Can Someone Positively Identify This Coolant Leak? (1 Viewer)

[ewillis]

I'm in the middle of overhauling my coolant system in anticipation of the hot summer ahead. While fixing the PHH (now affectionately known as MFPHH by me) I noticed a bit of coolant buildup above/on top of the PHH. It looks like a head bolt the coolant is sitting on. My initial thought was that it may be one of the bypass hoses under the throttle body. I wedged a maglite pointing straight at it from underneath, near the PHH and inspected from the top.

It really doesn't appear to be coming from the area of the heater line under the TB. Could this have been a small drip from the heater valve? I just replaced that too and it looked good. Is it possibly an external HG leak? Kinda freaking out a bit...any help appreciated!

 

[baldilocks]

I'm not able to make out what you are talking about. Are you referring to the crud built up just forward of the PHH? It is entirely possible to have an external HG leak.

 

[ewillis]

I'm not able to make out what you are talking about. Are you referring to the crud built up just forward of the PHH? It is entirely possible to have an external HG leak.

Yeah the reddish crud to the left of the PHH in the pic. Hard to get a good picture in that space. It's under the intake plenum and impossible to spot from the topside. I'm just not 100% positive where the heater hose under the TB terminates.

 

[baldilocks]

The TB hose terminates into the head but forward or the PHH. Probably not the problem because when that hose leaks you see it on the ground immediately.
It looks like old crud. I would just run it and keep an eye on it.

 

[richardlillard1]

So...is it consuming fluid? I would want to know the answer to that before any concern about crud on the block.

 

[ewillis]

So...is it consuming fluid? I would want to know the answer to that before any concern about crud on the block.

I've noticed a slight drop in the reservoir. I first looked closely at the heater control valve and could see where it looked as if there may have been a small drip. There was what appeared to be small amounts of burned fluid directly underneath, but hard to tell for sure. Just replaced the heater valve and it looked perfect. Sent for Blackstone a few months ago and this was part of the response, so no internal HG for sure.

ERIC: Only a slightly low viscosity kept the first sample from your Land Cruiser from being perfect. And the viscosity is not a problem - it's obvious this oil worked well for you while it was in service. Universal averages show typical wear from this type of engine after 4,700 miles.

 

[richardlillard1]

I've noticed a slight drop in the reservoir. I first looked closely at the heater control valve and could see where it looked as if there may have been a small drip. There was what appeared to be small amounts of burned fluid directly underneath, but hard to tell for sure. Just replaced the heater valve and it looked perfect. Sent for Blackstone a few months ago and this was part of the response, so no internal HG for sure.

ERIC: Only a slightly low viscosity kept the first sample from your Land Cruiser from being perfect. And the viscosity is not a problem - it's obvious this oil worked well for you while it was in service. Universal averages show typical wear from this type of engine after 4,700 miles.

Your coolant system is working as designed. It's supposed to pull coolant from the reservoir. It's a pressurized system, so a failure in the system would cause loss of suction; the reservoir wouldn't drop.

Unless the rad is low?

 

[ewillis]

Your coolant system is working as designed. It's supposed to pull coolant from the reservoir. It's a pressurized system, so a failure in the system would cause loss of suction; the reservoir wouldn't drop.

Unless the rad is low?

No...rad isn't low. Everything's fine other than a slight drop in coolant level in the overflow bottle. Replacing all hoses, radiator, T-stat, fan clutch, etc. as PM. While changing the PHH, I noticed the buildup above...just trying to figure out where it's coming from. I think I'll have to pull the throttle body and check/replace that hose. If it's not that, it has to be coming from the head as a drip from the heater valve seems unlikely.

 

[richardlillard1]

So it isn't losing coolant, but you want to chase something down?

 

[Qball]

That could be the number 1 bypass hose which caused me tons of headach. I paid someone to change it because it's that much of PIA.