2UZ-F2 Cam Seal Leaks (1 Viewer)

[marcjs]

Question for the 2UZ experts...

...I recently rebuilt my son's 2UZ-FE top end after a blown head gasket. After reassembly and fire-up, oil leaks arose from the front cover below each of the valve covers. I asked my local dealership's master tech about it and he inquired how I went about installing the camshaft oil seals, to which I replied that I tapped them in as per the FSM. He told me they don't do it that way due to seals being damaged when pressing them in. Instead they adopted the process of installing the seals along with the camshafts into the head and then clamping the bearing caps over them. Using that method they never damage the seals. UGH!

So I purchased another set of cam oil seals and disassembled all over again. After pulling the timing belt, camshaft timing pulleys, and timing belt plates, a couple of small puddles were visible on the flange of the forward bearing housing. That was reassuring, because prior to that I was questioning whether the leak could be coming from elsewhere!

Before proceeding further, I was wondering what the function is of the hole below each of the camshafts??? I poked a scribe inside to gauge how far in the went and it had me wondering whether oil could be making its way out through them. I could investigate where they lead to by pulling the camshafts out entirely, but I'd prefer not to loosen all the camshaft bearings just to satisfy my curiosity.

Thanks in advance for the answer.

-Marcel

 

[neoworm]

I can confirm for you that that hole continues through to the inside of the head but I can't tell you why it's there. Oil could certainly pass through it but the seal should still prevent it from going any further.

 

[neoworm]

Oh and just an FYI i've tapped in many of those seals as per the FSM and never had a leak. Maybe you just got unlucky?

 

[marcjs]

Neoworm, thanks for the quick reply.

I've tapped many a cam seal in also without issue, so it surprised me when he said that. This was my first 2UZ-FE rebuild, so it made me wonder whether the interferance fit wss just too tight for the seal in the bore or what???

 

[awesomeissquid]

The front of the head has a number of oil passages. Like @neoworm suggested the oil seal should seal the oil in. Are you putting the FIPG around the edges of the seals?

 

[neoworm]

Ya clean up that seal mating surface and put a really light coat of FIPG on the new seal. Helps it go in and gives a bit of sealing insurance.

 

[dbleon]

I thought the t type oil seals we’re supposed to be installed dry on the outside and lightly oiled on the shaft side … ?

 

[neoworm]

I thought the t type oil seals we’re supposed to be installed dry on the outside and lightly oiled on the shaft side … ?

That could very well be correct. A mechanic friend who I trust told me to do it that way a long time ago and it has never failed me so I stick with it. We are talking a very light coat, just a tiny smear. and as you said oil on the shaft seal.

 

[awesomeissquid]

Timmy the tool man also talks about it in his timing belt video I believe. I think that is where I learned about it. Just helps seal everything up. Hope this solves it.

 

[OregonLC]

What a pain. That discovery, no doubt, required complete removal of the timing belt again. I hate surprises like that. It's enough work to do the job once.

I have done five 2UZ jobs now, every one with new cam seals and never had an issue. No FIPG, light motor oil on seal touching cam.

Before you pulled them out, could you tell if they were leaking from the center or from the perimeter? The way that FIPG shows in the pic, it appears that it would be creating a ridge which would allow oil to seep. Was this after the leak and the seals were pulled?

In answer to your question, the hole appears to be just a drain, giving any oil that made it forward a relief path.

BTW, great job on tackling the head gasket yourself. How was the job other than this?

 

[marcjs]

What a pain. That discovery, no doubt, required complete removal of the timing belt again. I hate surprises like that. It's enough work to do the job once.

I have done five 2UZ jobs now, every one with new cam seals and never had an issue. No FIPG, light motor oil on seal touching cam.

Before you pulled them out, could you tell if they were leaking from the center or from the perimeter? The way that FIPG shows in the pic, it appears that it would be creating a ridge which would allow oil to seep. Was this after the leak and the seals were pulled?

In answer to your question, the hole appears to be just a drain, giving any oil that made it forward a relief path.

BTW, great job on tackling the head gasket yourself. How was the job other than this?

View attachment 3217936

I couldn't tell whether the leak was coming from the outside of the seal or the inside since the vehicle had sat for weeks before I could face revisiting the job.

In regards to the degree of difficulty of the rebuild, it wasn't bad at all. I had the valve seats and valves re-ground by a top-notch machine shop who also skimmed the valve stems to compensate for the valve clearances. I nonetheless reset all the shims to be mid-range on clearances afterwards, which was a bit of an iterarative process, but I'm a bit anal about keeping things as close to mid-tolerance as possible.

Perhaps the worst part was replacing heat-embrittled electrical connectors in the "V", as well as removing/installing the starter motor. I took the opportunity to fit a new higher-torque starrter while I was at it.

All-in-all not a terribly difficult job.

 

[blinkerfluid]

Question for the 2UZ experts...

...I recently rebuilt my son's 2UZ-FE top end after a blown head gasket. After reassembly and fire-up, oil leaks arose from the front cover below each of the valve covers. I asked my local dealership's master tech about it and he inquired how I went about installing the camshaft oil seals, to which I replied that I tapped them in as per the FSM. He told me they don't do it that way due to seals being damaged when pressing them in. Instead they adopted the process of installing the seals along with the camshafts into the head and then clamping the bearing caps over them. Using that method they never damage the seals. UGH!

So I purchased another set of cam oil seals and disassembled all over again. After pulling the timing belt, camshaft timing pulleys, and timing belt plates, a couple of small puddles were visible on the flange of the forward bearing housing. That was reassuring, because prior to that I was questioning whether the leak could be coming from elsewhere!

Before proceeding further, I was wondering what the function is of the hole below each of the camshafts??? I poked a scribe inside to gauge how far in the went and it had me wondering whether oil could be making its way out through them. I could investigate where they lead to by pulling the camshafts out entirely, but I'd prefer not to loosen all the camshaft bearings just to satisfy my curiosity.

Thanks in advance for the answer.

-Marcel
View attachment 3217807View attachment 3217808

first of all, clean that black protruding fipg

that small hole is the oil drain hole, oil that is sloshed around behind the seal gets drained thru that hole.
Does the camshaft have any 'depression' ring around the area where the seal runs?

 

[blinkerfluid]

That could very well be correct. A mechanic friend who I trust told me to do it that way a long time ago and it has never failed me so I stick with it. We are talking a very light coat, just a tiny smear. and as you said oil on the shaft seal.

You can also use grease for that purpose

 

[blinkerfluid]

Neoworm, thanks for the quick reply.

I've tapped many a cam seal in also without issue, so it surprised me when he said that. This was my first 2UZ-FE rebuild, so it made me wonder whether the interferance fit wss just too tight for the seal in the bore or what???

have tapped those into 2uzs many times without problems

 

[abuck99]

@marcjs What version 2UZ are speaking about. 06+ VVT or 05 & earlier?

Onlookers- the cam seal install process very different for VVT- where cams must be removed vs pre 06 which can be replaced by simply removing the cam gears and pulling old and inserting new.

Putting FIPG or RTV on the sealing surface of seals is kind of an old school practice, on American autos where tolerances aren’t as exact or where many shops might use aftermarket seals which we know can be prone to leak. I don’t think it’s necessary to use FIPG on seals when using Toyota seals in Toyota engine or transmission components. It won’t hurt but it’s a pita to clean off when you go to replace next time.

The pre 05 2UZ cam seals simply get pushed in/tapped in place (dry). No need to remove cams (unless VVT).

 

[trdcorolla]

If I had a 98-05 non vvti, I would always change the cams seals while your in there. If I had a 06/07 vvti with documented proper mileage oil changes intervals I would not change them. If I had a 06/07 with a neglected/unknown oil change history vvti I would replace them.