05 LX SE - puzzling oil pan leak - solved
 

Should probably begin with a thank you for the many times I have been helped by this forum. With the knowledge here, our 05 Civic LX 5 speed manual has done well. At 162k miles, it has a new timing belt, front main seal, camshaft seal, oil pump o-ring, and water pump. It also has a new input shaft bearing, complete with rear main seal, clutch, pressure plate, flywheel, axle seals, replaced engine mount, and some random suspension pieces. The cylinder head plug has been replaced, solving that leak too. Much of the support to take these projects on has been from here...THANK YOU!

The oil pan was removed for both the ISB (rear main seal) and the oil pump o-ring. A new pan gasket was installed each time. The first one during the ISB work was an aftermarket (Fel Pro?) from O'Reilly Auto. It leaked...so an OEM Honda gasket was used during the oil pump o-ring work, along with the timing belt and front seals. It too is now leaking. :( Oil appears to pool at two pan bolts (not the studs) on the side of the pan nearest the radiator. It runs and collects on the bolt directly above the exhaust pipe, then drips on the exhaust creating the wonderful oil burning smell. Everything else is DRY. No VTEC on this motor. The valve cover gasket and cylinder head plug are not leaking. Both front and rear seal areas are clean and dry, along with the oil pump o-ring area.

Work was done as laid out in the dealer service manual. The pan and block mating surfaces were both cleaned and dried to be spotless. Any old metal washers from the prior gaskets were removed and tossed. Hondabond was used at the engine block mating points and the corners of the curved sections. No leaks appear to be present at either end of the crankshaft seals or where Hondabond is used. The pan bolts were torqued to 8.7 ft-lbs/104 in-lbs using a 1/4" torque wrench, in a clockwise manner (understand a criss-cross pattern is often advised - I was following the Honda service manual, page 7-25), taking about 3-4 complete rounds before fully torqued.

What gives? Is the oil pan warped? What else could cause the oil to leak at these pan bolts? Using synthetic blend 5W-20 high mileage oil. Pondering if the additives in it may be causing the oil pan gasket to swell and leak (my father says "no way" but I remain skeptical).

Open to suggestions and feedback. Thank you for any help!

Re: 05 LX SE - puzzling oil pan leak
 

Pan could be a little warped, have you tried snugging the bolts a little tighter?

Re: 05 LX SE - puzzling oil pan leak
 

Not yet, but one of the options on the list for this weekend. How tight would you go? 10 ft-lbs? Reading various forum posts it seems like over-torquing can lead to this issue (warped pan/leaks). Considering removing the two offending bolts and adding some Hondabond to them as well.

Oil pan prices up around $110-115. Add in a new gasket replacement rounds out to ~$155. Not horrible, but not cheap either. Prefer to seal this one up if possible.

Appreciate your input! :)

Re: 05 LX SE - puzzling oil pan leak
 

10 shouldn't be a problem, even 15 is probably fine.

​​​​​That's certainly an option

I would try straightening your pan before getting a new one, junkyard is also an option, probably only like $20-30

Re: 05 LX SE - puzzling oil pan leak
 

Hmmm, ok. Nothing to lose at this point unless I snap a bolt. Will try this first, then remove and add Hondabond if the leak persists.

Not a big fan of having a junkyard pull a pan based on past experiences. I have found various aftermarket options for this pan which run $35-50, through either Amazon or eBay. Might go that route if not buying OEM. Pondering how I would straighten if I could figure out where it is warped...? I may make it worse, lol.

Thanks again :_beer:

Re: 05 LX SE - puzzling oil pan leak
 

Rubber mallet and the floor

Re: 05 LX SE - puzzling oil pan leak
 

Our son drove it a few miles last night. An inspection under the pan this morning was encouraging. The prior drop was spreading along the pan's metal reinforcement strip. No new drops formed on the bolts. I dried it off and decided to take out bolt where it originated. Added a small amount of Hondabond and torqued it to 105 in-lbs.

Only 25-30 miles since the front side seal and timing work was finished. No drops have hit the exhaust yet since this round was completed. Maybe I'm being anal and overreacting to a non-issue. Will watch it over the coming days and see if it stays dry or shows more signs of a leak.

Rubber mallet suggestion saved for the future if the leak recurs or worsens. :)

Re: 05 LX SE - puzzling oil pan leak
 

Caught a whiff of the oil burning today...***sigh***...sure enough, oil pooling on the bolts. The bolt with Hondabond (#1, counting from the left of the photo) was dry. The middle two bolts (#2 & 4) were wet, while the center nut (#3) also looked dry. #4 sets right above the exhaust pipe. I pulled out bolts 2, 4, and 5, cleaned them along with the pan edge. The bottom of each bolt was coated with Hondabond and reinstalled to 105 in-lbs. The threads on bolts 2 & 4 were very wet with oil - so strange with a brand new OEM gasket!
https://cimg5.ibsrv.net/gimg/www.civ...5f145771bc.jpg
https://cimg3.ibsrv.net/gimg/www.civ...b8aea5ea37.jpg

Re: 05 LX SE - puzzling oil pan leak
 

Those gaskets sure seem like a pain. I guess I lucked out with the D17a2 RTV only pan.

Not sure if you can throw out the gasket and just use RTV. Or maybe swap to the D17a2 oil pan that only uses RTV (this would also require the engine/trans braces).

Re: 05 LX SE - puzzling oil pan leak
 

Just checking.... there are little spacers embedded in the oil pan gasket. When you pull the pan off some of these spacers stay on the studs. Are you sure you removed any of these spacers that may have remained on the studs?

Re: 05 LX SE - puzzling oil pan leak
 

100% certain I got all of those spacers from prior gaskets off from both studs (where the spacer most often stick and stay behind) and the bolts (not usually found here, but can occur on the block or the pan). The leaks occurred on the bolts where there are only holes in the motor side. None of the studs are leaking.

I crawled under the car today with my light and took a look to see what this week brings. Knock on wood, it was still perfectly dry! The Hondabond seems to be doing the trick for those 4 bolts. Pondering if the reinforcement bar on the pan is not mating well with the bolts - could be bent or deformed from prior over-tightening. A new pan would solve this since it is part of the pan. If it stays dry, I will leave it alone and call it done for now.

Thank you again for the input! :)

Re: 05 LX SE - puzzling oil pan leak
 

I am finally feeling more confident about this. Zero signs of oil since adding the Hondabond to the bolts. Marking this one as closed. Knock on wood that I won't need to remove the oil pan again.

This Civic will likely go to our daughter as a college car in the next couple of years. It is reliable, safe, no longer leaks oil, and still gets 30-40 mpg. So funny to look back - she hated learning to drive a manual the first 2-3 months. Now she really wants this car to be hers, lol. Ordered a couple of bulbs today to replace in the cruise control switch. That will finish off the fix-it list, at least for now.

Can't thank this forum enough. In addition to the many things listed in the original post, it also helped us quickly track down and repair the broken wires for the rear driver's side power window.

Re: 05 LX SE - puzzling oil pan leak
 

Six-month mark since using Hondabond on those four select front oil pan bolts. Approaching 167k miles and the garage floor is clean and dry, ;) Hoping to get well past the 200k mile mark with this car.