Stubborn Oil Leak...Need help identifying source.

Hi all,

Have a 1998 2.7L Taco that's had a small oil leak ever since I bought it from the previous owner (convenient). I've been ignoring it for the better part of the summer now, but the droplets on the driveway are beginning to add up and I figured it'd be best to solve it permanently.

At first, I thought it was the oil pan. So I removed it, cleaned very thoroughly, and applied new FIPG...Only to find the leak still remained. I assumed I must have put the FIPG on incorrectly, so I took it off (again) and tried a second time being extra careful. I knew I was dead-on this time and still, the leak remained. So after that endeavor, I kind of gave up for a while until now.

After looking more closely it looks like it may be from the oil pump?

See video here: https://www.youtube.com/watch?v=ndx3Eq2yUZE

-1st angle is looking through the side of the front skid plate at the oil pump from the passenger side.
-2nd angle is underneath.
-3rd angle is above looking downward past the belts.

This looks like a total pain to deal with but would love to hear from anyone else more experienced before I dive into it.

Thank you!

 

I went down an oil leak rabbit hole before. Thought it was the oil pan and front crank seal. Both were fixed and the leak remained.

check you oil filter mount, there are 2 o-rings where it meets the block.

If you have coil packs there is a seal behind the mount for them. I discovered a leak here after putting dye in the oil.

check your rear main seal as well. I now have a slow leak here that is not worth fixing. It requires removing the whole transmission.

 

Not sure where it's at on yours (I have a 2nd gen) but I had a gremlin like this and suspected the valve cover gasket and then the oil filter..turned out to be the pressure sending unit, easy fix

 

Oil pressure sender is on that side of the block too. Mine was broken and leaking. Its been a year, but I'm pretty sure its that white connector.

 

Looks kinda like the front seal. If it’s not that I’d double check the timing chain cover even though yours looks pretty clean going down the side

 

I suggest degreasing the engine heavily so there is no sign of wet oil anywhere. Then put a tracer dye in the oil and use a UV light to find the leak after driving enough to show oil on the engine.

$8 InterDynamics Certified Auto Pro Oil and Fuel System UV Dye Leak Detection for Cars & Trucks & More, 1 Oz, 374CS, Universal

https://www.amazon.com/gp/product/B002M4G24U?ie=UTF8

$16 InterDynamics Certified A/C Pro Car Air Conditioner Stop Leak Detector Kit, Leak Detection Kit Detects O Ring and Hose Leaks, Includes Protective Glasses and Pen Light, InterDynamics

https://www.amazon.com/gp/product/B003JOB594?ie=UTF8

I was able to successfully diagnose a rear main seal leak (as well as others with this). Don't just guess, plan it out and find the source.

 

Working with Hydraulics I use brake clean to clean oil leaks so it drys quick, run the engine and check all over, you will find it, good luck.

 

2.7's have a problem with the oil filter mount leaking.

 

Hi all,

Wanted to revive this thread because I finally had some free time to clean some oil and I actually pin-pointed exactly where the leak is coming from:



So I'm dead certain this is the leak, because it's repeatable. Immediately after turning the engine on a small pool will form right where the dipstick connects to the engine, in the video you can even see it seep out. Is it possible that the dipstick tube is causing the leak? I've never heard of that before but it's the only thing I can think of. Let me know what you guys think based on the video.

 

have you checked to see if there's an O'ring that could need replacing. when was the last time you changed the PCV valve. It could be causing undue pressure in your engine forcing the oil out the dip stick tube.

 

No idea if there's an Oring down there or not. Also don't know when the PCV Valve was changed. I bought the truck last year at 170K no clue when the previous owner would have done so. I looked it up though and I'm reading up some horror stories of the grommet falling into the engine and then the whole valve cover has to come off

 

yes,you have to be careful when removing the grommet. Take the PCV out and shake to see if it rattles. If the grommet is brittle, just be extremely careful removing it. I had to use a flash light and a 3 pronged grabber gizmo to get out my broken pieces.

 

There is definitely an o-ring there, I have replaced it before. You definitely want to just replace the pcv valve since you don’t know how old it is. It’s only $10-15 and quick and easy to replace.

 

So I pulled the dipstick tube out by just undoing one bolt that holds it like a bracket near the top of the engine and saw that Oring on the other end. Honestly it looks fine, still rubbery and not brittle at all. What confuses me is what that bolt is right next to where the dipstick tube meets the engine, almost like it’s the dipstick tube holder? Does that make sense? That’s the bolt directly where I think the small oil puddle is releasing from in the video.

Also ordered a new PCV Valve.

EDIT: Found out what it was thanks to the handy Hayne's! It's a Timing Chain Cover bolt, 12mm size, torque 14 ft lbs. I'm gonna see if I can fenagle a large extension to try and get it out without removing a bunch of other stuff, put some sealer around it, and hopefully get it back in there. Will report results!

 

Absolutely easy fix.
You have to order the special configured gasket and replace it. Its made of neoprene like an O-ring.

 

Did you ever fix the oil leak - and was it the timing chain cover bolt? Any details you can provide will be awesome. Got this issue on my 99 and it's driving me crazy. I see the puddle exactly like you did, even bought a cheap scope that plugs into my smartphone to try and "see" the leak (didn't really help).

 

OP hasn’t been on the Forum for over a year. Might be kinda difficult getting a reply.
Hopefully someone else in this thread will be able to help you.
Good luck!

 

Have you replaced the distributor oring? Mine was leaking very bad.

 

Saw this thread revived without a definite resolution. I’m experiencing the identical symptoms. 2000 2.7 with 251k. Did the valve cover gaskets and replaced the pcv valve at that time with 159k. Will check the pcv next chance I get. Any advice would be appreciated.

 

So I believe I have narrowed my issue down to my oil pump. After months of on and off research, I finally found some videos that pointed me in the right direction. So I went under the Taco yesterday and am 99.99% sure my issue is the oil pump o-ring. I read that this is a fairly common issue, and given I don't know if/when mine was ever changed since I'm at almost 329k, I think it's time I change it. Below are 2 pix from my video pointing to oil leaks.

The first shows clean oil pooling at the seam of the oil pump (just changed the oil last week), and the second is a little further to the right of the oil pump where the first red arrow points to the source of a leak that drips down onto the oil pan rim making it look like the pan is leaking (which it could still be, but everything points to the oil pump).

I don't have a pic of the top of the oil pump, just under and to the right of the base of the dipstick (I did put a new O ring on it) where oil pools up actively when the Taco is running.

Hoping this is helpful to anyone. I did order the following from ICE so I can do the replacement (hopefully this coming Saturday).

1016080 Oil Pump Cover Allen Head Hardware Kit - 2RZ/3RZ - $17.09
1016085 Oil Pump O-Ring 2RZ/3RZ - $9.26
1017026 OEM Front Seal - 2RZ/3RZ Front Balancer Seal (1996-2004) - $12.97