A lot of blow-by and exhaust smell in oil

ZEVITH

MEMBER
2001 HONDA CIVIC
1.7L
4 CYL
2WD
AUTOMATIC
220 MILES

Hi, I have the EX model. I got my head gasket redone from a shop a few months ago. I got my car back and then noticed it had a lot of blow-by it did not have before and the rpm’s would surge (drop and rise erratically) upon heavier acceleration the engine bogging down. It also lacked power, engine using oil, and engine oil smelling like exhaust. I asked other mechanics and got mostly that my timing was probably off. Well, I complained to shop that did the work and took my car back to them since the head gasket work was still under warranty there. They said they checked the timing and other other stuff. They then said it was worn piston rings, not my timing, etc. So, I had them replace them along with the rod and bearings. So now, I got my car back six or more weeks ago. I have noticed it has been using oil. Also, I still have a strong exhaust smell in my oil, along with the pretty strong blow-by feels and blows exactly as it did after the head gasket was done as mentioned earlier. When you remove the oil cap or oil dip stick, it will blow your hair up if you have long hair, or blow a piece of paper off and away from it, it is like a small fan blowing with puffs. The car runs better yes, but it just does not seem to have the power back either I expected it would. So is this normal, having the blow-by and all after all this supposedly work done on my vehicle? I am wondering if the rings were even changed out. I do know the guy at the shop told me they did not bore/hone the cylinder holes. I am not familiar really with that, but I asked it.

7 Replies

JACOBANDNICKOLAS

MECHANIC
108,192 POSTS

Hi and thanks for using 2CarPros. Com.

That much blow-by is not normal and indicates the compression rings are not doing their job. Now, that can be due to excessive cylinder wear, which should have been checked prior to replacing the rings, the rings were installed incorrectly, or simply because the cylinders were not (at least) honed. When the engine was new, the manufacturer honed the cylinders. Basically, tiny high and low spots are created in the cylinder. It is important because it helps the cylinder wall retain oil. Without it, the rings and cylinder walls will wear faster.

Now, from normal usage, a glaze is created on the cylinder. Basically, that is caused by the piston's movement within the cylinder, flattening the original imperfections created by honing prior to assembly. Without removing the glaze (by honing), the rings will not properly seat and will wear much faster.

So, with that being said, if the cylinders were not at least honed, the process was most likely not successful. It may have seemed a bit better at first since more compression was created, but that will go away fast.

I hope this is helpful. There is more to it than just honing the cylinders, however, that is a minimum requirement when replacing rings.

Let me know if you have other questions. And yes, the blow by is caused by bad compression rings (or worn cylinders which should have been checked prior to replacing rings) and the oil consumption and smell is because the oil rings are most likely worn or the cylinder was too big to start allowing oil to bypass and get burned in the combustion chamber.

Feel free to ask questions.

Take care,
Joe

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Tuesday, November 13th, 2018 AT 7:37 PM

ZEVITH

MEMBER
5 POSTS

I understand. I told the shop guy that (as far as I had researched) that it seemed the cylinders should be honed - that was before they did the ring job. So, how should I handle this you think? I am pretty upset about it, feel like I’m being severely screwed over again. They had my car for a very very long time and I went along with them having it for over a month or two, because I was very sick for a while during then. I got better and then kept having to push them to get to my car to get it fixed while it supposedly sat there at their shop. That same scenario also happened during when the head gasket was to be repaired by them. I had to use friends’ cars to get around - very inconvenient.

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Tuesday, November 13th, 2018 AT 7:57 PM

JACOBANDNICKOLAS

MECHANIC
108,192 POSTS

Welcome back:

I honestly I am not sure what to tell you. Was there any warranty on their work? If so, was it in writing? If they did not supply a warranty, you may be stuck.

I wish I had something better to say, but that is the way the law would view it.

Let me know,
Joe

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Wednesday, November 14th, 2018 AT 6:13 PM

ZEVITH

MEMBER
5 POSTS

As far as I know they carry a warranty, but I personally do not know what they might would throw at me as to justification, if any. I want to make sure I am prepared and armed with knowledge first. I do know I stressed repeatedly about them honing the cylinders (based off my research), but they told me a number of times it does not need honing. I wanted the job done right and stressed that to them before they took it on. Based on their statements of them doing a piston ring job on my vehicle, I was not supposed to have any of the blow-by anymore I had complained about previously, not any oil usage either. And they said the valve seals were good, did not need replacing. Everything is in writing. I just do not see their warranty on the receipt.

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Wednesday, November 14th, 2018 AT 7:37 PM

JACOBANDNICKOLAS

MECHANIC
108,192 POSTS

I would first contact them and before you express your concerns, kindly ask if any guarantee is offered when they work on a car. Once you get a response, explain what was done and the results. See if they are willing to help. Remember, you catch more flies with honey than you do vinegar. Lol

Let me know how things work out for you or if you have other questions.

Take care,
Joe