24Tiki

Hi all,

New to the forums, so I apologize if this has been covered elsewhere. I did a search and didn't find much. This question is less about how to fix a leak than it is about the decision between conducting preventative maintenance and doing reactive maintenance.

Here's the rundown:
I've got a '91 4x4 pickup with a 22re. 235k miles on the rolling chassis, I'm not sure how many on the motor/ if or when the motor was rebuilt. The motor is plenty powerful, doesn't burn oil (that I can tell) and seems to have plenty of life left in it (making me think it has been rebuilt, in fact I remember the previous owner saying the owner previous to him had rebuilt the motor). I do regular maintenance and change the oil every 3k miles. I don't run the truck hard (pretty much stay on logging trails and the road) and the body is straight, indicating it's had a pretty easy life. I pulled the oil pan and redid the gasket with FIPG as per the FSM about a thousand miles ago after realizing I was leaking some oil. There are no signs of leakage from the pan since then; however, it looks like I am leaking oil from somewhere above the pan. I need to degrease the block and see if I can determine exactly where I'm leaking from, but my preliminary guesses are either the timing chain cover or front main seal.

My dilemna:
So, I know I'm leaking oil--more than I'd like (I like things to work as they should, to include retaining oil). I am trying to determine how deep I should dig. My options as I see it are to:
1) Pull the TC cover and install new gasket. If I do this, I would want to do it the right way and pull the head (I also kind of want to see what kind of shape the head is in, and do a new HG since I don't know when the rebuild was done). I would also do a new water pump, oil pump (and therefore front main seal), and have the head checked at a machine shop and have it decked if needed. I would also do the timing chain set with everything apart. Looking at engnbldr for all components and HG from toyota.
2) Do just the front main seal and oil and water pumps. Don't worry about the TC, TC cover and head gasket.
3) Keep feeding it oil. Technically, it isn't broken. Just a little leaky. This is my least preferred option, especially considering that in a few months, I will not have the time to do these sorts of repairs myself and because I have a decent size road trip coming up.

It's the struggle between: "If it ain't broke, don't fix it," and preventative maintenance. If anyone could offer their opinions or experiences, that'd be much appreciated.

Thanks.

coryc85

Well, I'd find out where it is leaking. There are plenty of places it could leak, front main, distributor, valve cover. If the engine is running fine, and if your tchain guides are intact, I would look hard at everything else before even thinking about touching the cover.

24Tiki

Yeah, I think that's good advice. I don't know if the guides are intact but I suspect they are, since I didn't find any plastic in the oil pan when I did the gasket. Best method for finding the leak is to degrease, go for a drive and then look for new oil right?

coryc85

Yep, degrease it, drive it and check repeatedly for fresh oil.

24Tiki

Great, thanks for the advice.

thralldad

If it's like mine the harmonic balancer has a groove worn in it.There used to be a crank seal that was 12 mm deep instead 8mm. The seal would ride past the worn area but I haven't found one in a long time. You could replace the balancer if it's leaking there..

24Tiki

I'll have to look into that if it looks like oil is leaking from the front main/ oil pump. Thank you for the info.

BlackPearl808

One possible leak to check is where the TC cover, the block and head meet. If a previous owner changed the timing chain without removing the head and didn't put enough care into applying FIPG where those 3 things meet, that would be my best guess where the leak would be. Before I did mine, there was oil leaking around/under where the dipstick.
Good luck!

24Tiki

I'll take a hard look at that area too, thank you for the advice! Planning on degreasing today and going for a drive to show me where oil's leaking from.

BlackPearl808

update?

24Tiki

The weather here has been poor the last few weekends so I haven't gotten under the truck. Hopefully next weekend will be dry enough to get under without getting soaked.

eurojoe

watch that video.

if you think your front main seal is leaking just degrease where the Oil Pump meets your engine and check later if there is a drip of oil sitting there.

24Tiki

Hi all, here's an update:

Finally had the chance to get under the truck and take a look. It is definitely leaking oil from the front main seal/ oil pump gasket. It also looks like there is a moderate leak from the timing chain, since there is a sludgy oil buildup along some of the edges of the TC cover above the oil pump.

The question now is: how far do I take this repair? I am leaning toward doing the whole deal: pull head, do head gasket, timing chain, TC cover gasket, oil pump w/main seal, water pump, anything else I'm forgetting. Alternatively I could just try to pull the oil pump, but I figure it will need done sooner or later.

What are your thoughts?

eurojoe

24Tiki

Thanks eurojoe,

I recently pulled the oil pan to do the oil pan gasket and it was clean, so timing chain guides should be intact. I've read/heard that if you pull the TC cover you disturb the head gasket material, and it therefore needs to be replaced (at least that's what I hear the "proper" repair is). Any validity to that? I don't think the head gasket is blown, the truck runs great and doesn't lose coolant or burn oil. The other thing is that I'm pretty sure there is at least a minor leak from the TC cover, so it wouldn't be THAT much more work to do the head gasket I don't think.

eurojoe

DISCLAIMER: I am a decently skilled ameteur, but im just offering my opinion. Do not take my advice as end all be all.

You do expose the front of the head gasket but you wont brake it off if you are careful. The FSM even describes putting gasket maker in the corner where the TCover meets the headgasket so it is a normal procedure. I did not replace my headgasket and all is fine.

Taking off the headgasket is a whole different animal from what I understand ( I have never replaced the headgasket). You need to resurface the head, resurface the block and clean off the old gasket. and you need to re-torque the screws holding the head down in a certain pattern. I bet it wil ltake you an extra day alone to remove and resurface and another day to replace.

This is my bottom line.
Check your compression, if it is weak. Do everything. Headgasket, tcover and oilpump. if compression is good, do your tcover and oil pump (leaving the headgasket for another day)