Hello all! I am having an issue with my 2000 Civic DX, 3 door. This is the d16y7 with an auto trans. About a month or so ago I replaced the following.
Timing belt
timing belt tensioner
water pump
all accessory belts
valve cover gasket
spark plug seals
oil pan gasket.

After about a week or so I noticed a significant drop in the amount of oil and had seen some oil in my coolant. So the head was removed and sent to a machine shop. The head was cleaned up, resurfaced, and painted. The valves were also cleaned up as well as had new valve seals installed. And a new head gasket was installed. On the first crank the car started and car runs great and sounds good after a valve adjustment. No check engine lights, nothing. All coolant lines are new as well as the IAC.
However, I have this oil leak that is driving me nuts. So when I first fired the car up after the head gasket replacement, I noticed after 10 minutes, that the car was leaking from the rear of the motor. It was dripping off of the fly wheel cover. I assumed that since the oil pan gasket was a felpro that it potentially have failed. With the car being a 2000 I ordered a aftermarket oil pan and an OEM gasket. I installed it using Hondabond and bam, it still leaks. I removed the oil pan, cleaned everything up again, added Hondabond and bam, it still leaks. Prior to all of this, the car did sit for about 6 months, with it maybe being driving 3 or 4 times during that period. At this point, I am thinking that the issue is not the oil pan gasket but rather the rear main seal.

My question is this, can a failed rear main leak significantly enough to where you have a drop of oil every 2-3 seconds? I ran the car with the fly wheel cover off and it looks like it is coming from the bottom of the carriage area of the oil pan by the flywheel but can it be oil coming out of the rear main and possibly making it look like its the oil pan?

I am not opposed to pulling the trans but I rather have another opinion with someone who has possibly had a similar issue or has any input. I need this car out of my garage lol.
Let me know what you guys think! Ill answer any questions you may have.

 

If you remove the flywheel cover, you should be able to see oil dripping down the back of the engine if it's a rear main seal. If it's the oil pan gasket, the drip will start there and the block will be dry.

Hondas have really poor oil pan seals, even from the factory. I have tried all the same remedies you tried without success (clean surfaces with gasket, silicone greased surfaces with gasket, RTV with gasket, etc. RTV without gasket seemed to work the best. Others may chime in with their ideas.

 

Ill have to double check. I would hate to have to replace the gasket again but thats a lot easier than pulling the transmission. Ill post back with photos.of what I find.

 

This is how everything is set as it is today.

 

Take off the flywheel cover and see if there is oil behind the flywheel. That’s where the rear main seal is. Just from what you described it does seem like the rear main seal.

 

And yes, the rear main can get to the point of a drip every few seconds. A brand new seal with groove in the crank shaft flipped the seal in and I poured oil out and luckily made it home before the engine was dry. I had a trail for several kilometers from the rear main. The fix was a repair sleeve and new seal.

 

I ran the car with out the flywheel cover to see but it is difficult to determine if it the oil is coming from the rear main or the oil pan gasket. The fly wheel is not getting covered in oil though thats what makes me think it is not the fly wheel but that does not mean that it is not just dripping down to a the oil pan making it look like it was gasket leak.

It is a factory rear main seal. I have removed the oil pan again and I did notice that the oil pan gasket near the rear of the motor didnt seat right. Which doesnt help to make a definitive decision on what to do. So what I am going to do is clean up the oil pan surface (already did the block), and make my own gasket using Loctite SuperFlex Red Temp RTV. Ill let it set for more than 24hours and see what happens. If the leak doesnt persist then Ill leave it alone, if it leaks again, then Ill pull the transmission. Reason why I want to go with this route first (besides the obvious reason of not wanting to pull the transmission lol) is that a good friend of mine just dropped his 2000 Accord oil pan, and just made a gasket out of The Right Stuff and its been weeks and it hasnt leaked.

 

You maybe missing the details being provided to you. The rear main seal sits just above the oil pan gasket in that area.

You have to clean up ABOVE the gasket on the block, then run it and see if there is wet oil just above the oil pan gasket in that area. You can't see the spot with the inspection plate in place.



See how close the bottom of the rear main is to the oil pan. Now tell me, which is leaking? You can't until you clean it and see where the fresh "wet" oil mark comes from. Also, the oil almost never gets on the flywheel as it usually just drools down onto the top of the oil pan gasket right there.

 

I am listening to every ones advice. Like I stated earlier, the fly wheel inspection plate has been removed. I ran the car with the plate missing watching it from below but like you did state, its hard to tell the difference. This is what I am going to do, I am going to replace the gasket one more time, and if oil continues to leak, Ill have to pull the transmission. I will be doing this within the next few days so I will let you all know how it goes. Thanks again for helping out!

 

You said that RTV with out the gasket seemed to work the best. Did you this on the same car, a Honda Civic of the same generation with the same motor? If it worked for you, I probably will try that over trying it again with an oil pan gasket. Either way if it leaks, I am pulling the trans.

 

It's been awhile, I'm guessing even with something like a paint stir stick you are unable to get a rag in behind the flywheel to do a little cleaning?

The hope was to save you from replacing a gasket before you know if it is indeed the pan gasket. Trying to save you double or triple the work.

 

Yeah, its to tight to get anything behind the flywheel. I can upload pictures later on today. I do appreciate you trying to look out. Believe me, I do not want to keep doing this lol. However, I did order a FELPRO gasket that is very different from the original one I used and the OEM one I used. This is much thicker and more rigid.
https://drivcat.com/overlays/part-de...20Gasket%20Set



This is what it looks like, if you go to the link and look at the pictures, it actually seems in the photos that the application is the same motor that I have. Ill keep you guys posted on how this works. Ill be uploading photos later on today.

 

That felpro gasket is going to leak.

Better off using just hondabond and gluing the pan on.

 

I didn't have issue with the felpro but I also torqued the bolts and nuts to 7 ft-lbs with my low torque beam wrench. 1 mKg I think it was.

This wrench is like what I have but mine is 3/8 both sides of the head. I use it for low torque applications since my old inch pound clicker is waaaay out of wack.


I was going to try and put the metal rings in at the stud locations like the OEM gasket but the holes were smaller, so I just used the right stuff black in the corners like you do OEM and it's been fine.

 

I know some people have had a bad time with FELPRO. The first time I did the oil pan gasket, I did it with a felpro gasket, but the one I just used is a whole different part number, much thicker and stiffer so lets see.

I went ahead and put that gasket on today. Torqued it to spec. Had to go to work so Ill fill the car with oil up tomorrow and fire it up and see what happens. If it continues to leak Im going to leave the pan the way it is and remove the trans.

 

@TomCat39 I know you had said you couldnt remember what it looked like so I snapped some photos while I was underneath today.




The above photos show what it looks like with the felpro gasket on. It came with these plastic studs that thread into the block so that the gasket can snap into place and stay there while you put the pan on. Then you can snap the pan on as well and it will hold it up. I put some RTV in the required spots and installed the pan today. Ill keep you all posted.

 

Based on those last pictures, I don’t think it’s the rear main seal. I don’t see any oil on the back of the flywheel. When you took off the flywheel cover it would have had oil around there but it looks dry.

 

That's an automatic with a flex plate. You won't be able to see or get behind the torque converter. You also won't be able to see where the oild has run down the bell housing.

 

I thought it looked a little different but now I understand what you mean.

 

I only know because my wife's 93 is an automatic and I've motor swapped it a few times now. Learned the hard way there is a difference in the 6 crank mounting bolts on the flex plate versus a flywheel. The flex plate has shorter bolts than the flywheel by quite a few mm.

 

I was out of town so I was not able to reply with info. I gave the rtv 24 hours to cure and then ran the car. It did exactly what it was doing before. After about 3-5 minutes of running, it starting to leak. Just as frequent as before so now I am definitely convinced that it is the rear main seal. Ill probably start to take it apart next week or so. @TomCat39 You were right. Lets see how this goes!

 

Hello all.
I have been pretty busy so I have not had time to remove the transmission but I had time yesterday so I dropped it. I can now replace the rear main.

My question is, should I remove the cover that the seal is placed it and reapply RTV to the cover? I am asking since I already have gone this far to drop the transmission if it would be a good idea? Maybe some of the leak is coming from the cover?
I am referring to number 6 in the print.



Here are a couple of photos of what the engine bay looks like right now.

 

Hello all. Been super busy with life that I havent had a chance to update this post. New rear main is installed and so is everything else needed to get this car running. Ran it to operating temp and not a single oil leak anyone. Pretty exciting news! I will continue to update once the car is 100% road worthy with photos.

 

Good job, relooking over the photo's it looked like there was a bit of residue on the flex plate so was going to say I'm confident it's the rear main but it was determined by doing the work to fix it in the first place. Good deal.

Sorry I didn't get back to you regarding removing the seal housing and re-rtv'ing it. That is up to personal preference. I had my motor fully ripped apart and was doing the repair sleave etc so both that housing and the oil pump were off and resealed etc. I think it's good practice if it hasn't been done recently or ever.

Good job and thanks for sharing your success.

 

I appreciate you getting back to me. I did RTV the rear main seal housing just because when I took it off, it seemed that it had factory RTV. Im just happy the car isnt leaking oil any more. The rack and pinion is leaking but that will have to keep leaking lol. Next thing to do is a proper coolant flush and do a valve adjustment and the car should run great!