Update on Columbia/Mercedes 4000 blown head gasket

[ichudov]

My Mercedes 4000 engine from my 2009 Freightliner Columbia blew a head gasket. Dealer asked for enormous money.

We found someone who works fixing these engines for a living. This guy said right on the phone, "probably a head bolt broke". He came to look, confirmed that it was likely, and quoted $800 in labor plus I buy all parts. I bought parts for $1,500. This guy and a helper fixed it in one day and one additional evening.

The truck starts and drives now and I will try to use it today for something. I am kind of happy with this outcome, but he warned me that this is a specific problem with these engines and more heads (it has six separate heads) may break later down the road.

   

[Chamberpains]

Sounds like I'd be saving some cash and in the mean time figuring out what exactly causes these engines to break head bolts. Then over engineering a more long term fix for all 6 heads at once. To hell with breaking down at any given time.

Is it poor grade of bolt? Improper torquing? To much cylinder pressure?

[Volvo8873]

I think there is 5 headbolts per cylinder. 30 headbolts holding down individual cylinders along with a high compression ratio might have something to do with it.

[dhirocz]

...maybe the bolts are made in China?

Seriously. Got a picture of the broken ends of the bolt?

If that were the case, I'd call up ARP and get them to spec a set of head studs for you.

[Waterloo]

(03-27-2018 )dhirocz Wrote:  ...maybe the bolts are made in China?

Seriously. Got a picture of the broken ends of the bolt?

If that were the case, I'd call up ARP and get them to spec a set of head studs for you.

OEM baby! The head bolts for my ISX were what, $30+ ea? They were not cheap, but they were the correct bolts, hopefully to spec.

[ichudov]

(03-27-2018 )dhirocz Wrote:  ...maybe the bolts are made in China?

Seriously. Got a picture of the broken ends of the bolt?

If that were the case, I'd call up ARP and get them to spec a set of head studs for you.

The picture of the ends of the broken bolt was attached to my original post. Please take a look.

It looks like the bolt broke a while ago.

[ichudov]

(03-27-2018 )Chamberpains Wrote:  Sounds like I'd be saving some cash and in the mean time figuring out what exactly causes these engines to break head bolts. Then over engineering a more long term fix for all 6 heads at once. To hell with breaking down at any given time.

Is it poor grade of bolt? Improper torquing? To much cylinder pressure?

The repair man said that it is a bad design of these Mercedes engines and they break those bolts. Not sure exactly what could have been done differently, probably they could use more thicker and better bolts.

[Chamberpains]

Again, if broken head bolts are common I would inquire deeper. If you have potentially 30 bolts that can't do the job for the long haul then go find a better grade bolt or stud and have them all replaced with proper torque procedures done. Having large pieces of metal free floating in with the valve train on a running engine is not gonna fare well for that engine. It didn't do to well once for you let alone 29 more times. I wouldn't be able to sleep at night till i ensured I had something I trusted under the valve cover.

[Rawze]

Aside from quality, there are many causes of broken head bolts. Most of the time it is excessive power or cylinder pressures or over-torquing by some moron that is air-gun happy. It is not until all head bolts are torqued exactly the same that they will work in tandem to support the stresses equally. Otherwise, it is very easy for only one to break, then the rest will start failing under the heavier strain.

Excess cylinder pressures can cause it too. Bad injectors, bad programming, attempts to "turn up the hp" incorrectly, detonation problems, excess air intake temps or excess EGR temps into the intake,.. the list goes on.

A lot of shops blame "its a weak design" on things without really investigating why,.. they only complain and make more mistakes and assumptions and blame everything but what is really wrong, then perpetuate this through the spread of bad information. It always burns my arsse when shops tell customers this kind of thing.