Need opinions on potential oil pump leak (1 Viewer)

[NoogaCruiser]

Hello friends, what started off as a simple TB/WP service appears to have gotten more complicated as I’ve discovered an excessive amount of oil around the oil pump area. Adding a few pictures for opinions before I move forward. The last pic shows the crank seal which appears dry. Truck is a 99 LX with 270k miles. Thanks for any opinions/advice!

P.S. I should add that the timing belt and water pump didn't appear to be very old despite the sticker saying it was last done at 107k and 15 years ago. So perhaps this is residue from a previous leak that has been resolved. Also, I noticed one of the TB idler bolts had fresh oil on it when it was removed (can't remember which side).

 

[NoogaCruiser]

It was the tensioner pulley bolt that was wet. Is this normal? Does it need to be sealed when reinstalled?

 

[3_puppies]

1 of those bolts needs sealer on the threads, I can't recall which one without looking at the FSM
it very well could be that bolt and that is your issue.

 

[NoogaCruiser]

1 of those bolts needs sealer on the threads, I can't recall which one without looking at the FSM
it very well could be that bolt and that is your issue.

I see what you mean. Just checked the FSM and it does recommend sealer.

 

[NoogaCruiser]

I see what you mean. Just checked the FSM and it does recommend sealer.

View attachment 3217986

Wonder if this could be the culprit?

 

[Mike NXP]

I see what you mean. Just checked the FSM and it does recommend sealer.

View attachment 3217986

Thanks for sharing that, I wasn't aware of that either but I also took the lazy way out and had Toyota do my t-belt job. Hope they know what their doing =] lol

 

[NoogaCruiser]

Thanks for sharing that, I wasn't aware of that either but I also took the lazy way out and had Toyota do my t-belt job. Hope they know what their doing =] lol

At the rate this is going I would say you took the smart way out! lol

 

[JunkCrzr89]

Yes, supposed to be FIPG on that tensioner bolt. Looks like the crank seal is also leaking.

 

[OEMGUY0720]

I have a similar leak and I think it’s coming from the oil pump or engine oil cooler?
This is where the weep starts at this highest point. Higher part than than is bone dry.
Oil pressure thread is bone dry.
The two inlet and outlet hoses and their clamps are bone dry.

Has anyone tackled this before? How do I remove the assembly and any special tool to use?
260k miles on the clock and I believe this has never been serviced/replaced before. Would appreciate any inputs at all.

 

[JunkCrzr89]

I have a similar leak and I think it’s coming from the oil pump or engine oil cooler?
This is where the weep starts at this highest point. Higher part than than is bone dry.
Oil pressure thread is bone dry.
The two inlet and outlet hoses and their clamps are bone dry.
View attachment 3253734View attachment 3253733
Has anyone tackled this before? How do I remove the assembly and any special tool to use?
260k miles on the clock and I believe this has never been serviced/replaced before. Would appreciate any inputs at all.

I replaced that o-ring when I replaced the oil cooler hoses. It’s easy.

 

[abuck99]

if you go in that far to replace that larger o-ring take the extra step and replace the figure 8 ring behind the oifilter mount. That usually leaks before the larger Oring. Also replace the cooler lines too-(#mission creep)

 

[OEMGUY0720]

I replaced that o-ring when I replaced the oil cooler hoses. It’s easy.

How easy is easy? I saw a video but its for a 96-02 4Runner and he removed the middle 24mm bolt.

is that the same with our 2UZ so I can separate the housing and access the oil cooler O-ring gasket (part #90301-67004) ?

if you go in that far to replace that larger o-ring take the extra step and replace the figure 8 ring behind the oifilter mount. That usually leaks before the larger Oring. Also replace the cooler lines too-(#mission creep)

View attachment 3253852View attachment 3253854

Thanks for this I saw one a youtube video with the same engine but in a Sequoia:

However on this video he only illustrated how to replace the figure-8 gasket part # 15692-50020 but not the main oil cooler O-ring part number 90301-67004.

 

[JunkCrzr89]

is that the same with our 2UZ so I can separate the housing and access the oil cooler O-ring gasket (part #90301-67004) ?

Yes

 

[OEMGUY0720]

Appreciate it @JunkCrzr89 thank you.

 

[JunkCrzr89]

Appreciate it @JunkCrzr89 thank you.

Put a little bit of silicone-based grease on that o-ring so it stays in place when you’re putting it back together. IIRC, I used a dab of dielectric grease.

Also, as I noted above, I replaced that o-ring when I was replacing the oil cooler hoses. If your hoses are fine, they should have enough flexibility to leave them attached to the cooler housing while you remove and install the o-ring, thereby preventing coolant loss.

 

[2001LC]

I've done a lot of 4.7 2UZ timing belt services, on 98-07. From 80K mile up to near 400K miles. Most services, I'm coming in behind someone else T-belt service.

In most cases, where I'm coming behind someone. The bolt threads of tensioner 10mm hex head bolt, have not be sealed. This bolt's hole penetrates the oil pump housing, into crank case area. Which they always leak oil if threads not sealed. It is number one leak seen at front of engine weep hole and right side after a Timing Belt service.

I rarely see crank or cam seal leaks, unless those seals replace before.

I see some signs of oil pump O-ring weepage, in all these days. Which as rubber ages, it shrinks and hardens.

As much as I hate any leak. Which with most oil pump O-ring, will not be measurable on dip-stick in 5K miles. We can live with.

I've only seen in engine run on HM oil (High Mileage oil), leak more. HM oil if used 2 oil changes, is the kiss of death to our seals. But still we can mitigated and live with some leakage. Provided levels kept up. Also provided, we keep rubber bushing clean of oil. Like steering rack bushing. Subject those to much ATF or engine oil for to long, they'll fail prematurely.

Today, I'm preemptively adding AT-205 treatment to engines. The older, the more I'll weight in my consideration for treatment.
I first run synthetic oil one or 2 cycles, in engines I suspect have gunk build up. Which helps clean the engine internally.
I then do a engine oil flush, with 2 cans of BG EPR and drain. Which works so comes with a warning, do not use in heavily gunked engines
After which I add 9.5 to 10.5 OZ of AT-205 into engine synthetic oil (M1 5W-30) engine oil. We need the seal clean, so AT-205 can soak into them.

Bottom line our rubber seals our aging. We may be able to buy many years. But, some day, engine reseal will be come common place.

All add: The worst leaks I've seen. Have been on engine run on HM oil (High Mileage oil). We are seeing some reduction of oil leaks in engines run on HM oil, using above procedure and AT-205. But it will not stop the leaks of damaged seals. The HM oil damages the seals, which only replacing can correct.

 

[JunkCrzr89]

All add: The worst leaks I've seen. Have been on engine run on HM oil (High Mileage oil). We are seeing some reduction of oil leaks in engines run on HM oil, using above procedure and AT-205. But it will not stop the leaks of damaged seals. The HM oil damages the seals, which only replacing can correct.

I agree with this, based on my anecdotal experiences. Many years ago, I had a Toyota pickup with 250k miles that barely leaked any oil other than from the valve cover gasket. But ignorantly I let some old timer at Advance Auto Parts convince me that it needed HM oil to help the bearings, etc. Within 2k miles of putting that junk in the engine it started spewing oil from all over the damn place, and then the timing chain broke and trashed the engine.

 

[2001LC]

Oil filter housing & bracket O-ring and figure 8 O-ring.

My first reseal of figure 8 O-ring. Was because figure 8 O-ring, slipped during install. I've use a sticky/thick assemble lube, to hold them in place every since.

The most common reseal I do. Is after a steering Rack & Pinion replacement. Most shop use the FSM method and pull the oil filter housing & bracket during the R&P R&R. Resulting in leak.


Interestingly:

Two in a row last month during timing belt service, and reseal of oil filter housing & bracket. I found they did not replace the "stays".

The Stay(s) on the 100 series, are two parts (brackets) plus a bolt joining the two stays. One is on the oil filter bracket, w/two bolts passing through. The other is on the AC compressor, w/one bolt passing through to fan bracket. They're joint by one bolt.

In one I just replaced both missing stays, which I also had to reseal oil filter housing and bracket. The upper bolt passing through AC into and securing Fan bracket, was also missing.

In video above 4.7L Sequoia, the stay is different. But notice in the end during assemble, he too did not put the stay back in. Which stay can be seen in beginning of his video.

Toyota engineers had their reason for these stays. So I do install them!

Why are they're being left out. I suspect, most are just forgetting to place back on. Some shop have learned, assembly is easier without stays.

Missing stays

Stays in place

 

[OEMGUY0720]

Yes I see that “stay” metal bracket @2001LC in my LX that definitely is going back in. I like everything oem and totally understand why the Toyota engineers put it there.
@JunkCrzr89 That’s crazy how high mileage oil created a leak and eventually affected the timing chain that lead to the engine failing. I’ll stick with non-hm oils still. I have ordered the parts including additional tools like the hose clamps and hose clamp pliers which will be coming in next week, will also do a full engine oil exchange while at it. Thanks for all your help although the dissent skids are made out of aluminum, removing them 5x now aint fun.

 

[jsloden]

When doing the timing belt on mine with 450k these were the only two places where mine was leaking. The figure 8 gasket and the big o-ring. When I pulled them off it was evident that more than likely they had never been changed. I put a little bit of silicone grease on them to hold them in place when reassembling.