OT- Diesel box truck again...still overheating, but this time not due to water leak..

Milacron · Apr 7, 2014

Now not leaking a drop, but the temp needle gradually climbs such that 20 miles is about the limit before I need to stop. Some may recall I had a leak between the timing cover and the block, which would have been a monumental PITA to fix via proper means, and therefore I took a chance on Bars Leak. The concoction did stop the leak, but I'm guessing it also stopped up something else.

So, the question is might a high pressure flush, dislodge the clog ? Could be a new pump impeller and/or themostat might help but almost certainly the main issue is a clog somewhere in the system caused by the Bars Leak. I say this because when it leaked it did not overheat as long as it had water...only when the water level got low did it begin to overheat. Now it has plenty of water but apparently is not circulating everywhere it needs to go.

Thoughts ?

1996 Hino FB series with turbo diesel, 360,000 miles, runs perfect except for overheating.

Vernon Tuck · Apr 7, 2014

Is there any difference between running empty and loaded?

While 360K is not stratospherically high mileage - still - the truck is no spring chicken.

The implication is that the compression ratio might be so low that she struggles on the grades and runs warm. Some relatively inexpensive diagnostics by a competent diesel shop should get to the bottom of the matter metinks.

V

scojen · Apr 7, 2014

Don,
You could try taking the thermostat out and seeing if it overheats or just replace it with a new one if it is not the thermostat then the water pump is the next logical choice to investigate.

aspp · Apr 7, 2014

360000 miles is nothing for that motor. Take it to a good shop, you will need to have the radiator rodded out and the leak fixed correctly. Tell them you used the Bars Leak. Take some vasoline, you might have fkd yourself with the Bars Leak. Without a S/N off the motor I don't know which head or turbo it has, but if it is the small port head you will have plugged it up solid with that junk. Be happy you were watching the gauges and didn't cook the motor.
Those leak stop products are to get you off the side of freeway and to a shop, not to "fix" anything. 9/10 they cause more issues in a diesel than they solve.

allloutmx · Apr 7, 2014

any chance its vapor locked? try running the truck with the cap off for 5-10 min...top off the radiator and try running it with the cap back on..

Milacron · Apr 7, 2014

Vernon Tuck said:
Is there any difference between running empty and loaded?

While 360K is not stratospherically high mileage - still - the truck is no spring chicken.

The implication is that the compression ratio might be so low that she struggles on the grades and runs warm. Some relatively inexpensive diagnostics by a competent diesel shop should get to the bottom of the matter metinks.

V

The overheating is with the truck empty on flat grade and air conditioning not on. The Bars Leak thing was done months ago but last week was the first time I have driven the truck since then. Naturally I need the truck this month rather badly...but only need to go 40 miles each way (with hours between each way so it would have time to cool off) ...if I could just go 40 miles it would be ok for now, but don't think I can make it even 40 miles. :angry:

michiganbuck · Apr 7, 2014

You could have a high temp head gasket leak that would not show in a normal head gasket test.
Just enough hot gases going in to make things hot. (I had that on a gas ford engine)
You could recheck head torque but that will not fix a blown head gasket.
If having a trans cooler a trans slipping and getting hot.
50 % or so radiator efficiency.
I think I might replace the radiator for a first chance try.

*This should have done:
Themostat should have been first check/ water pump belt slip second check/ hose inside collapse third check/ water pump pressure perhaps fourth check.

jCandlish · Apr 7, 2014

Milacron said:
runs perfect except for overheating.

What a saga.

Anyone following your Hino posts will concur ... the Hino is done.

A stitch in time was by-passed with a quick-fix one time too many.

kenh · Apr 7, 2014

Is it down on power? a partially plugged exhaust would cause overheating .As would low boost.

ewlsey · Apr 7, 2014

I doubt any diesel engine with 360,000 on it is "done". It just needs some work. I'd guess you need a new radiator core, head gasket, and that leak in the front cover fixed. That's going to cost a few thousand dollars, so it may not be worth fixing, but it's not done for if you are willing to fix it.

jCandlish · Apr 7, 2014

ewlsey said:
so it may not be worth fixing

may?

<jbc> said:
Especially 'cause for modern alloy engines its not just antifreeze. Coolants are supposed to have anti-corrosive properties too. Milacron has mentioned a couple of times how VW has the worst service record. Allot of that is due to hicksticks using yesterday's antifreeze and un-maintaining the motor. VW was the first manufacturer of scope to require corrosion inhibiting coolant in their cars.

There is a reason that coolant is dyed green, red, orange, yellow, or blue.

If Milacron has run the Hino for a season with straight tap water the engine and its accessories are probably done.

.

and

Milacron said:
Until about a month ago the leak was slow enough that there probably was some antifreeze in the system...not enough, but some. But for a month I would say it probably was pure tap water sure enough. No ill effects evident yet but we'll see. At 360,000 miles will be hard to say if anything does need replacement if it was due to lack of antifreeze or just miles and age.

.

Milacron · Apr 7, 2014

kenh said:
Is it down on power? a partially plugged exhaust would cause overheating .As would low boost.

No, the irony is it seemed to be running really nicely..plenty of power and smooth as silk... just overheating.

jCandlish · Apr 7, 2014

Milacron said:
No, the irony is it seemed to be running really nicely..plenty of power and smooth as silk... just overheating.

Just overheating? Is the liftgate fixed?

Milacron said:
Equipment malfunction. Try and imagine this senario. Small box truck with 7 foot long AHT ligfgate like below. Liftgate capacity 3,400 lbs. I pallet jack small Mikron gear hob machine that is well banded to pallet, weights about 1,800 lbs from inside box to the open/level lifegate. I don't go much beyond the transition of truck box to liftgate since the liftgate capacity obviously declines the further out you go and my forklift forks are long enough to grab it that far back anyway.

So, I lower the pallet jack so the pallet is resting on the liftgate and get ready to remove the pallet, get off the truck and get the forklift and then to my amazement start hearing the sickening beeping noise that means the liftgate is overloaded and sinking ! And I don't mean sinking as in going straight down, but sinking as in going from level to ever increasing downward angle !

Milacron · Apr 7, 2014

<jbc> said:
Just overheating? Is the liftgate fixed?

No but I could easily fix that if I took the time to do so. AHT sells a seal kit at reasonable price, just never got around to installing such. Even without fix it still works well enough as long as I don't get overconfident with it like I did during the incident you quoted.

RE "ruining the engine" running tap water, it never had just tap water but no doubt has run for over a year low on coolant...so there could be some premature wear or blockage due to that sure enough. But it wouldn't just happen to go from running at perfect temp until water level gets low to running warm to hot even with full radiator due to internal corrosion issues that suddenly. Could happen, but unlikely it would happen that sudden and that cooincidental to the Bars Leak.

Joe Rogers · Apr 7, 2014

Used to service a brand that had numerous cooling system issues and the manufacturers fix was to install coolant sealant tabs.(Solid Bars Leaks substitute)
Vehicles engines never had cooling system issues until several applications due to overzealous treatment occured. How much Bars Leaks did you install?
One application should not have clogged anything to the point of overheating IMHO. Several doses...all bets are off. Radiator cap pressure relief tested? 50/50
mix of coolant installed? Belts tight? Lots of little problems could contribute. My experience with diesels is that they run cool though so sumpin ain't right.
Joe

WizardOfBoz · Apr 7, 2014

My car (740il) started overheating. About 185K miles. Had to replace the water pump - the impeller wasn't being driven positively, apparently. Can't tell from the thread: was your water pump replaced?

Milacron · Apr 7, 2014

Joe Rogers said:
Used to service a brand that had numerous cooling system issues and the manufacturers fix was to install coolant sealant tabs.(Solid Bars Leaks substitute)
Vehicles engines never had cooling system issues until several applications due to overzealous treatment occured. How much Bars Leaks did you install?
One application should not have clogged anything to the point of overheating IMHO. Several doses...all bets are off. Radiator cap pressure relief tested? 50/50
mix of coolant installed? Belts tight? Lots of little problems could contribute. My experience with diesels is that they run cool though so sumpin ain't right.
Joe

One application of BL...plus it was not the "heavy duty" large leak version that requires pure tap water but was the "small leak" version that works with coolant still in the mix.

Fabworks · Apr 7, 2014

Many years ago I ran a snocat with a turbo diesel engine that had an overheating problem. The guys in the shop eventually attributed the problem to a clogged or obstructed intake.... I remember they replace the air cleaner. The engine just wasn't getting enough air. Usually diesels run much cooler that gas engines.

Milacron · Apr 7, 2014

bosleyjr said:
My car (740il) started overheating. About 185K miles. Had to replace the water pump - the impeller wasn't being driven positively, apparently. Can't tell from the thread: was your water pump replaced?

Never by me, but most likely it has been in the past as Ryder serviced the truck up to about 345,000 miles, when I bought it.

matt_isserstedt · Apr 7, 2014

When you think about the cooling system...there's a pump, a radiator, an engine with water passages and a thermostat.

If the pump is pumping and it isn't restricted on the inlet side (that leads to cavitation/boiling) then you have a blockage somewhere, it could be in the water passages, the radiator, or the tstat no longer responds.

Bottom line is its time to open stuff up and see what's wrong. You might get away with doing some checks with a garden hose pouring into various hoses pulled off the radiator to visualize flow, but the antifreeze you extract needs to be contained and not just dumped.

You can also check to see if you have heat in the cab. More or less the heater core is also a very small radiator, and so if there is limited waterflow there will be limited heat output.

OT- Diesel box truck again...still overheating, but this time not due to water leak..

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