Cleft_Asunder

iTrader: (1)

I am trying to diagnose why my car is burning so much oil and why it has very low power. Details:

NGK platinum plugs.
Cylinder 4 plug has oil on the threads, but no leak from plug seal and no oil on the electrode.
All 4 electrodes look the same with same carbon fouling. (they look okay)
Burns a lot of oil.
Engine runs smooth but lacks power and just doesn't want to accelerate quickly. Seems to get worse when it's hot.
35 psi fuel pressure test.
Cat has 3k on it.
Fuel filter, wires, distributor cap and rotor have low miles on them.
167k miles.

After doing some research, I'm suspecting the head gasket or maybe oil ring/rings. I'm going to do a compression test tomorrow...

ezone

Pics?

How much? How many miles per quart?
Probably unrelated to oil consumption.
Address as a separate problem?
Smoke noticeable or no?
What happened to the previous cat?

Usually excessive consumption is caused by stuck oil rings.
You can't find that with a compression test.

Wankenstein

Read https://www.amsoil.com/techservicesb...onsumption.pdf

My son's '07 Mazda 3 (2.3L) suffered from high oil consumption that eventually lead to rod knock. The engine did not have any oil leaks and ran smooth. Minimal smoke from exhaust that smelled more like fuel (rich condition). It would consume about three quarts in two weeks. We concluded that the most likely scenario was that described in #3 of the link I posted.

However, not time to hit the panic button yet in your case. Answer Ezone's questions first. Also, which year and model? Stock engine? Engine model (ex: D16Y8)?

Cleft_Asunder

iTrader: (1)

I apologize you two, but I am very busy right now and I will follow up on this when I have time. Thanks for your suggestions so far. Once I do a compression test (even if it is useless or not) I will reply.

Wankenstein

Apology not accepted! Kamikaze pilots died for what they believed in on a day's notice and you can't even muster-up a compresson test in two weeks..LOL. Just kidding of course, I have some post from a month or more ago that I still haven't followed up on. But it's not my fault, the video below shows the reasons why:

Cleft_Asunder

iTrader: (1)

Hahahaha, brilliant! Ya bastard. ^_^

Cleft_Asunder

iTrader: (1)

Okay so... using the autozone "OEM" gauge, I got these numbers. Maybe the gauge isn't that accurate, I don't know.

1: 150
2: 150
3: 149
4: 152

Let's just forget about the 4th plug right now and tackle the lack of power. Frankly, I'm out of ideas. -_- I've been running injector cleaners through it and even heet water remover, but no difference.

Air filter is fine BTW.

TS2008

Timing check ?

ezone

At least they are all even.



If I used my equipment and my methods, those numbers would be quite low.
Cam timing check?

Wankenstein

1) Did you do the compression test with the engine cold, warm or at operating temp?
2) Were all the plugs pulled when testing each cylinder individually?
3) Wide Open Throttle for each cylinder
4) Distributor harness disconnected?
5) Battery fully charged and optimal cranking?
6) Do a dry and wet (with a tablespoon or two of oil) test?
7) Between 6 and 10 full crank revolutions (roughly 6 to 10 seconds)

ezone

I don't do this.

I put the gauge where I can see it.....I crank it and keep on cranking until the gauge quits climbing....and keep cranking it a few more 'hits' just to make sure it's maxxed out the gauge.

I also watch what the gauge does during each hit (amount of rise) and mentally compare this with the rest of the cylinders.

Wankenstein

I just helped my son do a compression test on his Mazda 3 a few days ago and performed it the way you just described. Unfortunately, we have to do it again as the battery was weak and did it while engine was cold. We're currently replacing his in-tank fuel pump (drop tank) and afterwards plan to re-test compression with fully charged battery and at operating temp.

Cleft_Asunder

iTrader: (1)

Yes for everything except for 6. I'm kinda curious about the battery, even though it's new, maybe the alternator isn't charging it properly, causing weak ignition. Or a timing issue...

Wankenstein

How much oil consumption per month?
Have you changed the PCV valve?

Cleft_Asunder

iTrader: (1)

This post is pending right now. My issue with the car is "take it to the mechanic" status. It runs, and smooth, but when the engine gets hot it feels like there is a bottleneck. In 4th gear, doing 60, I will accelerate and I can't get out of my own way fast enough. I feel like the issue is simple, but not simple enough to diagnose if you are not a mechanic. And no, my PVC is fine, thanks for the suggestion. But then again... how long does a PVC last? I replaced it at maybe 100k, and now I have 167k on it.

ezone

Exhaust restriction?
Intake restriction?

Cat code?

Wankenstein

manual says to replace every 12k miles so, it's 55k miles overdue..lol
Easy test is to remove it, shake it, and if it rattles it's still functioning and not gummed up. Much easier to replace during oil change when oil filter is removed.

ezone

IMO the PCV cannot cause this complaint.

OTOH, replace PCV valve every 12k sounds like serous overkill. Don't have time to check, but I bet it says to inspect, not replace. I'd expect replace every 60k or something similar.

Wankenstein

You're probably right about every 12k (4th oil change) being the inspection mark and not the replacement interval. During 12k inspection it could be sprayed out with brake cleaner help keep it clean/functioning. Autozone sells a decent aftermarket for $4. Here's a link for PCV info: https://axleaddict.com/auto-repair/H...PCV-valve-test As you said probably not the source for oil consumption but, would do the OP's engine good to inspect/replace it.

ezone

Oil consumption? I thought this was primarily about a low power complaint, with secondary issues like oil consumption...I kinda suspected a clogged cat from this part of the description. Heavy oil consumption could lead to a clogged cat, or a broken cat substrate could lead to exhaust restriction.

Cleft_Asunder

iTrader: (1)

So I removed the O2 sensor on top and the cat looks new. Sigh, I'm all out of ideas. I even swapped my injectors thinking that one was not putting out enough fuel for some reason, but that didn't work. I found a massive amount of oily dirt in all 4 intake manifold fuel injector holes. How the **** did that get there? It didn't go through the seals.

Wankenstein

Going back to your initial post.. what is the model of your car? Is it an automatic or manual transmission? how long have you owned it?

You stated the cat converter was replaced 3k miles ago. Is low power and oil consumption the reason you had it replaced?

Are you seeing any smoke from tail pipe on cold starts? Have some one start the engine while you check for exhaust smoke: black, blue or white, and take note of odor. Also, go for a drive and have someone follow you closely and observe your tail pipe for possible smoke. Do intervals of hard accelerations and decelerations. If it's not leaking oil and it is burning oil read this: http://atomium.eu/home/excessive-oil-consumption/
https://www.amsoil.com/techservicesb...onsumption.pdf

The compression test you performed shows that cylinder compression looks good but, does not rule out compression loss through (possibly) leaking valves.http://www.ssch.com.au/trade-news/a-...valve-failure/ Might want to get a leak-down test performed.

ezone

It's normal, I wouldn't worry about it. The injectors can't spray up that high to clean it off.

What about when cold?

Cleft_Asunder

iTrader: (1)

I'm paying attention to what you guys are saying, but I'm focused on my ignition system right now just to make sure it's working properly. I had a chinese ignition coil in there so I replaced it with a TEC. I also replaced the plugs with inexpensive stock NGK copper just to be sure. There really isn't a noticeable change after the full ignition tune-up, but I'm wondering if I should suspect the ignition control module? It's probably not that. Maybe the TPS...

ezone

Pre-edit: Elaborate on this, more details?
Engine temps, time after startup, etc?

Still running on the original O2 sensors?

Unplug the front O2 sensor and drive it, see if symptom disappears while the sensor is unplugged.
Sure the CEL will eventually come on, but see if the symptom goes away.

Cleft_Asunder

iTrader: (1)

Haha, you make me laugh ezone, because you're actually interested in solving random peoples problems. You're like me, you actually care. ^_^

I haven't unplugged the pre-cat 02 but when I do I will post back. On a cold start, I get 5 seconds of white smoke but that's normal water evaporation right? But what concerns me is the fuel smell from the tail pipe. I need to confirm that the fuel smell is consistent...

ezone

Sometimes I like a challenge.
Other times not so much LOL
My main job is solving problems.

The world is full of people who work on cars.
Far fewer actually fix them..... on purpose. That's where I come in.
How bout you gather up ALL the important details in a single post?

Maybe make a video showing the problem as it happens so we all can experience how you are driving and what the car does when it does whatever it does?

Steam, water, condensation from exhaust is normal. Steam dissipates quickly, does not hang in the air. Check other cars that have no problems to see what is normal.

Gas smell on cold startup might be ok depending on conditions. Once the cat gets heated up it should consume that smell.
Unless it is misfiring upon startup. A dead cylinder would pump its fuel right into the exhaust without burning.

What are you calling a gas smell anyway? Raw fuel from the gas station pump, or raw exhaust like from an old lawnmower???
If you already know you have a leaking exhaust manifold it may just be the raw exhaust leaking that you smell.

Cleft_Asunder

iTrader: (1)

Man I don't even know what to think anymore. The car has been running smoothly in all rpm ranges for a while now, but it accelerates really slow and has no power. (as in it can't pull its own weight)

I don't want to overcomplicate my description because I have done a tune-up, there is no check-engine light, and the cat looks good from the top. And I don't want to take it to Honda because I'm worried they will spend a great deal of time on diagnosing it and they will not be able to figure it out. (even though again, I think it's a simple problem, but maybe hard to find)

What was I supposed to expect with the pre-cat 02 unhooked? Any other simple ideas would be good...

ezone

Unplugging the sensor was intended to disable fuel adaptation, force the computer to supply fuel based solely on its lookup tables or fuel map (open loop) instead of allowing the O2 sensor to send feedback to the computer (closed loop) for fuel corrections.

I am familiar with complaints of "falls on its face when trying to pull out of the parking space" that are sometimes caused by the primary sensor getting 'stuck' at high or low voltage, which causes the computer to over or under calculate fuel delivery, but the sensor fault usually doesn't last long enough to set a fault code (in the early stage of failure). Disconnecting the sensor is one more thing I can do as a diagnostic step.


If I suspect the exhaust were plugged up for whatever reason, removing the primary sensor opens up an 18mm hole in the exhaust, pre-cat....so if the engine gains a little performance then I have a good idea if I'm on the right track.

Has the cam/crank timing (belt) been verified yet?