Who has had a 8.1 Failure ?

[MntDriver]

28,500 miles, All stock except for new NAPA HD wires, Mobil 1 5W-30 at 5,000 miles, and unit runs like a champ! All my miles are usually above 7,000 feet elevation, and very hard miles at high altitude towing a car.

I did have an Ultrapower ECM tune for approx. 4,500 of those miles, and then received a refund along with an OEM ECM tune.

[ruppr]

Well, just as an update. $2,719.69 quote for a ring & valve job. (Unless they find something else) {All believe it was caught before further damage.}

Again, 30,000 miles, cylinder one no compression and plug oil fouled, cylinder's 4 & 8 wet with oil. I was using a quart of oil about every 1,000 miles. Oil passing the oil/compression rings at 30,000 makes me question the ring seating to began with and would explain why some of you are using so much between changes.

And yes, this engine/rig has been babied.

Best,

ruppr

[RustyJC]

Bob,

With zero compression, did they find a broken/dropped valve or a holed piston? I wouldn't expect "normally" worn rings or valve recession to give a zero compression reading.

Rusty

[dieselclacker]

Quote:

Originally Posted by RustyJC Bob, With zero compression, did they find a broken/dropped valve or a holed piston? I wouldn't expect "normally" worn rings or valve recession to give a zero compression reading. Rusty

My thoughts exactly. Perhaps a compression test that was poorly done, or a faulty gauge? If the cylinder truly does have zero compression, it has to be going somewhere.

Dieselclacker

[ruppr]

Actually I'm waiting to hear also. (I'm hoping for a bad (somehow suddenly) exhaust valve. I was there when they reran compression check and showed me the plugs. They waited for my OK on the above (estimated) amount for my approval to proceed. All cylinders were within 10% of each other except (4) 14% and (8) 17%.

Like I said, definite miss and pinging started about 20 minutes out of Kingsville after gassing up on way back from South Padre.

Suppose to pull the heads Monday-----

Best,

ruppr

[Bug512]

In my past life when I was a mechanic I would use a cylinder leak down tester. You could identify where the problem is, valve or rings/piston.

BTW we made it to Tennessee without any issues. Drove 750 miles in one day with ambient temperatures in the 94-97 range. Engine temperature 198-207, trans mission was running at 160. 60 MPH, 7.5 MPG with the generator running several hours for additional cooling.

[dieselclacker]

Bob,

I don't quite see how they could give you an estimate of 2719.69 for a ring and valve job on your engine. If it really does have zero compression on one of the cylinders, they have not pulled the heads, or run a leak down test on the cylinders, how could they possibly make an accurate estimate for repairs. Could be a really bad cylinder score from a burned piston for instance, or a hole punched in a piston from a stuck valve etc. I hope for the best for you in getting it up and running again.

Dieselclacker

[iRV4FUN]

The GM 8.1L engine was not exclusively built for the RV industry. The 8.1L has a lot of proven reliable miles on them. You can find similar 8.1L’s in the Suburban, Silverado, Hummer, ect...

When Workhorse transferred ownership over to the body builder we start to see issues. Issues such as excess heat and burnt spark plug cables. And so I wonder if we are dealing with excess heat due to a poor design by a couple of poorly designed dog houses and or air dams.

The boat people figured this out a long time ago. You can purchase cooling fans for inboard motors. Workhorse came up with a passive air system a few years ago.

Anyway we all have different body builders and so we have different experiences. Some catastrophic and some very expensive.

My doghouse gets very hot and after a day’s drive the heat doesn’t dissipate for several hours. Now if I had a set of boat fans, my RV would cool down a whole lot faster. I used a passive system and it helped. I added insulation to my doghouse and that really helped. Could it be we are dealing with a similar issue that our boat friends figured out a long time ago?

So who has the best motorhome?

YouTube - ‪Extreme motorhome racing - Top Gear - BBC‬‏

[max49]

We've gone through IP, Brake and SP wire problems and now we have 3 different threads on IRV with blown 8.1 engines.
Oh well, we gave up on resale value a long time ago.

[DriVer]

Quote:

Originally Posted by max49 Oh well, we gave up on resale value a long time ago.

I won't worry about resale value since they will have to pry the steering wheel from my cold dead hands.

92,800 miles and still workin' .....

[Wayneey]

31,099 miles, everything stock except Mobil 1 5W-30 at about 10K miles, and stainless steel exhaust tips (makes the rig go faster w/o using any more fuel ...). During the last 3,000+ mile trip from CO-NM-AZ-CA-NM-CO, used about 1/2 quart of oil, towing an 08 Honda CRV. About 50% of miles are at altitudes >5,000 ft. Gas mileage is consistent at ~7.5MPG towing, better when not towing, sometimes worse with heavy winds and the like.

Based on some of the information in this thread, I ordered a Scan Gauge II from Oemy (received yesterday) to better monitor engine parameters. Now, where are those instructions ...

Wayne

[John47]

Have just passed 40,000 miles using Royal Purple Synthetic oil for 37,000 miles. No mods, all stock. Also just had 4 Koni shocks installed (ride improved) No problems and going strong.

[max49]

Quote:

Originally Posted by DriVer I won't worry about resale value since they will have to pry the steering wheel from my cold dead hands. 92,800 miles and still workin' .....

I'll admit yours and Eds' have been good ones, possibly the record with 8.1s. There isn't that much to maintain in the internals so I believe you guys have been a little lucky, unless there is something different about the engines.
In Co, my engine works hard in the mtns, but, I only have an 18,000lb chassis, so that's kind of a wash compared to the 22 to 26K chassis with the same engine, IMO

[iRV4FUN]

The GM 8.1L engine was not exclusively built for the RV industry. The 8.1L has a lot of proven reliable miles on them. You can find similar 8.1L’s in the Suburban, Silverado, Hummer, ect...

When Workhorse transferred ownership over to the body builders we start to see issues. Issues such as...


"The following is an important bulletin from Workhorse CC

Engine Overheating – All Models

4-10-2008

Complaint/Condition

Engine is damaged from overheating due to low coolant level. This normally occurs within the first 2000 miles (Early failures) or after 2 to 3 years (late failures)

A. Early Failures
Body builders add heaters or other equipment that leaves air pockets in the coolant system. Both the overflow reservoir and radiator falsely suggest that system is full of coolant. After extended use, the air pockets work out and the radiator tank is low. This can occur without drawing coolant from the overflow reservoir..."

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