TStango

I made a last minute trip to Paragon last Saturday for some wheeling to try out the new locker. It was rainy and I had to run the AC to keep the windows from fogging up as I was climbing some crazy stuff on whompum. Next thing I know smoke is coming from the engine and the temp guage was pegged. The anti-freeze was boiling in the resevoir and spilling out all over the place. We waited for the engine to cool and filled the radiator with water to get me through the rest of the day. The temp stayed normal for the rest of the day but on the way home, I noticed a that the engine had a whining noise coming from what seems to be the top of the engine.
It sounds like it could be a bearing - maybe in the water pump but could it be something much worse? Just wondering if anyone else has experienced this and maybe could point me in the right direction.

TStango

Bump.

BOSTON4RUNNER

could be a water pump, however if the bearing was going, it would likely start to walk and would damage the belts, but maybe that has yet to happen

can you start it, listen to it in the driveway

do you have a scope? to try to pinpoint the noise

too bad you were not local, I could definitely diagnose it for you....

tim

SLC97SR5

Yeah, I'm thinking the same thing also. It took a dump under load and now that you babied it home all you hear is the bad bearing. Keep us posted. When you pull the pump you'll know real quick if it's bad, the impeller will probably be flopping around. Be sure to flush the block and radiator really good to get rid of any broken pieces of pump.

BOSTON4RUNNER

this is what I would do...check the simple stuff first, hoses, inspect the radiator, also while running see if thermostat has opened,,,,as such problems can cause, or point to other issues...

check the oil for its level, make sure no antifreeze is in the oil,,,case head gasket went or something

I would look over the entire motor for leaks, then reach down and wiggle the various pulleys find out if there is anything loose, or apt to walk

I would then start it as you have someone listen to the engine

if it sounds like an accessory bearing, lightly squirt some WD40 or other light lubricant at the back side of the pulley, if there is a bad bearing likely this will quiet it, thus pinpointing where your issue is

have someone watch the temp gauge as it runs

ok, after that I would take the next step,,,,if no problem is found,,remove the water pump belt, then start it again

if there is no bearing noise then, this is your problem, the bearing or rotating assembly of the pump

after that, as it is not too bad to get at all for a V6,,you may want to consider a compression test, perhaps there is a head gasket problem

often with aluminum heads,,,not sure what the Toys have,,,(I know from experience)

you may have an intermittent leak with the heads, sometimes will run fine, other times may mysteriously lose antifreeze and it runs hot, still without any white, water type steam smoke out the back

I am thinking water pump though, check that, then post some more

regards, Tim

TStango

Guys,
Thank you for the responses. This really helps me out. I'll let you know what I find.

BOSTON4RUNNER

wish you were more local,,,,where are you in CT???

near Stafford Springs at all?

Regards, Tim

TStango

Hey Tim,
I'm in the south west end of the state, so Stafford Springs is far.

I will finally have time this Saturday morning to look at the 4Runner. So far I bought some Toyota anti-freeze, a thermostat and gasket and I'm trying to locate a new radiator cap.
I'll let you know what I find.

TStango

Well I worked on the 4Runner this morning. Took the skids off to get a better idea of where the noise is coming from. It sounds and looks like the waterpump bearing is going. The pulley has a very slight wobble to it. Kind of weird since the pump only has about 45k miles on it. It was changed 4 years ago when I had the timing belt done at the Toyota dealership. Sucks. I wonder how much of a pain in the ass this is going to be? I ended up changing the thermostat and flushing the antifreeze anyways.

TStango

I'm just going to keep replying to myself because it makes me feel better

After doing some searching here I found a few articles that detail changing the timing belt and waterpump. It it appears the water pump is driven by the timing belt.
The pulley I'm looking at that has the slight wobble to it looks to be the crank pulley. Maybe the slight wobble is normal and it is the WP. Maybe the engine is on the verge of self destruction. WHo knows? The pulley I'm talking about is the big one at the very bottom of this picture. I think it's time to go to the dealership and bend over. I don't want to mess with the timing belt.

SLC97SR5

Some of the posts regarding the crank pulley do indicate a slight amount of movement is OK. The part that indicates water pump failure to me is the squealing of the pump and the dramatic over temp. I've never done a Yota WP but 4X4 Wire has a great write up. I seriously doubt any irrepairaible damage has occured. Keep the updates coming!

TStango

After thinking some more about the wheeling trip I began to realize I would have definitely noticed this noise at the begining of the day immediately after overheating. So it made me think that maybe the two aren't related.
So...... I took some of boston4runner's advice and started to look more closely at the other pulleys. I started the engine and climbed underneath with a large closed end wrench in hand as my stethoscope. Sure enough the bearing of the tensioner pulley for the AC belt is screaming.
I was too quick to assume the overheating and the noise were related.
video:










I started the truck with the AC belt slacked and no more noise.

The only problem now is the adjuster bolt broke. Hopefully the dealer will have these parts when I go tomorrow.

BMWSTOY

It looks like you were getting real close to doing the timing belt - I am just finishing mine and it was not as hard as I thought it was going to be. My Crank came off easily so I was in the clear after that. My noise came from my tensioner breaking off -
Glad you found the culprit prior to taking it to the dealer - always good not to have to do that.

TStango

Yeah it was a huge relief. After reading up some more on the timing belt I was feeling confident and was more willing to take a stab at doing it myself. I still may try it when the time comes. Glad to hear you did ok with yours.