Workhorse 8.1L engine problems

[VA Traveler]

My RV is a Holiday Rambler Traveler model 26RK with an 8.1 L Workhorse P32 chassis. I purchased the RV new in 2006 even though it’s a 2003 model. The coach had 900 miles on it in 2006 and today I’m at 42K miles.

Problems:
18K miles broken exhaust manifold bolts, an extra loud engine, but it appeared to be running ok.

35K miles: engine misfires under load. Replaced all sparkplugs and sparkplug wires.

41K miles: engine misfires at idle and under load. Replaced broken exhaust manifold bolts and installed the Workhorse Cooling Vent Kit. The kit included new sparkplugs wires.

This summer I will be taking a 4-5K trip; hopefully the cooling kit will help the situation. My engine compartment is very restricted. The question is: Is HEAT the real culprit or am I looking at a Monday morning problem?

What make this more frustrating are the Auto Park Brake problems I’ve had throughout the last 20K miles. Three instances involving:
reservoir sensor
retracted sensor
relay in the circuit.

[DriVer]

Originally Posted by VA Traveler

The question is: Is HEAT the real culprit or am I looking at a Monday morning problem?

VA Traveler, welcome to iRV2. Please do come back to visit us often.

I would like to take a shot at answering your question however I am not familiar with a Monday morning problem that you are referring to. In your post you offered that your engine compartment is very restricted. How is your compartment restricted? One other feature that was seen on HR rigs, not sure what year, was a perforated stainless steel plate (decor) that in my opinion does not allow enough air to get to the cool pack. Could this feature be a component of your current body style?

[VA Traveler]

Monday morning simply refers to something manufactured 1st thing Monday morning after a long weeked. Probably more mith than fact.

What causes bolts to sheer off?

Behind my grill area are the two radiators with only 8 inches or so space at the top between the coach and radiators. Above my grill is the front access panel, it is directly in line with the 8 inch area at the top of the radiators. Of course this is a solid access panel. The inside cover is about 8 to 10 inches above the top of the engine.

I don't see any type of panels, but it is very difficlt to see much around the engine.

[DriVer]

Originally Posted by VA Traveler

What causes bolts to sheer off?

Without seeing first hand what the studs look like it's difficult from here to give you a great answer however if there are heat issues with the engine compartment, expansion and contraction I expect is prime cause for this event. I have had a bad head gasket and when they removed the manifold, they broke 2 studs. A welder was called in who extracted the studs. The manifold was restored and I've been good ever since.

Behind my grill area are the two radiators with only 8 inches or so space at the top between the coach and radiators.

Is the space at the top of the radiator between it and the coach body covered by a rubber fabric shield? As far back as 2003 the material that was used was practically paper thin and it would shred in quick order. The new rubber material is a fiber reinforced sheet that will hold up well for the lifetime of the vehicle I expect.

I cannot tell you how critical it is that this space be covered. What is required is that all the air that enters the grill area needs to go through the radiator and none or little of it should be allowed to bleed over the top of the radiator.

Workhorse parts does have the rubber which they call a fabric that can be purchased and installed by the dealer.

Above my grill is the front access panel, it is directly in line with the 8 inch area at the top of the radiators. Of course this is a solid access panel. The inside cover is about 8 to 10 inches above the top of the engine.

I don't see any type of panels, but it is very difficult to see much around the engine.

If you can take a picture of what that looks like perhaps that can help all of us achieve a better response to your problem.

Here is what the fabric looks like ...

[VA Traveler]

Thanks for your input. The picture you provided looks nothing like the inside front of my RV. I will take some pictures and post them. My RV is in storage so it may take a day or so..

During my last repair, while replacing the broken manifold bolts,they also installed a new gasket. I assume this is standard practice?

[DriVer]

Originally Posted by VA Traveler

During my last repair, while replacing the broken manifold bolts,they also installed a new gasket. I assume this is standard practice?

VA Traveler, Yes sir you are going to want to have a gasket there.

[Full-Timers]

The "vent kit" solved all my plug wire problems.

[DriVer]

Originally Posted by Full-Timers

The "vent kit" solved all my plug wire problems.

The vent kit was totally an internal design and application of a solution that quickly resolved a problem. This was Chris Christy's contribution toward this problem. In my observations, the Vent Kit has been successful in the vast majority of the applications where it has been applied however there have been some rigs that couldn't be cooled using a 4 blade Hamilton Standard prop. The small amount of rigs where the application has failed speaks toward the engine enclosure not providing adequate air flow through the cool pack.

[bdaball]

DriVer,
Hey Mike, that's not dirty brakefluid I see in your master cylinder in that picture is it?

FYI, A quick trip to the tire store for an old discarded truck tube works pretty good also.

[DriVer]

Originally Posted by bdaball

Hey Mike, that's not dirty brakefluid I see in your master cylinder in that picture is it?

At the time I took that picture, you're right! I had not changed my fluid yet1 Since then I have nice clean fluid!

[inspectorudy]

Driver I have the same reservoir on my Adventurer. I just bought the Motive pressure brake bleeder and found out through the company that makes the reservoir is Chrysler. Why they went with two caps is a mystery since one would have worked fine. Motive will give anyone with this setup a bleed fitting and a dummy with no vent in the top. I bled all four wheels in about forty minutes by myself.

[VA Traveler]

Here are a few pictures:
1. Outside front of RV, note the new cooling intakes mounted on the lower grill.
2. Inside engine/fan area. Notice the angle iron frame above the fans, and the black insulating material on the sides.

[scoutmstr]

For what it's worth, I understand that Workhorse wants 550 square inches of open grill area. Even with that, the air must be directed through the radiator. After installing the sparkplug vent kit copied by me from WCC's kit I installed complete rubber shroud from engine up to firewall leaving only a 1' hole for the PCM and TCM. The 1" hole was after talking with my contacts at GM. I then covered the complete passenger side from the radiator out to the body. Still working on drivers side and area below radiator. This is after a plug wire burnt in Alaska in '05. I want all air through grill opening to go through the radiator, none around.

The only thing I was told with the vent kit is to make sure the sparkplug end of the vent hose points directly into the sparkplug not along side. I'm still running seven original OEM wires with a replacement OEM wire on #5. The extra set of OEM wires I bought and carry now have 20000 miles on them in the storage compartment, just in case.

[wa8yxm]

Re-Reaqding the O/P's post I have a question.

Is this engine "Stock" or has it been "Chipped"?