2001 QX4 oil leak - need help identifying the part

[suncoach]

I have a 2001 QX4 (2WD) with about 120K miles on it. I live in Orlando (hot and humid most of the year) Oil has been leaking on the ground from under the passenger side (for a while) and is getting worse. I removed the skid plate and took some pictures of the source before I cleaned it. (see below). After cleaning all of the oil and grease off, I was able to see the oil flow down from the top inside middle of the part in the picture when the truck is started/running. Stops flowing when turned off (but leaves a nice little stain on the ground). There does not appear to be any leaking comming from where this part connects to the block or from lines connected to the part.





My questions are:1. Does anyone know what part this is (to the right of the filter) oil cooler? oil cooler assembly? oil pump?2. What's broken/how is it best fixed (i.e. gaskets, seals, replace the whole part??)4. Where can I buy the part(s)?3. Instructions for how to fix it myself (if possible - it looks fairly straightforward to replace the whole part - not sure if it can be rebuilt)

Thanks in advance!
Modified by suncoach at 9:27 PM 10/25/2008

[jimbyjimb]

Not familiar with QX4 but it looks like a diaphragm or regulator of some kind. Could be a relocator for the oil filter? Consult a more experienced member or look at an FSM. The FSM is a sure bet. Could be a relief, a diverter, not sure.

[Q451990]

By the way, you can download your FSM at http://www.phatg20.net

I believe the mystery part is the "oil cooler" and you'll see how to remove and install it beginning on LC-7 in the FSM. There are a couple of o-rings that could be suspect.

Once you identify the parts you need, I would highly recommend Infiniti of Scottsdale a/k/a http://www.everythinginfiniti.com. I think they may be having a special this month? Might be worth calling them at 1-888-216-5328.

Welcome to NICO!

Heath

[suncoach]

Heath,

You're correct, it is the oil cooler and it looks like from the position of the leak in the FSM, it appears to be the o-ring.

Thanks a ton for you help and the links. Very helpful. Should be an easy fix.

Thanks again!!

[Q451990]

You're welcome! Please let us know how it turns out... and if you happen to take some pictures of the process, feel free to post them

Heath

[suncoach]

NO MORE LEAK! The culprit was the large o-ring in the oil cooler. A Simple do-it-yourself repair (with an oil change to boot since you need to drain the oil in order to replace the o-riings) in about an hour.

Picked up both o-rings from the local dealer - $15.48 for the small one and $21.42 for the large one. Even though the small one wasn't leaking, thought I'd replace it at the same time as the big one just to be safe.

Picked up some oil and and a new oil filter from the local auto parts store to save a few bucks.

First I drained the oil by removing the oil drain plug. Then I removed the old oil filter. In order to reduce the mess I used a neat trick from another post on this site - after loosening the oil filter, unscrew it the rest of the way using a gallon size plastic baggy to contain the otherwise big mess from oil pouring out of the full oil filter as you remove it.

Then it was time to replace the oil cooler o-rings.

Here is an exploded picture of the oil cooler and o-rings from the FSM (thanks again Heath!). I colored the o-rings yellow. The one and only bolt that I had to remove is the red one:

Here is the actual oil cooler again:

The red arrow in this picture points to the actual bolt I had to remove:

The space was really tight. Unfortunately the ratchet wrench was too big so the only way to get at it was with a 17mm open end wrench with very little room to move but it can be done.

There was a rubber hose in the way so I had to remove the bolt (see red arrow) in this picture in order to gently push the hose aside (an not break the pipe it is connected to) in order to get at the oil cooler and be able to actually turn the wrench:

Once I could get at the oil cooler bolt I (carefully) used a hammer to tap the wrench in order to loosen the bolt. From there it was easy, just a lot of little turns with the wrench finishing it by hand.

Here is the loose bolt:

Once the bolt was removed, I found the small o-ring embedded in a grove on the bolt itself. The large o-ring was inside the oil cooler. Here is a picture of the open oil cooler:

Here is a picture of the old o-rings:

I had to dig the old small o-ring out of the grove in the bolt. The new one fit in nicely, just a little slippery with all the oil but it finally fit flat.

Here is a picture of both large o-rings. The new one is on the left and the old one is on the right. Looking at the indentations in the old one, I can see why it was leaking!

Here is a picture of the new, large o-ring inserted inside the oil cooler before I put the bolt back in and closed it up:

I had to pay special attention to alignment when putting the oil cooler bolt back in - had to "eyeball it" and make adjustments since there was a little play when tightening the bolt.

From there it was just a matter of putting the oil plug back in, screwing on the new oil filter and bolting the skid plate back on. Oh yeah, and putting oil in.

Hope this helps if you find yourself with the same problem/leak.

Modified by suncoach at 12:25 AM 11/2/2008
Modified by suncoach at 11:00 AM 11/2/2008

[Q451990]

Wow... awesome write-up!

Heath

[Q45tech]

Iron clad proof of owner abuse in failure to change oil every 90 days and allowing oil to overheat and turn acidic degrading the o ring.

[suncoach]

Funny you should mention that. I was a fanatic about having the oil changed every 3K miles, even if it was at less than 90 days (which was often). Until I read that 3K was overkill and a waste of money and that every 5K-6K miles was fine. The leak had already started before I switched to 5K-6K intervals.

However, I did buy it previously enjoyed so perhaps the 1st owner was the "abuser".

A couple of questions though. By "degrading the o-ring" do you mean the indentations? The large o-ring looked to be in good shape except for the two impressions. Thought those were just a matter of normal wear and tear over time. How long should the o-rings last (in years/miles)?

[Chris92SE]

More searching and I come up with this great post (I also found one in the Pathy/QX4 section).

Excellent write up.

I have changed the oil every 3-4k miles at a dealership and my oil started leaking just a bit ago. I would usually do this type of repair myself, but it is 30ish degrees and my garage isn't heated, plus I am really busy.

Anyway, I found a Nissan specialty shop that will do it for $100, which is well worth it to me.

In talking to the guy on the phone, this is extremely common with the 2001+ pathy/Q. I think it's just one of those things that doesn't work out too well for owners of these vehicles, not necessarily poor maintenance.

[garyd333]

Hi "suncoach" (and anybody willing to chime in on this),

I just read your post from 11/1/08 regarding a repair that you made to your Oil Cooler. I have the same type of issue....but was told (by local service garage) that I need the entire oil cooler assembly replaced. Quote was for $450 to $500. (about 1/2 for parts...1/2 for labor)?

Anyway....the images you had in your step-by-step did not show up. I was curious if you still had them...and would be willing to share them with me? By the sounds of your write up, this sounds like it might be in the realm of "diy"?

Lastly, there was a link reference to download your FSM at phatg20.net. This link would seem to no longer be valid. Was this for a service manual or parts diagram?? Any idea where I can get a diagram of the parts that are in play here??

Sincere thanks in advance,Gary

[suncoach]

Gary,

You should be able to view the images now. Sorry about that. Let me know if you can't see them. I still have them and can send.

This is absolutely a DIY job - no need to pay $500 to have it done.

Here is another link for the FSM however they charge for the download: http://store.payloadz.com/deta....html

I still have the download - its about 45MB. Too big to email but I can upload the file if you have an FTP or storage site. You may not need it though for this repair since I posted an image of the page related to this part in the post.

Hope this helps.
Modified by suncoach at 1:32 PM 1/3/2010

[Q451990]

FSM download is available here.

Heath
Modified by Q451990 at 3:37 AM 12/31/2009

[Pwnin O'Brien]

MODS:

Do you think we could get a copy of this thread on the Pathfinder/QX4 section? This problem is all too common on the R50 and these are the best pictures/instructions on this issue to date.

Thanks!

[garyd333]

Thanks for reposting the pics! Perfect.

I found the FSM for 2001 QX4 here on the NICO site (we have 2002, so I figured it was probably close enough for what I was really looking for).

Again, thanks a ton!

Kindest regards,Gary

[RB2330]

Suncoach (or anybody else who can answer),
I Got the same "large" gasket from a local Nissan dealer in AZ and when I disassembled everything the Nissan one was thinner but larger. It appears yours fit anyway. Did you have the same confusion at first when comparing them? I ended up cleaning the oil cooler and old parts and put it back together; thinking I needed the "infiniti" part. It stopped leaking for about 3 weeks, but its back and with a vengeance. I still have the Nissan O ring.
Any suggestions?

Thanks in advance

P.S. your step by step post is top notch!

[Q451990]

to NICO RB!

Hopefully someone will come along with an answer soon! Is it possible that the one that was in your cooler was just squished down to make it look larger and flatter?

Heath

[SteveTheTech]

Sounds like the wrong gasket.

I think there are only a few that fit just about every car Infiniti makes. Some cross over there are a few that are way out there. I know the one from the FX won't fit the Qby4.

What was the Part Number?

[Qx4infiniti]

My 2001 infinitiqx4 started leaking from the oil cooler after switching from regular oil to synthetic. Do you guys think the synth-oil caused the problem, just wondering.

Thanks

[Towncivilian]

No. Synthetic oil may have cleaned up a "false seal" - deposits stopping a leak. Correlation is not causation.

Luckily, the oil cooler O-rings are simple and inexpensive to replace.

Welcome to NICO!

[nico911411]

[Towncivilian]

You should drain the engine oil before replacing the O-rings, but you do not need to disconnect the coolant lines.

[nico911411]

I didn't need to drain oil and got only a bit of oil draining out when I unbolted the cooler.

It's clean and not leaking any more. Easy fix!

[Towncivilian]

Oh, I had assumed draining the oil was necessary. I guess it makes sense that it'd be fine without draining the oil; same concept as changing the oil filter alone. Thanks for sharing your experience!

[Qx4infiniti]

Can you guys share the o-rings part numbers

Thanks

[fastpakr]

:-) Look up about five posts, they're shown as 21304-17F20 and 21334-30F00 in the last picture.

[yquinto]

thank you fastpark. I have same problem on infiniti qx4 2003 very nice of you now I can go and get the parts I need and have my qx4 fix. yquinto

[yquinto]

thank you SUNCOACH now I can fix my infiniti 2003 qx4

[BoostMyQX4]

Dont want to open a new thread so im going to ask here on this one since its about oil leak.
As i was bleeding the brake lines the other day i noticed oil on the bottom so i decided to take pics today and ask for help to figure out where are these 2 leaks coming from.

[Towncivilian]

First one is the rear main seal. Clean up the area and see if it is still leaking. High mileage oil may slow down this leak, since high mileage oil contains extra seal conditioners. I would recommend Valvoline MaxLife.

The second one may be oil dripping from a valve cover gasket. Make sure all of the valve cover screws are tight.