[evanwilliams]

Hey all, longtime lurker first-time poster. Great site and community here!

1999 Honda Odyssey with 167k miles.

I'm in the middle of changing my timing belt as I've been getting a rattle/ticking sound when it's cold out and it's definitely coming from the inside the timing belt cover, and reading around here I diagnosed it as a failing hydraulic belt tensioner. Which is what it looks like after I got the cover off (yay, I think I was right!).

But here is where it gets interesting, when I jacked up the Ody to start the work on the timing belt I noticed oil on the bottom of the pan which has never been there before. I do all my own maintenance and changed the oil 3k miles ago and there were no leaks at that time, so I assume it has something to do with the cold causing a seal to start weeping. It was dripping down the passenger side of the pan from the timing belt area so when I first started the work I assumed it was the crank seal and I would change it along with the other parts (easy), but now that I have the timing belt cover off I see the oil comes from above the crank, kind of in front (towards the bumper) of the water pump and works its way down through the lower timing belt area. After reading around here and other places I now think it's the oil pump gasket or something related to the oil pump as that's pretty much the only source of oil leaks above the crank apparently.

Questions: Should I be able to change the gasket and reuse the pump and all other related parts or should I replace the whole oil pump assembly? What parts should I change so I don't have to worry about this coming back after I button it all up?

Here's a link with the oil pump assembly diagram: OIL PUMP - OIL STRAINER Honda OEM Parts -- 1999 HONDA ODYSSEY for 5DR EX - Automatic

I'm also attaching pictures of my leak behind the timing belt cover.

Thanks,
-EW

 

[gregersonke]

It's far more work to replace than you think to replace the oil pump. Not to mention Oil pumps very rarely if never fail on stock configuration engines and are designed to last beyond the life of the engine. The only way I'd consider it is if you had hit some sort of debris that bent or penetrated the oil pan and bent the pickup. If you can just replace the seal I'd go that route.

 

[evanwilliams]

Thanks for the reply and the warning about the work. It looks like a bear and I'm still on the fence as to whether I should worry about it or just do the TB work and water pump and deal with the new oil leak until the van dies. But I am worried that the oil leaking into the timing belt cover could ruin the new TB I'm putting in. I also figured that if I'm going to do it in the future then I might as well do it now when I'm in this deep instead of doing all the rework to get here.

Can I change the seal without pulling the pump? From my Haynes (I know not the best book) manual and the diagram I linked to above it looks like the whole pump assembly has to be removed to change any seals. What seal or part number should I be looking at?

Any suggestions are much appreciated.

 

[evanwilliams]

I've come to the conclusion that the o-ring between the block and the pump is responsible for the oil leak as I see some oil seeping from the upper front area of the pump behind where the serpentine belt tensioner bolts to the pump (which appears to be near the oil in/out o-ring by looking at the diagram I linked to above, part #2).

Here is another good link with different pictures of the oil pump assembly plus instructions on removing the oil pump (for 2008 Ody, which looks the same as 1999)
howto: How to replace Oil Pump on 2008 Honda Odyssey?

I think the double o-ring is leaking and the oil is following the 2 bolts that go through the center of the pump and comes out behind the timing belt cover (the oil-covered bolt heads can be seen in my pics above).

Now the question is should I worry about fixing it (work) or just top off the oil regularly for the rest of the life of the van? The old TB doesn't actually have any oil on it as it looks like the oil clings to the engine pretty well as it creeps to the bottom of the pan. But it would be a bummer to lose a new TB due to oil contamination if the leak gets worse........

 

[New Dad New Van]

Here is some info on the oil pump for you if needed...

 

[evanwilliams]

Thanks New Dad! Those pages help a lot. I've decided to not pull the pump now as the exhaust/oil pan/pump removal will take more time than I have available to be without these wheels. In all honesty I bought the van 2+ years ago at 147k miles and hoped to make it to 200k without a major failure, and I don't think this leak (from what it looks like now and from what other posts on this forum have said) will be too much trouble over the next 3 years. It's hard to get too excited about doing all the work because I don't actually know how much oil leaks as I just noticed it when I was jacking up the car. Maybe once it get it all buttoned up and see what the actual leak is like I'll be more willing to tackle this job if it's bad enough. One thing I was wondering is if there is anything I can try without removing the oil pump assembly to stop/slow the leak? I was going to retorque all the pump bolts but I was also thinking about removing the oiliest ones and putting some thread sealant on them in hopes that maybe I have just a couple weeping bolt holes and it's not the o-ring after all.Thanks again for the replies.

 

[Crafty_1]

I had similar oil leak on my'02, right after I changed spark plugs. Long story short the new plugs seemed to exploit the bad PCV valve. Replaced PCV valve OIL LEAK STOPPED!

Apparently without proper venting the oil pan pressurizes and blows out oil pan gasket

 

[oldskewel]

I had similar oil leak on my'02, right after I changed spark plugs. Long story short the new plugs seemed to exploit the bad PCV valve. Replaced PCV valve OIL LEAK STOPPED!

Apparently without proper venting the oil pan pressurizes and blows out oil pan gasket

Thanks for posting the data point.

I've heard this sort of story (PCV Valve) many times, it makes sense, and it is usually a cheap and easy repair, so I generally consider replacing the PCV valve as one of the first steps in troubleshooting an engine oil leak.

Anyone else think this way?

 

[02ody02]

Interesting. I have had my 02 Ody in twice for warranty work lately and both times they told me I needed to fix the oil pump leak for $1,000+. The second time I had the mechanic show me the very small seepage, and asked him about whether it was worth fixing. He said he would not - that there is no catastrophic failure that could happen driving down the road, and he had never seen one leak enough that a quart was needed between oil changes. I will get my independent's opinion next time I take it in.

 

[HerbS]

As a follow up and confirmation, I've noticed oil on my driveway so I removed the TB cover and took a look. Not too bad inside, just an oil dab on top mounting screw. However plenty of oil below crank on top of pan and below and behind filter housing. Concluded that the oil pump to engine seal is bad. Based on above info I checked the PCV and it was clogged. I will also change the PCV and hope the oil leak is less. With 240k on the engine and the work involved I'll take a chance the leak doesn't get worse.

 

[RSpi]

I read this thread and thought my friend had this same leak. When I dug into it, I realized that the seal between the motor and oil pump housing had a crack in it so I replaced it and fixed the leak. A big relief. The oil filter housing is held on by 3 bolts and none of the timing stuff has to come off to do the job. Literally a 30 minute job and $14 seal.

 

[0dyfamily]

RSpi, thanks for the post and pic. Another great piece of very, very useful info to add to this thread...and it's only your 4th post!

You are the man.

OF

 

[02ody02]

RSpi, that is a not uncommon leak. I had it done by my independent at 117k miles, 7.5 years. A little over $100. Now I would probably look at doing it myself.

 

[Naim]

I am changing my TB now..
Managed to pull the lower TB cover off enough to see something similar before it got to dark and I was forced to call it a day.

I had a real bad oil leak and was just hoping that it was the oil filter housing gasket that needed to be replaced. I am sure that needs to be replaced as well, I will see tomorrow (weather permitting) how bad the oil is behind the TB cover.
Hopefully the oil filter gasket is then main source. Don't know if I want to get into pulling the oil pump assembly off.

 

[HerbS]

As a follow up to my entry earlier this year, the PCV replacement did not fix the leak as I had hoped. During the summer I removed the oil pump and found the gasket was brittle and cracked in a few spots probably upon removal. Not the easiest job, and upsetting since I had replaced the TB recently, but it took care of the problem. Can't complain as the engine is now over 10 years old with 250k miles.

 

[sontakke]

If you are already doing the timing job, how much more work is involved in replacing that gasket?

 

[Naim]

Thanks HerbS for the follow up on what happened with your project...
How much of job was it to replace the oil pump seal considering am I at the point of removing the timing belt now?
Do you replace the crank seal?

Any advance?

 

[vti]

How much of job was it to replace the oil pump seal considering am I at the point of removing the timing belt now?
Do you replace the crank seal?

You'll need to drop the exhaust pipe, remove the oil pan, remove the oil strainer (and the filter housing of course). Then you can detach the oil pump.
You'll need to reseal the pump and the oil pan with Hondabond HT silicon when installing them back.

For me it took 3x times of that for the timing belt job itself. And I also had to wait several days until silicon hardened (probably unnecessary but better be safe that sorry ).

And yes, I'd replace all the seals for cams and for the crank.


PS: I definitely wouldn't be messing up with the pump if it's not leaking

 

[eaglemtn]

2002 Ody

I had an oil leak in this area and had the dealer investigate it about 3 years ago when I had some recall work performed. They eventually decided that the leak was coming from the oil pump and gave an $800 estimate to repair the oil leak. They explained they have to essentially remove the items that are involved in a timing belt change to get to the oil pump - hence the high labor costs with this job.

I decided to just leave it alone and possibly have it done when the timing belt was changed in the future (if I still had the car). During the past 3 years, the oil would go down about a quart between oil changes. In the past few months I've had to add a quart in between oil changes. Of course, there's cardboard underneath the car in the garage since it leaks after being parked in the garage.

I decided to have the dealer do the timing belt change this past week and had them check the oil leak situation. After having the timing belt off and being able to look at the situation, they confirmed that the oil leak is around the oil pump. They replaced the seal (sealant I think) between the oil pump and engine, replaced the sealant on the oil pan cover, and changed the seal (not sure if it's a gasket or sealant) associated with the oil filter connector. This appears to have solved the oil leak problem (only one day of driving so far). They charged $200 extra for the oil leak fix ($150 labor). If the leak is fixed, I'll be happy not to have to worry about parking on my friend's driveways when visiting their homes. The technician indicated there was no oil leaking at the camshaft or crankshaft seals.

Too bad the car isn't like my friend's 2001 Ody which has never had an oil leak after 280K miles.

 

[vti]

and changed the seal (not sure if it's a gasket or sealant) associated with the oil filter connector

It's a regular rubber gasket with a metal screen in one section of it.