Two years ago a friend with an 06 35' Winnebago with approximately 35k miles had two pistons with holes burned through. A short block was installed. Last week, about 8k miles since it was replaced, it started pinging witch quickly developed into a knock. Inspection camera showed #4 with broken upper ring land and pieces of the ring on top of the piston. My 01 8.1 has 101k miles on it. I'm wondering has anyone else had this kind of problem with their 8.1 ?

GM big blocks tend to be pretty durable, but stuff happens. Was the replacement motor a truck motor?

Very unusual. Bad luck for this RVer.

unusual to say the least, but I have heard of more issues with the GM engine than Ford, and there are a hell of a lot more fords out there than GM 8.1's

I have a 7.4 so cannot directly 8.1 issues. I have nearly 200,000 with no engine or transmission issues.Sure sounds like it could be some kind of operator error!Some operators do not maintain there rigs and abuse them by pushing them way too hard.

We have 73000 miles on our 2004 Allegro Bay with 8.1 Workhorse. The engine runs just fine with very little oil use. We want it to last many more years for us.

Workhorse 8.1 engine problem/history | Good Sam Community

donn0128
Explorer II
May 12, 2017
GM big blocks tend to be pretty durable, but stuff happens. Was the replacement motor a truck motor?
Lwiddis
Explorer II
May 12, 2017
Very unusual. Bad luck for this RVer.
hanko
Explorer
May 12, 2017
unusual to say the least, but I have heard of more issues with the GM engine than Ford, and there are a hell of a lot more fords out there than GM 8.1's
enblethen
Nomad
May 13, 2017
I have a 7.4 so cannot directly 8.1 issues. I have nearly 200,000 with no engine or transmission issues.
Sure sounds like it could be some kind of operator error!
Some operators do not maintain there rigs and abuse them by pushing them way too hard.
Escapade
Explorer
May 13, 2017
We have 73000 miles on our 2004 Allegro Bay with 8.1 Workhorse. The engine runs just fine with very little oil use. We want it to last many more years for us.
K_Charles
Explorer
May 13, 2017
Whatever the problem was it didn't get fixed when they replaced the short block. It is still the same problem so it didn't happen twice only once. They should find out the cause be for replacing parts again.
wa8yxm
Explorer III
May 13, 2017
I recall a few years back a post by the rep from Redlands RV.. Redlands is one of the Ultra Power upgrade dealers.

They had, as I recall, half a dozen 8.1's come in with the kind of damage you cit, all of "Warranty age">> Half of them had the Ultra Power Upgrade, half were "STOCK" Workhorse warranted the half that were Stock. but blamed UP for the other half.. (Redlands took care of 'em)

I had a different issue with my 8.1.. Due to an external issue (not an engine fault) IT went BOOM, turned into a "V-6" and sized (Mechanic said there was no evidence of the last two pistons.. I thought there was but he says there was not. Oh well, don't matter) The new engine ..... Purrs like kitten. (And roars like lion going up hills... Just like the old one before the disaster).
MARKW8
Explorer
May 13, 2017
I does sound like a timing or a lean fuel problem.

Mark
Williebago
Explorer
May 13, 2017
We have 97,000 miles on our 2002 chassis and have had the check engine light come on before and it indicated knock sensor. I usually fill with standard 87 octane, but if I am going to be towing, then I fill with mid-grade 89 Octane fuels. I am trusting their marketing literature that the 8.1 and Allison are a 200,000 mile power train.
BigRabbitMan
Explorer
May 13, 2017
MARKW8 wrote:
I does sound like a timing or a lean fuel problem.

Mark

Concur.