What would cause a timing chain cover plate to leak oil on a 2006 Honda Civic? (Several spots of oil are collecting under the car daily). Took the car to the Honda dealership and they charged $105 to diagnose the oil leak by removing the lower pulley and stated it would cost $700 to repair. What would cause this with about about 70,000 miles on a Civic that has been maintained and serviced regularly? Is this a common problem for this make/model? An independent mechanic looked at the car at no charge and thought the leak could be from the crank seal.

Thoughts:

Not a common problem at all. Usually, you never really know why seals fail. Stuff just happens. It could be due to a manufacturing defect in the seal, improper installation, nick during installation, or over filling the engine oil. Seals can become brittle and leak over time. Encrusted, oxidized oil also contributes to oil seals leaking--hence, the creation of high mileage oils. Outside of trying a high mileage oil, or 5W-30 weight oil instead of 5W-20, replacement is the only viable option. Consider trying Valvoline MaxLife Synthetic 5W-30 oil next time.

It's also possible the leak isn't coming from the crankshaft seal at all. Many mechanics do not use Honda Bond at key locations on the valve cover seal. This can lead to the valve cover leaking. Because of gravity, leaks often originate far above where you suspect they are coming from. Therefore, I would start with retorquing the valve cover to 84 lb.-in. after applying Honda Bond in the corners of the gasket near the camshaft.

Here is an update on my situation... Had the seals of the timing chain cover plate replaced by an independent mechanic for parts and labor cost of $514 vs the dealership estimate of $700. Oil continuities to leak and now a clank/rattle sound started coming from the engine. Took Civic back to independent mechanic and he replaced a pulley (charged $96 for the part only which did fix the "sound")and then he put a second set of new seals in the timing chain cover plate and meticulously cleaned all the areas where the oil had leaked. However, it is still leaking oil?! I am taking car back to independent mechanic today to investigate further. I am very hesitant to have Honda dealership look into this as it seems that this is where it all began... Originally took Civic into dealership for a basic oil change and then the vehicle began leaking oil. Hesitant to take the vehicle back to the dealership, took it to independent mechanic where he discovered the dealership had failed to replace the washer with the bolt on the oil pan. New oil was drained and replaced and washer was installed. Thought this would fix the leak and it did not. Independent mechanic thought the Civic may have a crank seal issue, but recommended having dealership look at it as he thought it may be a Honda recall issue. Dealership charged $105 to diagnose leak and said it was the timing chain cover plate and stated it was not due to a Honda recall issue. The time chain cover plate seal is obviously not the issue... seals have now been replaced TWICE along with installing a new pulley. Cost starting with a simple oil change has now soared to over $800 and the car is still leaking oil. Do you have any additional thoughts/advice? Also note that I use synthetic oil (Mobile One) and have been religious about oil changes. Could this leak problem be due to the dealership "over filling" the oil when it was changed?

What Civic model and engine do you have?

2006 Honda Civic EX (4 cylinder)

I don't have any personal experience working on a Civic with a timing chain. I know some people are against Honda using a chain on these engines, contending it sets up small vibrations that cumulatively cause internal parts to loosen and leak. I just don't know if this is really true or not. Personally, I would take it to Honda/Acura for servicing. They know this engine best. Talk to the service manager, explain your problem, and ask for their best tech to do the work. I don't think you really have a better option.

Try putting 1 bottle of marvels mystery oil in the engine, you may have a hairline crack in the engine block it's self

Oil leak update of 2006 Honda Civic: Decided to seek a second Honda Dealership to diagnose oil leak... The first Honda Dealership charged an hour of labor to diagnose the leak (said it was leaking oil from the timing chain cover plate). I took the car to my independent mechanic to do the work but it DID NOT fix the leak; first Honda Dealership mis-diagnosed the leak! Took Civic to another Honda Dealership that finally found and fixed the oil leak! They discovered that the sealing bolt behind the water pump pulley and tensioner was leaking oil. They removed and replaced water pump pulley and belt tensioner; removed sealing bolt and resealed. It cost $123 bucks for diagnosis and repair. Sad to say that after paying several hundred bucks to three different mechanics (two dealerships and one independent)the car no longer leaks oil.