Coolant residue on intake manifold

[willywebster]

Good catch on the water pump, they start leaking before they fail outright. Do you have a lot of miles on that rig though? It looks like it has seen better days with all those leaks.

No, it's not possible for a water pump leak to splash up top. Your belt would be slipping and squealing like mad if it was wet with coolant anyway. Water pump leak is unrelated to your intake valley leak.

All seals & gaskets are one-time use. Replace each gasket you have to separate (upper plenum, lower plenum, etc) and yes, make sure you replace all o-rings on the injectors. The o-rings are cheap and you don't want to be doing it all a second time because instead of coolant, fuel is filling up the intake valley!

im pretty glad i caught the water pump before it popped, its exactly 90km since the timing belt was last change so cheers to recomended service intervals (however im not sure if just the timing belt was done and the water pump was left as the pump and tensioner pully were in rough shape)

my 4 runners got 280kms on it ive only owned it for about a year and dont know how well it was maintained.. however it runs great.. and as for the leaks i dont reacall my motor having any coolant laying around, it def wasnt dripping.. it did have the oil deposits from the valve covers leaking but wasnt loosing anything noticeable on the dipstick.. however im suspicious that a few months back i had a shop do a pressure test on the rad (shop said it was all good) and im thinking that the pressure test may explain the amont of coolant laying around

anyway thats where im at now, ive got some serious cleaning to do and ill be sure to change all the gaskets as i go here and ill report back

thanks for all the input its a huge help

 

[gamefreakgc]

Seems like you know your way around an engine so you'll do great. The 5VZ-FE's are very forgiving on maintenance so I'm sure it has a lot of life left, plus they are pretty easy to work on with lots of space in the engine bay.

 

[BostonJon]

Looks to me 100% like a bad intake manifold gasket. I had the same leak up top. Mine was dripping down the back and not the front, but I first noticed it in the same spot you did.

 

[willywebster]

well after a lot of cleaning, finally got the intake off and it looks to be excatly like you guys said the seals around the coolant channels were degraded and leaking.. now just gotta wait on parts!

if anyone is doing their intake manifold gasket i wanted to give a heads up that the 4 studs on the intake manifold (i attached a picture) have a washer that likes to sticks to the manifold and may fall off when you pull the intake off.. i almost had one fall in the head! so make sure you pop them off when u remove the nut.

 

[BostonJon]

Glad you found the culprit. Probably worth doing the knock sensor wiring harness and upper/lower plenum gaskets while you’re in there

Edit: and the fuel injector o rings

Edit again: below is a link to my post on this topic. Includes some pictures of the gnarly IM gasket

Help - coolant in the valley - why?

 

[willywebster]

Glad you found the culprit. Probably worth doing the knock sensor wiring harness and upper/lower plenum gaskets while you’re in there

Edit: and the fuel injector o rings

Edit again: below is a link to my post on this topic. Includes some pictures of the gnarly IM gasket

Help - coolant in the valley - why?

thanks man, ya im waiting on the intake gasket injector orings and knock sensor harness and already have the plenum gaskets so hopefully there wont be anymore surprises and i can get back on the road soon. it woulda been a nightmare sourcing parts and appropriate steps wihout your post!!

 

[2owner4runner]

I am also having coolant loss

Does anyone know if it is possible to have good compression in all 6 cylinders but still have water in some of them? Thanks

 

[Bad Luck]

Does anyone know if it is possible to have good compression in all 6 cylinders but still have water in some of them? Thanks

99.99999999999999% of the time not possible. If there is a way for coolant to get into the cylinder then there is a way for pressurized air to get out. Only exception I can think of is a small amount of coolant getting into the cylinders somehow during the intake stroke, but I would imagine something like that would allow too much coolant to accumulate when the motor is off and the cooling system is pressurized from normal operation and hydrolock the motor at the next start.

 

[brillo_76]

99.99999999999999% of the time not possible. If there is a way for coolant to get into the cylinder then there is a way for pressurized air to get out. Only exception I can think of is a small amount of coolant getting into the cylinders somehow during the intake stroke, but I would imagine something like that would allow too much coolant to accumulate when the motor is off and the cooling system is pressurized from normal operation and hydrolock the motor at the next start.

Excellent explanation Bad Luck.









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[2owner4runner]

thanks for the reply

not looking forward to the next step

 

[19963.4lsr5]

not looking forward to the next step

The only sure fire way is to park it and let it cool down and pull the spark plugs and put a borescope in each hole and look for antifreeze.

I had an eroded cylinder wall that would leak antifreeze. If the piston was down it fill the dish of the piston. If it was up leaked into the oil pan. Only giveaway was the ruff start and thick white vapor out the exhaust for about 15 seconds after startup, and a P0420 code that kept coming and going.


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[PNW 4Runner]

I’ve discovered the same issue on my 97’. Both gaskets failed at coolant ports. Gaskets rusted, now there’s rust accumulation/platting in the coolant channels and probably heater core and rad. Any suggestions on how to flush out the rust?

 

[spartacus]

I’ve discovered the same issue on my 97’. Both gaskets failed at coolant ports. Gaskets rusted, now there’s rust accumulation/platting in the coolant channels and probably heater core and rad. Any suggestions on how to flush out the rust?

This might help
Filthy cooling system

 

[PNW 4Runner]

This might help
Filthy cooling system

Thank you.