Community Forums

Janshark · 10-13-2009, 02:45 PM

I am the owner of a 1991 Beaver Marquis pusher coach with a Cat engine with 88,000 miles on it.

Recently I had to have some major repair work done – new exhaust manifold and a new turbo charger. The turbo has a hole blown out of the side of it and when it was removed the mechanic found the manifold needed replacing too. The Cat mechanic told me that there was insulation wrapped around both of those components and that the insulation likely caused the problem because the components became too hot. He checked into it further and found that that this was something done by the rv manufacturer and not the coach manufacturer. Apparently it was regularly done by Beaver and Monaco, possibly in an effort to keep the bedroom cooler?

After repairing my coach, the mechanic put insulation back on the manifold and turbo charger but he warned me that the parts would likely fail again due to excessive heat.

What I would like to know is if anyone else out there has heard of this before or has the same thing on their unit. And if so, has anyone taken the insulation off the manifold and turbo and what effect has it had.

Personally, I’m inclined to remove the insulation because I don’t want to get hit with another $8,000 repair bill.

Any input in this regard would be appreciated.

helgi · 10-13-2009, 03:19 PM

Janshark,
If you take the insulation off how close are you to the surounding containment walls ie floor of bedroom etc? If there is enough space would it be possible to install noise dampening paneling we did use that in control centers in the mill and they consist of a foam panel with lead sheet in between 3/4 thick and they work very well you then can glue a heat deflecting cover over that. Might be cheaper than $8000. and you can do it yourself. Hope that this might get you thinking in the direction of insulating and cooling of the motor compartment.
Good luck.

Helgi.

LargCarPilot · 10-13-2009, 04:21 PM

JanShark,
The mechanic that told you the damage was caused by the insulation was ill informed. I have operated large bore diesel engines 40+ years and have always wrapped the exhaust head pipe and turbocharger to hold the heat in. The exhaust from a diesel engine is still burning when in exits the exhaust manifold and feeds into the turbo. The turbo housing is made of cast iron while the turbo impeller blades (on the hot side) are made of titanium or inkenol. As a diesel engine is truly a heat pump holding the exhaust heat in the manifold turbo, and exhaust pipe is a good thing. It also creates a scavenging effect, thus moving the burned fuel mix out of the exhaust pipe. I.E. Heat travels to cold.

The insulation serves two purposes. One is keep high heat out of your coach and to provide sound deadening. A diesel engine exhaust operates in the range of 600-1200 degrees. The surface of the exhaust manifold if viewed in the dark after pulling a long mountain grade would be a dull red color from the exhaust temperature. As I have had many Cat engines over the years I would be interested to know where the hole in the turbo was! Cat for years has had a gasket between the exhaust manifold flange and the turbocharger flange that is notorious for loosing up and blowing out. When it does the hot exhaust gases will eat away the flanges until both manifold & turbo need replacement. I doubt that you would ever hear the leak with manifold insulation and a diesel pusher. You would need to look for exhaust leak tracks on the insulation or around the manifold when you are looking in the engine bay.

In summary I would recommend that you replace the exhaust wrap. IMHO is a really, really good thing. Oft times young mechanics do not understand the nuances of a diesel engine due to lack of experience. The coach manufacturers most time don't provide the insulation due to cost. I have attached a link that may provide some insight by another coach owner that had a really good experience.

Good luck!

LargCarPilot · 10-13-2009, 06:12 PM

http://www.irv2.com/forums/f115/heat...ine-56306.html

This is what I did for the bedroom heat. (From a previous post)

I am one of the many Camelot owners that have the hot bedroom syndrone. I had the factory rear vent installed, and at the same time they removed and replaced the deteriorating foil insulation. I then installed a heat shield over the turbo and exhaust. These all helped, but still had to vent the bedroom after each day's drive.
So, last month I started talking to Advanced Thermal Products, Inc. (Advanced Thermal Products), as I saw they had a wrap for a ISL370. But it turned out to be a different exhaust/turbo configuration than the ISL400. Roberto, at ATP even went to a local RV dealer to take some measurements of an ISL400, but salesman wouldn't let do it as he wasn't a buyer.
Now, as my friend, Terry, was going to LA Thursday for some RV furniture, so he stopped by ATP and Roberto spent 3 hours measuring his 08 Scepter. Roberto called me with a price and I said go ahead, setting an appointment to be there Wednesday. They let me park overnight in their lot, so they could start on a cool engine at 7:00 am. Two employees tackled the wrap while the owner, Tim Thompson, spent the next 4 hours with me, showing what they do and how they do it. What an operation! They had to make some modification to mine during install and as they did, they saved it the computer. Once they were satisfied with the installation and fit of mine, they made Terry's and I was headed home by 1:00 PM.
As I had 5 hours sleep the night before, I got the nods about 3 1/2 hrs into the trip home. So, I went to the bedroom and it wasn't its normal toasty self - instead very comfortable. The outside temp was 85* and I wasn't towing, so the proof will come when I go to Branson the end of May. But it is a super improvement already.
Today I put Terry's wrap on and every piece fit perfectly. Those folks have talent.

The three separate pieces; exhaust pipe elbow, turbo housing & exhaust manifold. The exhaust elbow piece starts at the turbo and ends just before turning under the engine.

An inside look at the insulation
http://www.irv2.com/attachments/phot...dium/ATP_3.JPG

Installed ISL400
http://www.irv2.com/attachments/phot...dium/ATP_1.JPG

The plate they put on each piece
http://www.irv2.com/attachments/phot...dium/ATP_4.JPG

They make the wrap in 1100* and 1400*. Mine is the 1100* one and cost $693 for the three pieces. The price can go up or down depending on the length of the exhaust elbow piece. Camelot/Scepter exits on the right, whereas the Dip/Endevor exit left.

Visit Advanced Thermal Products for many more details. These guys are great and understand motorhomes.
__________________
Harry & Sheryl

2008 Camelot 40 PDQ