Complicated Head Gasket Problem

[Caper]

I have a 1990 Westerbeke 58 diesel (said to be based on a Perkins 4-154) with 1,370 total hours. The boat had very light use before I bought it 2 years ago, reportedly spending most of its time on the hard in the Caribbean and used only a few weeks a year and not at all during the last 3 years under the prior owner. It had 1,150 hours on it when I bought the boat.

More recently I had the injectors and the injector pump rebuilt due to a small fuel leak in the Bosch designed injector pump (Kiki Fuel Injector Pump 844 D814249, Bosch Pump No. 104640 0005). I had the yard do that work, with a good outside shop doing the injector and pump work.


During the first significant use of the engine it sounded odd, which I initially attributed to the rebuilt injectors and so I keep going for about 10 minutes at 1,500-2,000 rpm. Eventually when I take a look and find that the #2 injector line was loose and leaking fuel. Easy enough to tighten up.

However when we get going again and put it up to 2,200 rpm black smoke and black water is coming out the exhaust. Throttle back to 1,200, and back to the yard after calling it for advice. Engine seems fine with normal temperature, exhaust and oil pressure.

First look at the engine at the yard shows coolant accumulated under the engine and low coolant level in the engine (down about 2 cups).

After about 45 minutes of study with the yard mechanic while tied up to the dock, when under load at 1,200 rpm and up, there is a small coolant leak at the head gasket under the #1 cylinder. One drip every 10-20 seconds. No coolant leak or black smoke absent a load. Idles very smoothly and runs up to 2,200 rpm with no load. Engine oil is normal.

The somewhat embarrassed yard suggests no relationship and advises that the black smoke is due to loss of compression at higher rpm. It advises that a new head gasket is now required at significant expense.

I have had the engine oil analyzed every fall with no problems reported. Engine had run fine and had been very reliable.

Certainly there is a coincidence here and possible the misfiring #2 cylinder unsettled things within the engine. On the other hand a head gasket should stand up to external fuel leaks and misfiring.

This this just a latent problem that popped out by coincidence or is this a result of the loose injector line?

[DeepFrz]

Have you tried torquing down the head bolts? Just a shot...

[donradcliffe]

I don't associate coolant drips with blown head gaskets. I would be looking harder at where the drip was coming from--the #1 cylinder is up where the thermostat and other things are--before I pulled the head.

Some of the other symptoms could be mistiming of the injector pump--did they mark the pump when they took it out so they could line it back up when they installed it??

Not tightening down the #2 injector should not have damaged anything.

I would suggest getting another mechanic.

[Chief Engineer]

There needs to be some serious diagnosis before the "parts changers" take anything apart.....

I hesitate recommending what should be done to diagnose as these guys should know what steps need to be done....If you want to know send me a PM.

And....What Donradcliffe sez.

[Chief Engineer]

Black smoke (soot) is unburned fuel.....do you have an oil sheen on the water?

[Chief Engineer]

Sent you a PM......

[Caper]

Further investigation indicates:

The head gasket coolant leak seems to be unrelated to the black smoke. There is corrosion around where it leaks, suggesting a pre-existing problem. Still this appears to required replacing the head gasket since re-torquing the head bolts did nothing to reduce the problem. Ultimately this seems to be a problem that will not get better with time, but it seems like the boat can be uses as long as I keep an eye on the coolant. Ultimately however - Ouch!

The injector shop suggests that even though the pump was indexed so that it lined up when re-installed, now the pump bolts should be loosened and turned clockwise a bit to stop the black smoke. This is a Perkins authorized shop. Other sources scoff at that suggestion.

I am wondering if Westerbeke tweaked the injector pump specs a bit so that the standard Diesel Kiki injector pump specs do not work. Ultimately I may just send it back to Hansen to be sure.

As costs mount I will have 30% of the cost of a repower spent

[Chief Engineer]

Did they pressure test the block?

Doesn't sound like it.

Did they check the pressure of the coolant system while running?

Doesn't sound like it.

Did they do a compression test?

Doesn't sound like it

Doesn't appear to be any diagnosing going on....just guessing.

Sorry if this appears abrupt....but there has to be some actions performed to acertain the problem