Hey guys,
I took my car to a shop today for an inspection, just to make sure the 4runner(this is the v8) was in good health. And they told me I have a coolant leak. I didn't notice it before and I normally would notice something like that since I do my own oil changes and such. I asked them to look further into it and they said it was coming from behind the timing cover and that it was either the water pump or possibly a head gasket leak.

I'm wondering if this is a coincidence but I did do some off roading last saturday and I accidentally jumped the 4runner a bit on a sand dune. I was hoping someone might have some insight since I really can't afford a head gasket job. I can barely fork over the money for them to r and r the waterpump, so I really hope it was a bad water pump job. I had a work friend who is a technician do the timing belt and water pump just 20k ago. Obviously the first course of action is contacting him but I'm not sure I'll be able to get a hold of him since we no longer work together. Also to note the car never overheated and I never actually saw it go low on coolant.

I know some of you guys are mechanics by trade and I'm hoping for some insight weather its likely it would be a head gasket and its not worth getting the water pump looked at. Or fork over the money for them to check out the water pump. I have read that the water pump o rings can fail if installed wrong. here is some pictures i took under the drivers side of the engine.

Really hoping I can get this fixed ASAP since I have a 1400km road trip next friday.


EDIT: I don't see the image so here is a link Imgur: The magic of the Internet

The water pump weep hole drains out on the AC Compressor side of the engine and if it leaks long enough the bottom of the timing belt cover by the crank.

Most likely a water pump leaking, when was the last time you had a timing belt replaced?

I would probably point to the water pump before pointing at the head gasket if I had little information. It doesn't look like much of a leak. Watch it for a couple weeks and pay attention to the coolant res to determine how much you are actually losing.

*Edit* This may be more anecdotal than informative, but when I did my Timing belt I didn't add grease to the o-ring on the water pump where it fits into the block and damaged the o-ring. I ended up having an EXTREMELY slow leak that required digging back into the whole job and replacing the o-ring. It took me about 15k miles to notice that I was losing coolant and that is when I replaced it.

You are the exact person I was hoping would reply lol,
I had it replaced by a work friend 20k ago (he's a tech) but we no longer work together so I'll try to get a hold of him anyways. I did find your TB tutorial tho so I think I could follow that to get to the WP. I'm wondering if it's just a bad o ring or a bad FIPG bead, should I just replace that or should I put a whole new kit in?

If I had to guess that is exactly what happened, I definitely remember my buddy putting grease on the o ring but I've been seeing tons of examples of water pumps leaking if something wasn't sealed properly. And it drove it about as much as you did before i noticed a very slow leak. How long after you noticed the leak did you end up digging back into the WP and did you replace just the o ring or did you need new WP gaskets and such.
Also I've been reading up on your TB replacement tutorial

I have a 2005 4runner with the OEM AISIN Water pump. I have 150,000 miles on the car - owned it since new.

Recently I went to add some fresh coolant and tried draining the radiator by using the drain plug on the bottom. After getting about a quart of coolant to drain in an hour, and seeing that was looking like new (with no sediment) I aborted the change.

For the next few weeks the coolant level dropped in the overfill canister and I went through all the questions of these posters until a friend mechanic told me I let air in the radiator.

In the future, if you change your own coolant take off the bottom hose. The 4runner holds a little over 2 gallons of coolant.

My coolant level in the overflow canister is holding steady again, after a month of being high/low and in between.

As for the serpentine belt, it is OEM too. When a mechanic was changing my AC compressor I handed him a new belt but he handed it right back and said the OEM was still good!

The radiator on my 2005 4runner is OEM also.

In 15 years I've never had a tripped code or CEL on the dash.

Had the Toyota dealer do a tranny flush at 105,000 miles. They used 6 quarts of T-IV which is what came with my 2005 (not WS), so the next D/F will be 6 quarts (1/2 of my tranny fluid), and I'll take it back to the dealer - as she shifts fine with no slips at 150,000 miles now. 4runner tranny's hold 12 quarts so changing 1/2 is fine - I'm happy with that.

The 2UZ-FE's can be a bit of a pain to bleed sometimes, they'll get a big air pocket in them every now and then that's a pain to burp; more so on the Tundra/Sequoia but can still happen on the 4Runner as well. Best way to burp them is with a coolant funnel, the vehicle set to max heat, and running it off-idle (about 2500RPM, nothing crazy) for about a minute or two and then letting it rest and repeat if you still have some big bubbles. The rest you can compensate for by filling the reservoir to a little above the Max line and giving her a good quick freeway jaunt.

There's two drain petcock valves on the side of the 2UZ-FE & 1GR-FE block, the driver's side one is a bit of a pain to get to; I prefer the passenger's side one. Use two flexible hoses, one for the radiator drain, and the other for the block drain. Between those two and letting it drain for about 10-15minutes (you did have the radiator cap off right?) you should get most of the coolant out of the block and radiator, also less of a mess.

I'm suspicious of the original drive belt being fine after 15yrs and 150k, that seems rather exceptional to me. But not there and didn't see it so, if he says so.

I'd whip out my torque wrench and re-torque the water pump bolts to factory spec before tearing into it.

If I'm into it that far I might as well replace everything and not take the risk of having to dig back in.

Sure, but if any of the bolts turn before reaching torque spec you have a likely cause and correction. It's a good diagnostic in either case, whether you stop there and reassemble or continue with replacement.

I see what you mean, I'll definitely do that then. I'll make sure to mark the torqued bolt heads as well.

captsolo!!!! Busted!!!

LOL, I was thinking the same thing. I had to double take the username

I thought this sounded suspicious


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