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Greg
Greg, import technician
Category: Mazda
Satisfied Customers: 6860
Experience:  17 years shop owner import
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My daughters cx7 2008 started making a squelching noise on

Customer Question

My daughters cx7 2008 started making a squelching noise on acceleration and wouldn't go over 20mph, I road tested it yesterday it did the same to me but then had no power at all the stalled, it would crank normally start and have a very low rpm and it keeps stalling , is it the Turbo or fuel pump ?
Submitted: 1 year ago.
Category: Mazda
Expert:  Greg replied 1 year ago.
Name is***** goal is to provide you with excellent service – if you feel you have gotten anything less, please reply back,
Is the check engine light ON when the engine is running .
I would do a fuel pressure test first as this sounds like a fuel supply issue .
If check engine light is on when the engine is running see if you can get the car hooked up to a diagnostic scan tool and check for malfunction codes .
Please get back to me with the code if any and reply with the reply box, Not the poor or bad service, this way i can get back to you or suggest another expert if needed.
Kind regards Greg.
Customer: replied 1 year ago.
No the check engine light was not on and she drove it under reduced power, but when accelerated it made a squelching noise like a belt tensioner but it was not a belt noise, also the engine does use two to three quarts of oil in two weeks, if the turbo was bad would the engine still operate properly I know it would not be as fast ? I'm going to look at it again today and I will hook up a scanner
Expert:  Greg replied 1 year ago.
Is the car blowing a lot of smoke out the exhaust pipe .
Do you have signs of engine oil all over the engine and dripping on the floor.
If the turbo was bad it would have less power .
The turbos are known to fail very often on this vehicle due to engine sludge ,very very common issue ,in some cases you could blow grayish white smoke out the exhaust.
Squelching noise on acceleration is sure to be the turbo, typical to have this and no malfunction codes .
Go to a good repair shop or dealer and have this confirmed .its sure to me to be the Turbo ..
if needed please get back to me with the reply button, and not the poor or bad service, this way i can get back to you or suggest another expert if needed.
Your deposit does not pay me until the answer is rated in a positive way,
Not rating or a bad rating does not constitute a refund.
If you are not happy or you have sorted out your problem before the answer then please let me know with the reply button .
Kind regards Greg.
Customer: replied 1 year ago.
Just found a p0101 now it barely fires up
Customer: replied 1 year ago.
In your opinion with the symptoms and a pending p0101 what is you best diagnosis fuel pump, could mass air flow be contaminated there was oil residue in the inter cooler ducts ?
Expert:  Greg replied 1 year ago.
Hi .
Disconnect the MAF and try and start as yours is giving way to much info of too much air intake which means more fuel delivery .so flooding.
So with the MAF sending bad info to the ECM ,the ECM thinks its getting a lot of air which its not so the fuel air ratio is not 14.7/1 as it should be but more like 14.7/10 causing to much fuel too little air ,No or hard start unless you have your foot on the pedal to let in more air .
Disconnect the battery for a few minutes then reconnect then disconnect the MAF and now try to start, if she starts easier replace the MAF .
Still have the turbo checked if you still have low power and the same noise .
Rgds Greg
Customer: replied 1 year ago.
Thanks Greg. Is this dialog still available for the next few days ?
Expert:  Greg replied 1 year ago.
Hi
Yes you can get back to me anytime you need to ,just go to your inbox and get back to me with the link.
Even after accepting you can get back to me without any other payment .
Kind regards greg
Customer: replied 1 year ago.
I'm going to have it towed to my home so I can spend more time on it. Thank you
Expert:  Greg replied 1 year ago.
Hi .
Let me know when you get it home and call me if needed.
Greg
Customer: replied 1 year ago.
Hi Greg I spent most of the day running checks the fuel pressure is 70 psi I can gay the engine to run at 3-400 rpm for 30-40 sec then it stalls so I thought the exhaust might be clogged so I removed the up stream O2 sensor and as the engine runs for the 30 sec absolutely nothing comes out of the empty O2 hole, also there is a lot of pressure coming out of the rear valve cover vent tube , could the turbo be blocking the exhaust flow that much ? Hope you have in site !
Expert:  Greg replied 1 year ago.

Do an engine compression test you may have low compression on a few cylinders due to a possible

bad timing chain , but i'm pointing more towards a bad piston ring issue if you have to much back pressure pressure is coming out the rear valve cover vent .

Other possible issue with this is a blocked catalytic converter as you thought but you checked and cancelled out this possibility .

Check the possibility i gave and get back to me .

Greg

Customer: replied 1 year ago.
Greg I will do a compression check , however what do you make of no exhaust coming out of the removed O2 sensor hole ? Also it all over the Internet about bad VVT tensioners and turbos !
Expert:  Greg replied 1 year ago.

Hi.

Like i said a cat or timing out due to t5he VVT or timing chain

A compression test will confirm this if there is a blockage you will have over pressure on some cylinders

and less on others .

Greg

Customer: replied 1 year ago.
Morning Greg, just did the compression test I get 175/165/150/175 also had it running it stays running with a shot of ether but just as I try to accelerate it starves or don breath and dies
Expert:  Greg replied 1 year ago.

Check the timing something not correct here .

How many miles on this engine ?

Greg

Customer: replied 1 year ago.
56k the O2 sensor that I removed is down stream from the turbo is it possible the turbo is Jammed coursing the engine not to breath, also the high pressure fuel pump is that a possibility I saw that it could be worn at the cam end ?
Customer: replied 1 year ago.
Greg I just confirmed I opened the inlet side of the turbo the shaft has a lot of play is completely worn out is it possible the shaft snapped and the other side is preventing the exhaust to breath ????
Expert:  Greg replied 1 year ago.

Hi .

Like i said these engine suffer from turbo failure , i thought you checked this after i mentioned .

"Squelching noise on acceleration is sure to be the turbo, typical to have this and no malfunction codes"

Good work ..

Greg

Customer: replied 1 year ago.
I can get a turbo on eBay, after I replace it will this engine breath again ?
Expert:  Greg replied 1 year ago.

Remove the turbo first , check the two blades are both still turning or are they blocked /sized .

And yes if nothing was getting past the turbo it will be able the breath again .

Greg

Customer: replied 1 year ago.
The nut came off the intake impella shaft and it turns but a lot of play, the exhaust side I can not see yet !
Expert:  Greg replied 1 year ago.

Its sized by the sounds of that on the exhaust side .

remove and replace .

The compression on #3 is low now when you have it completely removed (Turbo) do another compression test .