Q-DawgVFR

Hooray for me. I get the pleasure of replacing my water pump and timing belt now. My earlier block heater blow-out led me down the wrong path, as I initially assumed that coolant from the block heater leak had somehow migrated (via the oil cooler hose) to the front of the engine at the thermostat housing as I had spotted coolant there earlier. After replacing block heater and cleaning engine, I saw no further coolant at the thermostat housing. Until now.
My wife had taken the truck for a drive to the city and I was to meet her there later in our car. When I went into garage, there was a SMALL puddle of coolant about 3-4" diameter. Great. In the city, I noticed a dime sized coolant spot in snow under truck. Popped hood and saw the coolant on thermostat housing. After determining that the leak was minor and that rad and reserve were still pretty full, I drove home. No real noticable drop in reserve tank level after vehicle cooled off.
Pulled upper timing belt cover back and removed battery for a clearer view. It seems that the water pump is seeping pretty noticably from the gasket behind it (drivers side of pump) where it mates to the engine block. I figure that the timing belt looks aged (horizontal cracks accross the entire belt width on the smooth side of the belt), and that the water pump should also be replaced if I am going to go through the ordeal on my own of fixing the leak. Perhaps at the same time I will try to fix the oil seepage (minor) from the valve covers.
My question for all of you is this: how long do you think I should wait before attempting this work? Could I get away with driving the truck for a couple of months to do it at a more convenient time? In my opinion, this has been seeping for a while (quite a bit of dark green residue built up along pump gasket) and the leak is pretty minor. It took about 2 weeks of driving for the leak to find its way to the bottom of the engine and to start dripping onto the ground.
My financial situation is tight for the next 2 months as my wife has just started nursing school and I've spent thousands on books, tuition, etc. and my car is coming up to the end of its lease this month and I wish to keep it.
I'm thinking that with monitoring the level of the coolant (and rate of leakage underneath vehicle) I could likely get away with it. I have a third vehicle if this one dies; so I'm not too worried about downtime. I also have AMA gold membership if it I'm forced to stop because the leak gets suddenly worse. Should I try some sort of coolant leak stopping liquid product to see if it will seal up the gasket leak? I'm interested in all of your opinions on this!

MTL_4runner

First, absolutely do not ignore the problem and hope you can escape unscathed! Second, do not use any "quick fix" products because again cutting corners will likely cause you big headaches later (not to mention that the stop leak products seldom work the way you'd hope and often do more damage than good). The cracks in the timing belt indicate that you likely have a limited amount of time (how much is anyone's guess) before it leaves you stranded on the highway on a nice warm Alberta's winter night......just pray you have a cell phone with you when it does. I go ahead and do the timing belt and change the W/P just as insurance (esp if you are intending to keep the truck any period of time). Do the proper maintenance required before it costs you alot more than that or park the vehicle and find other means of transport until you can fix it properly. I am being a bit harsh, but it is an important point that ducking the problem, no matter how strapped for cash you might be, is never a wise move.

Writeup:
http://www.4x4wire.com/toyota/maintenance/timing_belt/

bwhyit

if you can't afford to fix the runner then drive your 3rd vehicle.

Maj

I would advise against any coolant leak products. That stuff can potentially clog radiators and heater cores too. Since the leak might get on the belts (including timing), chemical deteroriation of the belt(s) will result. I dunno if 2 months is long enough for the belt strength to become compromised or not. Probably not. Replace all belts and clean the pulleys when you do go in.

Leaks typically get worse over time but I have gone months in other vehicles with leaking water pumps. The thing you need to keep an eye on is the water pump bearing. Water pumps have a weep hole for the coolant to escape when the seal goes bad. If the seal is bad, the pump bearings are being drenched in coolant and eventually will fail. If the bearing fails, the fan could potentially slice into the radiator or shear off the shaft altogether. Signs of bearing failure include a grinding noise and a fan that wobbles around when the engine is running.

If you decide to postpone the repair, check the coolant level daily (in the morning) as opposed to trying to monitor leak puddle size. Don't take long trips and be aware that continually topping off the radiator will dilute your antifreeze - not good a thing in your part of the country.

Q-DawgVFR

Thanks for the info on the water pump. I see no signs of a bad bearing (fan runs true and quiet) and the leak is coming from the GASKET on the pump, which is nearly the ONLY reason I am entertaining the notion of postponing the fix. The other reason is that I use a company vehicle to drive to and from work everyday, and don't use my personal vehicle often when I am at home. I am driving to Edmonton (250 Km one way) and back once every week or two to visit my wife and son, as she has gone back to school for 20 monthsto be a nurse. No driving other than that. There is Nothing actually wrong with the water pump itself as far as I can tell. There is no coolant on the timing belt at all (95% of the leak is outside the timing belt cover area.) I don't think that I trust these coolant leak products either; I logically don't see how they can work without causing the negative effects that you mentioned. My neighbor is a service manager at the local Ford dealership and I will get him to take a look at the leak; I know he will be honest about how serious he thinks the leak is and whether I can drive it for a while or not. I know he will tell me that I am rolling the dice (at least a little), but he's pretty good at telling what is about to fail immediately. I plan to factor his opinion and those of the knowledgable YT members into my choice to drive or not. I will be driving the 3rd vehicle at least once or twice to edmonton as i have a couple of furniture peices and an excercise bike to transport to my wife's location. So i think the 4Runner only has to hang in there for another 3-4 trips to the city and back.

MTL_4runner

One more hint on finding where the leak is actually coming from is that the coolant will glow under a black light. Now usually in the warmer temps you'd hose off the vehicle, go for a drive and come back and inspect but since we're already into subzero temps up here (and will be for a few months more), the best you can do is just look at what areas of coolant exist right now.

I really wouldn't trust it to go 250km in the middle of winter in Alberta without fixing it, but that's just me.

Q-DawgVFR

Oh the cracks in the timing belt do not go entirely across the belt and are not very deep. I agree that I would not trust the belt too long either, but I am pretty confident that it will not fail in 2 months. I have roadside assistance, a cell phone, and blankets, survival kit, first aid, flares, etc. And I will be on a well travelled highway with plenty of other motorists, so I'm not worried about being stranded a long time. If weather was very cold (-20 C or colder) I would drive vehicle #3 to reduce the risk. Vehicle #3 is pretty reliable, but the last time I drove it the speedo wigged out for 30 seconds and was all over the place before settling back up to the speed I was travelling at. I think it is just an isolated guage problem, but you never know 100%. And I try to avoid driving it in winter as it is 2wd pickup and has a thirsty V8. But I do trust it enough to rely on it if needed.

MTL_4runner

Ok, I just know how nasty winters are up here and getting stranded in -20 really stinks even with provisions.

Try the blacklight (cheap, availabe at walmart, Canadian tire, etc) trick with your neighbor and see how you guys make out. You can even post pics and we can try and help you with the diagnosis as well.

Q-DawgVFR

I respect that and thank you for your opinion. Hoping a few others will offer their advice. I can see very well where it has been leaking, thanks to heavy buildup of greenish black sludge (dirt mixed with coolant.) It looks like it could have been that way for months or even a year or more. I really don't know how long it has been leaking, because I bought the vehicle used at a car lot in November. I trust the 4Runner to be a reliable truck, but obviously there were some maintencance items that need to be addressed with it. Nothing too serious on a vehicle with 283,000 Km on the odometer. I worry most about cooling system and oil system issues on vehicles as they can kill engines fast. Lucky for me that Sparky (I've named the vehicle this because of the recent self induced electrical issues) has a new rad and fresh looking hoses.

MTL_4runner

These trucks are nearly bulletproof compared to most vehicles on the road, but they do still basic maintenance to keep them like that. You are right to be worried about the cooling system because that and the oiling system are the 2 most common causes of engine rebuilds. I know you mentioned a tight budget now, but I would honestly consider replacing the waterpump if you have 283k KM on what is likely the original pump. Otherwise you might be looking at having to do the same job twice (you need to remove the timing belt to get the waterpump out if it goes later) and possibly being stranded in winter. If it were my truck I would change the belt, W/P, thermostat and flush/refill with the toyota red coolant. Again I know dealer parts are more money, but if you're going to have the vehicle for some time, they are worth it in the long run.

Q-DawgVFR

Why the red coolant? All my gearhead friends (a few are in the parts and service industry and are mechanics by trade) have told me to avoid it like the plague as the same stuff that builds residue to show leaks also takes out water pump seals faster. That and they said it isn't worth paying extra for.

Q-DawgVFR

I'll definately use Toyota parts for these items. I beleive in OEM for critical parts (unless the original OEM part was prone to failure due to bad design in which case aftermarket is sometimes better.) And don't worry; I'm definately going to replace the pump when I fix the leak and replace timing belt, simply because the water pump is such a pain to access. I'm modding my upper timing belt cover to enlarge rad hose opening. Does anyone else besides me think it is stupid to not be able to slide it over the rad hose clamp? I want to be able to just take out the cover nuts and be able to slide it forwards for quick inspection once in a while to check for leaks, timing belt condition, etc. It bugs me to have the leak noticed now, since I JUST replaced all my coolant a few weeks ago to do the block heater replacement. Oh well, I guess I will try to salvage what I can into clean milk jugs and reuse it. No sense wasting it when it is brand new.

MTL_4runner

The short version is that asian designed imports (esp Honda and Toyota) need a phosphate based coolant because of the cooling system design (esp the water pump due to cavitation). Unfortunately you're mechanic friends are not correct if they are referring to Toyotas or Hondas.

If you want the technicals on why you need to use the OEM coolant, here's the thread (warning, possible info overload): https://www.yotatech.com/forums/f2/just-finished-timing-belt-coolant-question-77747/#post811900

Q-DawgVFR

That's a very good thread and explains the difference between a lot of the long life coolants. I still don't see what harm using the old fashioned green coolant will cause. You mention cavitation problems, but I don't drive at high RPMs. I see long life coolant as a waste of money on a vehicle with such high mileage; I would rather change coolant a little more often. If phosphate is really critical, I can always get a tiny amount from work (we use it as corrosion protection in an industrial cooling water system, and phosphates are wetting agents.) probably only need a few mL's worth.......

Just a little science for those who care:
Corrosion protection has many different types and some use different means of protection. Many use the idea of trying to separate the metal surface of the parts from the fluid being circulated. Silicates are more of a coating type of protection, while the organic acids and certain amines actually use a thin layer of corrosion to protect against further corrosion. This thin layer can take a while to build up (long life coolant) and can be damaged by comtaminants which attack its integrity (oxygen can be one example), or by high velocity (erosion or cavitation.) Some protecting agents like phosphates also keep contaminants suspended in the fluid and hinder their ability to deposit on surfaces. There's a lot more to all of this, but that's a quick and dirty summary of a few principles of operation.

MTL_4runner

That's why I mentioned about cavitation, the issue is far more predomonant on Hondas and Toyotas because of the waterpump/cooling system design. It also doesn't mean that just because you baby the truck during acceleration or on the highway that W/P cavitation won't occur. Most domestic vehicles have cooling systems which are designed to avoid cavatation altogether. Honda and Toyota took the other approach (not worrying about trying to limit cavitation) and just use coolant with phosphates in them. There is nothing wrong with using good old fashioned green coolant as long as you keep flushing it with fresh coolant about every 2 years. I prefer the OEM coolant because of the protection phosphates give you on these trucks and it usually lasts longer before needing to be changed/flushed. Again, I'm not telling you what to do and it's your call what you want to run in your vehicle, just giving you the facts so you can make an informed decision. I run the OEM stuff in mine because I feel the benefits are worth it.

Q-DawgVFR

Again, i really appreciate your input. You and I differ a little in our views, but that's OK. At least you explain why you feel the way that you do. There are so many posts (not on YT, but mostly on other forums) where people say "that sucks" but don't back their views up with any facts. Sometimes they just blindly follow others in buying a particular product and then start knocking anyone who wants to try a different approach. I learned a lot about coolant from your responses. I think I will stick with old green and flush more often. I will add some phosphate to reduce pump cavitation. It does puzzle me somewhat that Toyota and Honda would build water pumps prone to cavitation issues, though. They could have built the pump a little tougher. Might have weighed twice as much though. I chatted with my neighbor. He and another mechanic friend came over and looked at my truck. They agree with my assesment that this gasket has been seeping for a LONG time (guessing probably a year or more) and that it is a small leak that is very unlikely to get suddenly worse. Sooooooo........ After weighing both sides, I'm gonna continue driving the 4Runner for the next few weeks until I get replacement parts from Toyota and set aside some time to do the timing belt and water pump replacement. I'm sure there are some great write-ups here on YT which I will reference before starting the job. And I've got the FSM finally for the truck. I know there are a few special tools involved in timing belt replacvement; are they necessary or can you substitute another means? I'm thinking specifically about crank pulley removal, but perhaps there were a few other specialized tools for other job steps.

bosco659

Jamie has offered good advice, I would recommend taking it and fix the truck up sooner than later. If your truck breaks down on the long trip to Edmonton in this winter weather you will be sorry that the repairs were not completed earlier! As for the antifreeze - you have been provided with good techincal info and you can do what you want. I have always run Toyota red stuff in my Runner and Supra with no negative results.