very high oil comsumption PLEASE HELP!

[louieXIII]

I own a 2007 CX-7 grand touring (turbocharged) that was running sluggish. i had the turbo inspected and it basically wasn't working at all (ie full blown malfunctioned). i had the turbocharger replaced and the mechanics said they found oil in the intake manifold and all over the turbocharger. now that it's been replaced, it doesn't run sluggish anymore but it consumes oil like crazy. We put 5 quarts in, drove 1,000 miles, no leak anywhere under the car, and the dipstick is bone dry. my assumption is whatever is suppose to pump oil through the new turbo manifold is pumping way too much or there's an internal leak somewhere else...? any takers? totally lost. ask and i will answer.

took out the throttle body, seems to be dry. took out the EGR. Seems to be functioning properly. no clue what to do right now.

[roguemazda]

get the shop to do a compression test first then come back

[mazdaspeedchris]

If turbo was just replaced its probably not the turbo. Oil consumption that great is usually always rings. Look at the plugs then do the compression check. Good luck

[louieXIII]

The guy that replaced the turbo said he did a compression test in all 4 and said the compression was good. I was on deployment and my wife had a relative working on it while I was gone so I have no idea what was done, looked at, and what wasn't. What I did today was took of the intake manifold (total can of worms smashed open with an axe). Intake manifold has tons of oil residue in it and looking at the intake valves in the head, they all appear to have a fresh coat of oil on them in all cylinders.

[mazdaspeedchris]

If the compression was good then I would look at the turbo. Was this done by Shadetree Mechanics???? Was it a new turbo or rebuilt??? To much consumption to be valve guides. Did the oil consumption start before you had the turbo replaced or after?

[louieXIII]

So I'm gonna go get a compression test kit and do it myself. Then I'll post the numbers here and see what you guys think. Harbor freight got a compression test kit for like 25$. Will post results soon. Are there 2 oil lines that connect to the turbo? My guess is when they connected the hoses it tubes maybe they installed them backwards???? I downloaded the CX-7 workshop manual (all 1700 pages) but some diagrams aren't as detailed as I'd expect.

[louieXIII]

so i did a compression test with the intake manifold not installed. don't see why i would need it in to get an accurate reading. i basically got a variable 70 to 75 psi in all 4 cylinders when i checked it. the manual says i'm supposed to get 185 with a minimum of 129 and a max variable of 28 from highest to lowest. so my guess for what happened is with the new turbo installed and the engine having 92k miles, we just blow out the rings. from my experience, a blown head gasket gives you a peanut butter consistency on your oil dipstick and white smoke out of your exhaust. is it safe to assume that i gotta rip this engine out and replace the piston rings? or do you guys see any reason why i should not have to do that?

[mazdaspeedchris]

Sounds like you have major issues. Try a new mechanic. Is this a stock motor?

[louieXIII]

Yeah it's he stock motor. Pretty sure the new turbo going on a 95k engine blew out the piston rings so I'm just gonna replace that and the head gasket. Will report results in about a week plus. I'll post pics.

[torquemaniac]

Originally Posted by louieXIII so i did a compression test with the intake manifold not installed. don't see why i would need it in to get an accurate reading. i basically got a variable 70 to 75 psi in all 4 cylinders when i checked it. the manual says i'm supposed to get 185 with a minimum of 129 and a max variable of 28 from highest to lowest. so my guess for what happened is with the new turbo installed and the engine having 92k miles, we just blow out the rings. from my experience, a blown head gasket gives you a peanut butter consistency on your oil dipstick and white smoke out of your exhaust. is it safe to assume that i gotta rip this engine out and replace the piston rings? or do you guys see any reason why i should not have to do that?

How did you do the compression test?

You need to crank the engine until the gauge stop rising (you need at least 4 consecutive compression stroke to get a good reading)

[mazdaspeedchris]

Turbo should not have caused any issue but I would be looking at your mechanic!!!!

[louieXIII]

i connected the battery and had my wife crank it for about 10 seconds per cylinder. it never held any psi though. it would pop up around 75 and drop out as soon as she stopped. leaving me to believe the piston rings are blown out.

[mazdaspeedchris]

You said the car wasn't sluggish after the new turbo and the mechanic said the compression is good. compression that low wold give you drivability problems. Are you sure you tester is good?

[frothy]

Originally Posted by louieXIII i connected the battery and had my wife crank it for about 10 seconds per cylinder. it never held any psi though. it would pop up around 75 and drop out as soon as she stopped. leaving me to believe the piston rings are blown out.

Sounds like your compression tester is faulty. The pressure should NEVER drop ‒‒ there's a schrader valve inside of the end that threads into the sparkplug hole to prevent this. If your compression tester has a quick‒disconnect, disconnect it, and try blowing down the tube, towards the threading ‒‒ you shouldn't be able to.

You most likely have a bad schrader valve or a hole in the hose if you're seeing the pressure drop.

If it's a bad valve, you'll likely have to order a replacement online. I've yet to come across a store that has replacement valves for compression testers in stock. You can find schrader valves in a lot of stores for bike/car tires ‒‒ and they'll fit ‒‒ but the spring is much stronger and will result in low compression readings if used.



...have you checked your PCV valve?

[louieXIII]

Originally Posted by frothy Sounds like your compression tester is faulty. The pressure should NEVER drop ‒‒ there's a schrader valve inside of the end that threads into the sparkplug hole to prevent this. If your compression tester has a quick‒disconnect, disconnect it, and try blowing down the tube, towards the threading ‒‒ you shouldn't be able to. You most likely have a bad schrader valve or a hole in the hose if you're seeing the pressure drop. If it's a bad valve, you'll likely have to order a replacement online. I've yet to come across a store that has replacement valves for compression testers in stock. You can find schrader valves in a lot of stores for bike/car tires ‒‒ and they'll fit ‒‒ but the spring is much stronger and will result in low compression readings if used. ...have you checked your PCV valve?

Yeah the pcv is on a panel under the intake. Took it off, shook it and it rattles as it should. I'll try the compression test again though. Never seen anything like that. Also, the engine is dry and I saw online that you should pour a little oil in the cylinder when you do the test to help create a seal.

[louieXIII]

Yeah I took off the pcv. Rattles just like it's supposed to. Faulty tester? It was O'reilly's so I'll try autos ones. I'll also add a little oil into it just cause I saw t helps create a seal. The ending was running dry for idk how long.

[Design]

Sounds like a textbook OCR issue. Might be best to run both a compression and leakdown from a mechanic who's versed in this platform to rule out the upper rings and valves. But we are seeing many more higher mileage stock motors suffering from this issue. We suspect it's a combination of carb accumulation and the early gen PCV design.

Mandinca's Oil Consumption Problem

Mine exhibited the exact same issues. And after extensive troubleshooting we've got it pinned to the rings (needs a teardown to confirm). The cats mask most of the oil consumption. But I'm willing to bet if you remove the plugs, one or more of the piston heads will be wet.

[louieXIII]

OCR? I'm on my way to autozone right after I reinstall the intake manifold. I did the compression test with it removed because I didn't (and still don't) see how it could affect the compression test if the intake manifold and throttle body aren't meant to hold any psi. I'll post my results with the autozone test set shortly.

I'm assuming OCR has something to do with oil. And recirculating it.

[Omega]

Originally Posted by louieXIII Yeah I took off the pcv. Rattles just like it's supposed to. Faulty tester? It was O'reilly's so I'll try autos ones. I'll also add a little oil into it just cause I saw t helps create a seal. The ending was running dry for idk how long.

You add oil to a cylinder with low compression to diagnose if it's a ring sealing issue... You should have decent/even compression without adding oil to the cylinder.

[Design]

Oil Control Ring. The tiny holes tend to suffer from blockages due to soot accumulation. A clogged OCR won't show up in compression/leakdown testing.

[MRR]

if you love the car, fix it. If you don't, trade it in to a MS6 or MS3

[louieXIII]

yeah i already dropped 250 on rings, gaskets and a new vvt actuator to get rid of that cold start rattle sound. i was gonna go get another compression test but after reading that thread Mandinca's oil consumption problem i just said screw it. parts are all supposed to be here friday. getting a cherry picker saturday. gonna be a long weekend. you guys ever take apart the timing chain?

[mazdaspeedchris]

If you are doing rings make sure you check all cylinder measurements and hone the cylinders. Hopefully you won't have to bore them and get new rings. You should replace the bearings as well since you have the motor apart.

[Design]

I might ask, for the benefit of the community, to update this thread on what you find in the teardown. Gunked up rings? Something else? Will probably help quite a few other high mileage owners.

GL.

[louieXIII]

it's 10:30pm. i got 2 motor mounts off, working on the 3rd and 4th. gonna get it ripped out, supported on the floor somehow and start tear down tomorrow. my CV axles were a pain in the ass to pull. 1 we had to beat/pry out with a pry bar and 2 flavors of hammers. the other one (passenger's side) spline got seized in the transmission once we ripped it out.

side note, i talked to one of my neighbors yesterday and he said he had a 2010 cx-7 and it burned out 2 turbos before they traded it in. i'm wondering if it's typical for cx-7s to just have horrible motors or if this is just a coincidental string of bad luck.

[5doorsoffury]

I am confused let me know if i am right....
You had no oil consumption worries UNTIL you replaced the turbo.

The MECHANIC said you have good compression after performing a comp test.

You posted 1 set of compression numbers from a Harbor Frieght gauge that is widely known for being a horriable pos that never works or reads right.

You have done no leakdown test.

Based off this you are pulling the motor......

Just wana make sure i got it right.

[mazdaspeedchris]

I must agree. I went back and read the original post. Harbor Freight SUCKS. Who did the work and did they replace the turbo with a new one or rebuilt?

[Design]

I suspect it's been there all along (oil consumption) and is what caused the turbo to fail to begin with. And has progressively been getting worse the last several months.

Interested to see what turns up in the teardown.

Originally Posted by louieXIII side note, i talked to one of my neighbors yesterday and he said he had a 2010 cx-7 and it burned out 2 turbos before they traded it in. i'm wondering if it's typical for cx-7s to just have horrible motors or if this is just a coincidental string of bad luck.

Probably the horribly designed PCV creating oil separation issues and high crankcase pressure. Hence why I suspect gunked up rings. Keep us posted.

[louieXIII]

i didn't do a leak down. i ended up just renting a compression test kit from O'Reilly, not harbor freight. i had no serious consumption before the turbo was replaced and now it's gotten terrible. so the engine is torn down. pulling piston rings and they honestly don't look that bad. does anyone know the torque value for these rod end bearings? or where i can find it? soon as i get these rings swapped i can start putting everything back together. it's been a long couple weekends.

[mazdaspeedchris]

So you have the motor apart and your only doing rings??????? You need to check for out-of-round and taper in the cylinders. If they are within tolerance for the motor then you can use the rings you bought and original pistons. If not then you will need to bore the block and buy new pistons and rings. If everything is good then you just need to hone the cylinders but make sure you do that or the rings won't seat properly. Also check the wrist pins. You should also replace all the bearings and have the crank checked and polished. Don't forget the assembly lube.

Really want to know how this turns out.

[Design]

I'm very interested as well. Any pooling or excessive carb deposits on the cylinder heads? How do the oil passages on the bottom rings look? Mostly open or gunked up? Any evidence of oil deposits on the plugs?

The only other thing I can think to check is the exhaust side of the turbo for wetness. It's possible (but unlikely) you got a bum replacement with bad seals.

[Vansquish]

Originally Posted by louieXIII yeah i already dropped 250 on rings, gaskets and a new vvt actuator to get rid of that cold start rattle sound. i was gonna go get another compression test but after reading that thread Mandinca's oil consumption problem i just said screw it. parts are all supposed to be here friday. getting a cherry picker saturday. gonna be a long weekend. you guys ever take apart the timing chain?

If you're doing the VVT actuator, you have to do a lot more than that. You need to replace (you cannot reuse) the friction washers involved in the VVT swap procedure.

[louieXIII]

October 6th update. cars running! tear down and rebuild was a pain in the ass. The Mazda factory publications stop at a certain point which implies removing the engine. just want you guys to know, once you pull motor mounts, you don't automatically have all the clearance front and back to pull the motor! i cracked my radiator filler neck in the process and some of the facia front and back of the engine compartment.

finally done with the build up and now i'm getting an odd symptom. oil consumption is no longer an issue. drives strong as hell. but i got this a check engine light and the code is P-2187 (too much air, not enough fuel at idle). When the car is driving, it gradually increases rpm and lets say near 3k rpm, it drops and gives you the illusion or the feeling that it shifted, but it stays in the gear. once it rises again from 2.5 AZ to 3k, you see the gear pos. on the dash move from 2nd to 3rd, or 3rd, to 4th. i only feel it in those gears. nothing sounds or feels rough. i was talking to a buddy and he said that your bypass (or blow off) valve is supposed to hold pressure to a certain PSI. code p2187 also appears to be a bypass valve stuck open or closed. my question is, anyone with a turbo charged mazda have any experience with this specific code? other than that, I basically have a brand new car under the hood! feels great. F*ck who ever engineered the damn thing, but i have no regrets once i put my foot on the pedal.

[Design]

Keep an eye on the level... fresh oil can hide consumption for the first 500-1K. Interested to know it burns a bit as the oil thins.

Not familiar with the code.

[louieXIII]

Originally Posted by Design Keep an eye on the level... fresh oil can hide consumption for the first 500-1K. Interested to know it burns a bit as the oil thins. Not familiar with the code.

do you know of a way to test a blow off valve?