Elusive Coolant Leak

[CruisinGA]

Recently replaced faulty radiater with OEM about a month ago. Also replaced all hoses while I was at it.

Subsquently I had no coolant leak, fluid level remained stable for at least several weeks.

Two days ago the truck began to overheat from a lack of coolant.

There is no steam rising in the engine bay upon shutdown, and no coolant drip onto the ground. Oil is fine.

Any known possibilites I should be checking out? Seems like it would have to be a very hot location where the coolant is steaming off as it is leaking.

Thanks.

 

[Andrewsreef]

I am no expert but did you check the thermostat to make sure it is not sticking closed? Definatley do not want to overheat as that could cause serious engine damage including the headgasket/warp the head.

Good luck.

Andrew

 

[OGBeno]

Hey Bailey--

How back the heater valve hoses in the rear of the engine compartment??

I had a small cut in the hose going into the pipe that feeds into the PHH, and it was slowly leaking and burning off on the backside of the engine and I didn't see a thing until I noticed the overflow container was getting lower and lower.

I replaced that for $5 at Napa with the Green and it's been fine since.

Also, is the PHH ok? I assume you've done this? If not, maybe there's the possibility it's leaking there?

Good luck dude.
best.
-onur
Akron, OH

 

[turbocruiser]

Hey Cruisin, i kinda feel weird with suggesting something to someone several s past myself in mechanical experience, but with that in mind, you did not mention anything about checking the rear heater hoses; they could be weeping pretty well and only dripping while yer driving. Of course it would be weird to have the heater valve set to open in GA so who knows on that one. Could also be front heater core hoses or core itself but again, it would be weird to even have the heater valve open I would think (except at night maybe?, not sure what GA weather is right now). Also, if it were front heater core or hoses, you'd prolly smell some coolant inside yer rig. Then again, if you are running a little heat at night and there is a weep with the rear hoses, you'd prolly never smell it and never see it by the time daylight came, the heater valve was shut, and you were overheating from lack of coolant.

You mentioned you changed all the hoses, did that include the bypass lines up by the throttle body? Perhaps a small leak there would drop down onto the engine and slowly evaporate while driving but not enough to "steam the engine bay". Another suggestion is super loose radiator overflow tank cap - I had one and noticed alota leaking up there - got a new one from Dan the man and my coolant level stays exactly steady. I'd check the bypass lines and the overflow tank just to rule them out.

Lastly, the dreaded HG. Your oil is fine but perhaps its leaking inside just enough to exit via the exhuast and not so much as to get past the rings. I hope not, but its possible.

Okay, that's my best shot, hope its an easy find and an easy fix.

 

[bigbrowndog]

Try and establish your water pump is working and not leaking. Fill the radiator then run the engine and top up.Bring it to operating temperature and make sure the thermostat has opened.Should see the water passing through.Make sure its completely full,no air locks in the head or block.Open the heater valve and make sure the heater is full and circulatlng also. Then chech your radiator cap to make sure it is sealing ok.Pehaps check your belt tension.Excessive bubbling in the radiator could be caused from air in the system or a blown head gasket. Might pay to get a pressure test done.

 

[John E Davies]

You really need to either buy or rent a cooling system test kit. I have a Stant kit that came from NAPA - with the 2 Toyota adaptors it was around $100. I use it a lot. I have located really hard to find nuisance leaks with the tester and it is good for testing the cap also. It's very well made and comes with a nice case and instructions.

You can pump up the system and crawl around while watching for leaks. Sometimes you can actually hear the leak as a quiet hissing. It sure beats screwing around for days over a hot engine and not getting antwhere.

http://www.costplustools.com/store-categories-Radiator-Testers_7958.html

http://www.costplustools.com/store-...Stant-Radiator-Pressure-Tester-Kit_39313.html

John

 

[bigbrowndog]

CrusinGa, may have missed your reply , did you sus out your overheating problem??? hope so.

 

[OGBeno]

CrusinGa, may have missed your reply , did you sus out your overheating problem??? hope so.

If I recall correctly, his PHH went kaput on him. I think he waited too long to do the PM on it. I know he recently put a new radiator in as well.

-onur
Akron, oH

 

[BrianDale]

I just had the same problem last week. I kept smelling the maple syrup smell and filling the resevoir. I found the top of the engine hose, the one running over the top on the passenger side, had a loose screw, holding the hose tight. The coolant would run down on to the manifold and burn off, leaving almost no sign, If you lay under it look for the run down marks on the hot spots. It drove me nuts until i came home at 3:00am and crawled under it and found the spot. Never better, and sweet jesus it was free. God Speed...............