jeb147

Hey everyone,

I've been lurking on here a while, but have never run into an issue I can't fix with the help of the forum. Until now...

I have a 2004 Civic Si (Canada), with a manual transmission. It currently has 190,000 km.

I am currently losing oil at a rate of about 1.5 - 2L per 5,000 km oil change. I top it up about 5 times throughout the oil change period to make sure its full.


A bit of history:

I've owned the car since about 120,000 km, and have serviced it regularly myself. The only issue I had was about 4 years ago at about 140,000 km, which required a headgasket replacement. It ended up being a small tear in the gasket, which was pressurizing the coolant system. This work was done by a local shop in town.

Anyway, I checked the compression before and after the job and it was good across the board. I can't recall the values right now.

Fast forward a few years and the car still runs great, but I am losing oil. Hard to say when this started happening.

- There has never been a leak under the car
- Plugs are dry
- The car is driven 80% in the city and stays below 3,500 rpm for the most part
- On longer highway trips (1,000 km), the car burns next to no oil - weird...
- Not burning blue or white
- Oil seems to get dirty faster than any other car I've owned

I took a few pics today as I got the car ready for winter. The engine is a bit dirty after the first snowfall right now, but there is no signs of oil anywhere. EXCEPT just under the cam seal near the EGR. My theory right now is that oil is leaking out of the seal, staying in the pocket beneath the EGR, and burning off from engine heat.

Thoughts? Any other ideas? I haven't yet run a recent compression check, but I may give it a go.

I have attached a few pics.


Thanks for your help!

Jordan

ezone

Cam plug leaks, replace the plastic plug.
Next common leak up high is the VTEC solenoid gaskets, they are rubber and eventually harden and shrink leading to leakage, sometimes very rapid because full system oil pressure is behind the valve.

Oil consumption rate typically increases as an engine accumulates miles and age, that's pretty much expected of just about any engine eventually.
Usual cause is sticking oil control rings, stuck in their grooves due to carbon buildup.....which means pulling the head off and a pulling the pistons out to fix right and immediately.
I've advocated the use of higher quality oil to slowly help the rings without teardown, but it's not guaranteed.

Some people would rather buy a truckload of oil before paying the cost of a ring job.
If you can stay ahead of the oil consumption rate, do.
If it becomes too rapid and you can't keep it full, it may cost you an engine job....

mac25

You have three options:

-run it the way you are with the oil you're using and top it up.
-increase the oil film (additive), or, the viscosity (10w30)... or do both.
-rebuild the engine.

Colin42

I used to have to dump a quart of oil in after 4000kms (5w20 syn), switched to 0w20 syn (ezone had recommended this to another member in another thread) and checked at 4k, it was still full. Checked again at 5k and it was finally down a quart. Hopefully my oil consumption will continue to slowly improve, and since I was already using synthetic there was no cost increase.

jeb147

Thanks for the suggestions.

Wouldn't you expect to see obvious signs of oil burning on the spark plugs and exhaust?

Why wouldn't it burn as much on the highway (3500 rpm) if the rings were worn or sticking?

Im going to get another cam plug and vtec solenoid gasket and give that a try first.

Ive already switched from 5w20 to 5w30 with no noticeable improvement.

Jordan

ezone

Depends on the rate of consumption
Rare, because a working catalytic converter can hide quite a bit of smoke if it's burned slowly....plus most would never notice a little smoke behind them in the mirror, not unless it is a huge cloud.
Oil consumption can lead to premature cat failure too.


There may be many variables at play here.

Check if it is wet below the valve first.....and if it is, there are two separate gaskets you can replace.
Old school thinking is old. Changing flavors doesn't always work the way some people expect it to....especially when dealing with modern engines.

M.Stribling

I was losing a similar amount of oil over 3,000k miles and would have to top it up every once in awhile. I have a 04’ Civic 1.7L with now over 201k miles not km and recently I had my timing belt/water pump replaced and while they were doing the work I had them adjust the valves and replace the valve cover gasket. Ever since then it goes through a quart of oil every 5,000 miles on it which is much better. The plug by the EGR has yet to be replaced but it doesn’t seem to be leaking. I found replacing the valve cover gasket with a silicone one ended up bringing my oil consumption down significantly and to me burning 1Qrt per 5k miles on an engine with over 200k original miles is not bad. It’s something you can do yourself and I was going to but I figured since I was getting a new timing belt/water pump, I decided to have them adjust the valves and put in the new gasket and I was able to get it done for less than $900 US. Very pleased with the results and it gives me more peace of mind considering these are interference engines and if the belt breaks my engine will need to be rebuilt. The gasket and a tube of gasket seal is pretty cheap, maybe around $30 for the gasket kit and the Honda gasket seal. I bought the gasket kit off rock auto and have driven it close to 11k with the new gasket and am happy all things considered . If replacing the plug doesn’t help, maybe look into replacing the valve gasket and while it’s open maybe adjust them, you only need a 8mm wrench, screw driver and some feeler gauges to do it yourself.

long story short, replacing the gasket really helped me consume less oil. You will know if your gasket is seeping by if the engine is dirty/oily all around the engine below the gasket. I also put in some stuff called AT 205 resealer in the oil, it’s cheap and it helps rejuvenate other rubber seals like the one between the engine and transmission.

I plan on keeping the engine running as long as I can. Regardless what you do, just make sure you keep the oil level up and always change it between 5-8k miles depending on how many miles/km you have on the engine. You can also replace the PCV valve which I also changed myself as the old one was getting old and sticking open.

I also switched to full synthetic. It’s just the Napa Auto brand and I buy it on sale when it’s around $3 a quart. Can never have too much cheap oil, especially if it’s being burned up or seeping/leaking.

hope this helps

Wildcat445

I am not so lucky--I successfully did a cylinder head replacement and the engine runs smooth as butter with 248k miles on it. But after I did all this work, I noticed it was burning a LOT more oil--it needs topping off with every tankful of fuel.

Had I thought of it, I would have pulled the pistons to replace the rings, and honed the cylinders (as they were a bit shiny). I may need to tackle this later in the month (in our wet/cold/dark weather) since the car may be going on a road rally in late April. I did try one of those attempts to soak the cylinders with something like Seaform or Marvel Mystery Oil a couple months after I got it reassembled, but it did nothing, as expected. I have a feeling it's a combination of the rings and the cylinders losing their cross-hatching. There is no way of knowing how this car was maintained for the first 180k miles of its life.

I do have another oil leak again, but it may just be a valve cover gasket leak as it's at one corner of the engine near the front. But after the new cylinder head went on, it was dry for several months.

It is rare, but the head gasket might also cause leaking oil--Eric The Car Guy had a recent video about a leak on his son's '05 Civic and found a tiny nick in the block that was causing the oil to seep out. That could have been a case of careless previous work on the engine. Since I'll have the head off, I am going to check for this, just to be sure.

Wildcat445

Quick update on the '04 Civic--I pulled the head again, replaced the piston rings (the oil rings were stuck in the piston grooves), and honed the cylinders. It cleared up the oil burning immediately. I'm about 500 miles into it and the oil level hasn't changed at all. I went ahead and did a new valve cover gasket set, and had to use a Heli-Coil on one of the valve cover threads since it was stripped (this was a rebuilt head). Did a test run on nearby highways and got 40.1 MPG. I'd say it's fixed.