Looking for help on My Hino 338

grape grower · Feb 28, 2015

Yesterday I picked up my 338 2009 Hino with the Allison automatic transmission. I had a water tank and pump installed to keep the mites from eating too many grape leaves.

The install included shortening the frame, removing the left side fuel tank and lowering the ratio of the differential.

Driving down the road with a broad smile on my face and the feeling of accomplishment, I had wanted a water truck for years.

Suddenly the truck started to accelerate, an uncontrollable acceleration. I jammed the brake pedal as hard as possible, there was some deceleration but in the next second the engine exploded. I glanced in the mirror and the only thing i saw was a giant cloud of blue smoke and the sound of metal against metal.

I have an appointment with our local Hino dealer to try and find what went wrong but any idea's you have, I would appriciate.

Thank you

tknight · Feb 28, 2015

sounds just like the turbo blew out and filled the charge air cooler with oil spray causing the engine to run away out of control. good luck, hate being bearer of expensive news, but it wont be cheap, keep us posted

Dynamite 1 · Feb 28, 2015

I would agree with that diagnosis.

tknight · Feb 28, 2015

I wonder if the sell knew it was going bad and just forgot to tell Ya!

greasytshirt · Mar 1, 2015

Were the injectors recently replaced, or did it have a valve adjustment done?

There is a metal line under the valve cover that attaches to the the top of each injector. This channels fuel return to the outside of the engine.

This line is rather delicate. If it is put on properly, it never leaks. If it is kinked or bent, or reused, or if the banjo bolts are not tightened properly, or if any of the seals leak, or if the one-time-use banjo bolt is tightened more than one time, fuel can leak into the oil.

With enough fuel dilution, the engine oil level rises. If it rises high enough, the crankshaft whips it into a froth, it enters the crankcase breather, gets pulled into the intake side of the turbo, then things get very exciting as a nearly unstoppable chain reaction soon follows.

If someone was in there recently adjusting the valves (and especially the crossheads), the line is easily damaged.

It needs to be towed to a shop, the valve cover removed, the EXTERNAL fuel return line removed, then about 30 psi of regulated air should be put into the hole connected to the internal return line. Carefully check for leaks. If there is a leak, then whoever was banging around upstairs the last time is the person responsible. An oil sample, if any is left, should be taken and sent out and checked for fuel dilution. If human error is the culprit, then some human other than yourself needs to find you an engine.

This scenario happens somewhat frequently. The line never leaks until someone fouls it up.
Those that don't own an inch-pound torque wrench, reuse the line, reuse the seal washers, kink or bend the line, or reuse the one-time use banjo are the ones that foul these up.

All Hinos built before 2008 are much less susceptible to this because they'll just puke the excess oil/fuel mixture out of the road tube.

If internal fuel leakage is not the culprit, then it's probably the turbo.

grape grower · Mar 1, 2015

grape grower said:
Yesterday I picked up my 338 2009 Hino with the Allison automatic transmission. I had a water tank and pump installed to keep the mites from eating too many grape leaves.

The install included shortening the frame, removing the left side fuel tank and lowering the ratio of the differential.

Driving down the road with a broad smile on my face and the feeling of accomplishment, I had wanted a water truck for years.

Suddenly the truck started to accelerate, an uncontrollable acceleration. I jammed the brake pedal as hard as possible, there was some deceleration but in the next second the engine exploded. I glanced in the mirror and the only thing i saw was a giant cloud of blue smoke and the sound of metal against metal.

I have an appointment with our local Hino dealer to try and find what went wrong but any idea's you have, I would appreciate.

Thank you

I appreciate everyone's input. Thank You, I purchased the truck from Penske in Clackamas, OR. Prior to making the purchase decision I pulled an (engine)oil sample and sent it off to Cat for analysis, there was no contamination and all metal levels were within acceptable tolerance. I took the truck to the local Hino repair center, they downloaded all of the codes, did not find any serious problems. I have the repair and maintenance records from Penske and there was replacement of injectors and turbo, I will check the fuel line under the valve cover. Thank You

greasytshirt · Mar 1, 2015

I would argue that the valve cover be removed and line checked for leaks by penske, in your presence. But first, pull the metal elbow off of the turbo air inlet. Is the compressor wheel intact, or did it disintegrate and shear off of the shaft? If so, no reason to dig any deeper.

greasytshirt · Mar 1, 2015

Also, depending on when the turbo was replaced(if it was the cause of this), it might possibly have some parts warranty left. If it does, there's a possibility of some good-will warranty on incidental damages. Get both Penske and the dealer who did the repairs involved, and get the dealer's TSM involved too. He's the guy that has the power, to some degree, to approve good-will repairs of this nature.