Water pump or head gasket?

**InTranzit** · 06.28.2012

Originally Posted by ajmb

My husband has me asking a question since he is on the road.

My husband was recently talking to you, and he just had the PDI stage 1 done by Joe on his peterbilt 379 Cat C 15 BXS. On the first trip he was blown away by how everything worked.
On this trip something has gone wrong.
he took a load from Toronto heading for Vancouver through north Canada, it was tri axle liquid tanker. The water temp started to get really hot resting at 215 and overheating on any grade.
The fan is on at all times, when he pulls over it will cool the rad off.
There is no leak from the water pump,
Coolant is not coming out the overflow, there is no visable signs of coolant anywhere but yet losing quarts of it.
Made it Calgary and in the morning the engine locked, not sure but wonder if fluid could be on the pistons? My husband called Joe, and Joe said probably a thermostat, and cat and another shop and they all said cracked head or gasket.
Checked rad and does not appear to be blocked.

Any thoughts?

Not an easy thing to diagnose!

By employing the "process of elimination" tactic with close observation of the symptoms we might reach some coclusion that would reflect, as close as possible, where the problem might be.

If you think that the water pump could be the problem, then you'd expect the engine to overheat rapidly and stay at high temperatures even when not under load. Not in all instancess is the possibility of external coolant leaks when there's pump faliour. That's why you want to do another test that would prove the absence of coolant flow. Turn the cab heater blower on and set the controls for heat. If there's no heat comming through the vents, than it is a logical conclusion that the coolant flow has stopped.

If there's cillinder lining faliour due to poor coolant PH levels maintenance or material structure faliour like a crack, also a cylinder head and/or cylinder head gasket failure that allows transfer between cylinder, oil and coolant cavities you old expect pressure buildup in the coolant expansion tank with or without oil and coolant fluid mixtures while the engine is overheating.

If there's engine overheating with no pressure buildup in the expansion tank:

1- good cab heating, no oil and coolant mixture. Causes: thermostats locked in closed position(very rare occurance for 2 thermo's to lock at the same time) or obstruction created by solid materials in the radiator.

2- good cab heating, but oil and coolant mixture. Causes: failure of the cylinder head and/or cylinder gasket that allows transfer of fluids. Not in all cases a reason for overheating. In fact, very rare.
Also, a failure of the oil to coolant heat transfer core would cause an oil and coolant mixture, all though I've never seen an engine overheat excessively due to this kind of situation.

If there's oil loss but no visible mixture in the coolant, the oil lose it's not the cause of the engine overheating, but as a consequence of the engine overheating in the first place. If the engine overheats excessively the temperament in the piston rings is lost, thus the engine starts to use oil in excess. Also an excess of "blow by" gasses can be observed and also loss of power.

Aparently the man kept on driving that truck with the engine overheating till a compound of faliours has occurred. In this case, the only solution is to perform a complete disassembly of that engine and replace all components that show structural faliour.
If the engine locked, then there's no other solution then a complete engine overhaul.

I hope that this helps,

Good luck!

**Gear head** · 06.28.2012

Its hydrolocked coolant on top of cylinder or cylinders. my also be injector cup o-ring failed drained on top of piston from pressure of coolant. Pull injector out of coolant filled cylinder pressurize watch where cup meets head.

**InTranzit** · 06.28.2012

Originally Posted by Gear head

Its hydrolocked coolant on top of cylinder or cylinders. my also be injector cup o-ring failed drained on top of piston from pressure of coolant. Pull injector out of coolant filled cylinder pressurize watch where cup meets head.

Yea, not sure what thy mean by "engine locked"......if locked as in seized or will crank but not start.
If the thing will crank but not start, you might be right. But if the engine is seized, well than, there's more damage than the injector cups.
??? Coolant in the cylinder cavity will drain overnight or in a day or so and will allow the engine to crank up, but will not start.
Also the cylinders with open exhaust valves will purge the coolant out, only the one on compression mode will seize the engine. Should see coolant in the exhaust side of things too.
If that much coolant in the cylinder, well than, it should show up in the oil pan. Oil should be heavily contaminated with coolant fluid......and levels in the oil pan should go up not down. Remember?? Excessive oil consumption???

Think man!

Think!

**superhauler** · 06.28.2012

Originally Posted by InTranzit

Yea, not sure what thy mean by "engine locked"......if locked as in seized or will crank but not start.
If the thing will crank but not start, you might be right. But if the engine is seized, well than, there's more damage than the injector cups.
??? Coolant in the cylinder cavity will drain overnight or in a day or so and will allow the engine to crank up, but will not start.
Also the cylinders with open exhaust valves will purge the coolant out, only the one on compression mode will seize the engine. Should see coolant in the exhaust side of things too.
If that much coolant in the cylinder, well than, it should show up in the oil pan. Oil should be heavily contaminated with coolant fluid......and levels in the oil pan should go up not down. Remember?? Excessive oil consumption???

Think man!

Think!

not always, my headgasket went and the cylinder stayed filled with antifreeze until i tore it down. it's not a good idea to try and turn the engine over, you can bend a rod or worse. yes the oil pan would be filled with antifreeze if bad enough.

**InTranzit** · 06.29.2012

Originally Posted by superhauler

not always, my headgasket went and the cylinder stayed filled with antifreeze until i tore it down. it's not a good idea to try and turn the engine over, you can bend a rod or worse. yes the oil pan would be filled with antifreeze if bad enough.

Anything is possible! I guess ya gotta tare it down and find out what went wrong.

**dannythetrucker** · 06.29.2012

Originally Posted by InTranzit

2- good cab heating, but oil and coolant mixture. Causes: failure of the cylinder head and/or cylinder gasket that allows transfer of fluids. Not in all cases a reason for overheating. In fact, very rare.
Also, a failure of the oil to coolant heat transfer core would cause an oil and coolant mixture, all though I've never seen an engine overheat excessively due to this kind of situation.

sure it overheats. 1. oil/water gunk in a radiator doesn't cool or flow as well as coolant. 2. when the oil cooler fails, you will loose fluid level in the coolant system as well as provide inadequate lubricant. I'm not gonna tell you how I know this, but let's just say the underside of a 2008 KW hood and engine covered with gunky grey stuff is pretty ugly !!

**InTranzit** · 06.29.2012

Originally Posted by dannythetrucker

sure it overheats. 1. oil/water gunk in a radiator doesn't cool or flow as well as coolant. 2. when the oil cooler fails, you will loose fluid level in the coolant system as well as provide inadequate lubricant. I'm not gonna tell you how I know this, but let's just say the underside of a 2008 KW hood and engine covered with gunky grey stuff is pretty ugly !!

Sure mate, you've got it right!
The thing is that any oil and coolat fluid mixtures in the engine assembly should be detected well before everything turns into the ugly grey gunky mass and experience engine excessive overheating. Regular maintenance and daily fluid level checks will indicate any presence of this kind of fluid exchange between the cooling and lube systems. Abserving an oil film in the coolant expansion tank and/or the oil forming a yelow-greyish foam visible on the dipstick would indicate that mixtures of oil and coolant has occurred(at the point where it's become visible). If you're running an oil analisis test you can detect such mixtures even before it becomes visible. If you wait till the engine gunck's up and overheats, by then it could be too late for an easy and quick fix, also you may have multiple compounded failures in the engine that are created as a consequence of a delayed repair of the initial problem.

The truck driver job doesn't involve only the warming and enriching the driver's seat with natural methane gases while holding on that steering wheel!

**ajmb** · 07.04.2012

Well, we are not sure what to think now. Cat is now saying that it's not the head. They said the rad was so blocked and not circulating. They are going to redo the rad. They also said he had a massive coolant leak which is strange because wouldn't we have noticed it? As far as the truck not starting they say that he has a weak starter and his batteries are shot. If that is the case then something is drawing on the batteries pretty bad since they are fairly new batteries because the truck was having battery problems before. Not sure how much we trust cat, and what they are saying, but they did put it on the dyno and said that's what it was. They also said he needed thermostats. Does that sound believable?

**2bit** · 07.04.2012

I guess at this point I'd be saying take me out in the shop and prove some of this to me. Load test the batteries(make sure they"re unhooked from each other) and show me the current draw on the starter. How did they determine the radiator is blocked? There is an aluminum plate on the water pump that wears with age. With lots of miles the gap between the plate and the fins can open enough that the coolant recirculates in the pump instead of being pushed through the radiator. Never let them change the pump without also putting on the plate. How many miles on the truck? Could be combo rad,thermostats, pump. That doesn't explain the engine being "locked" though. If they can't won't explain what's going on and what they did to come to that conclusion, you need to go elsewhere if possible, or risk throwing parts at it that aren't needed. An honest shop can explain what they've done so you understand. And what's getting in the radiator to plug it internally? This needs to be found and fixed.