially contaminated oil after replacing a blown turbo. Why would any mechanic take that risk??? Why put a clean diaper on a soiled baby? Clean the baby first. Is that not reasonable?

If my CX-7 was repaired properly the first time, does anyone believe after 12k miles of interstate driving, (the oil level was always full) my SUV would have blown the dip stick out, causing my oil to blow out into the engine compartment, causing my engine to seize and turbo to blow…again?

I use synthetic oil, but lets agree it was a blend. If starting with a repaired vehicle and the oil sludge issue addressed, could a catastropic loss of engine and turbo happen after just 12k miles…all things being equal? Anything can happen, I get that, but COMON’ Man!

The problem was I received my car back with the same oil sludge problem that I towed it to the dealer for. Thats why all hell broke lose 12k miles later…not because I didn’t change the oil twice in 12k miles. (In a resonable car owner’s opinion…I’m not a mechanic) Does anyone believe I wanted to destroy my car? I thought I had synthetic oil as I requested and believed I was good for 10k-12k miles. I have been driving for 45 years without any major mechanical issues. I actually race stockcars. Mom raced NASCAR 1957, Dad owned his own Ferrari and was an SCCA champion. I can tell you what a car needs to dial it in, but I’m no crew chief.

I posted a video on YouTube of me turning a few laps at Texas Motor Speedway in Fort Worth earlier this year.

If interested, search for “Texas Motor Speedway 184.464” and you’ll find it.

Thanks again for sticking up for me.


That explains a lot.

1 Like

Yup. Combined with other statements in the thread, including using the vehicle to run laps at the speedway while never changing the oil, like this one

the thread explains a lot.

If you brought to car in to get the turbo changed and not to diagnose the root cause of the problem (what exactly did you tell them when you brought the car in?) than the onus is on you. If you asked them to diagnose and correct the root cause of the problem, they should have told you it was neglect and possible abuse.
Should they have cleaned the sludge out? That depends on exactly what you told them to do.
Should you yourself have addressed the sludge issue? Yup.
Should you be running laps with your car at the track without paying attention to its fluids well beyond whet the normal driver does? Absolutely not.

Sorry, Kevin, but IMHO this one’s on you.